by high river discharge, (2) a massive bloom of the dinoflagellate Ceratium
tripos which lasted from February to July, (3) lack of storms moving
through the area in spring, and (4) disruption of the typical southwest-
ward currents resulting in aggregation of organic particulate material
(including C. tripos) in the area.

The role of some of these conditions in generating the hypoxia of
1976 can be seen by considering the normal annual cycle of dissolved oxygen
in the bottom waters as described by Armstrong (1979) for the New Jersey
shelf waters, along with the annual cycle of stratification and with con-
ditions that were observed in 1976 (Fig. 12). During fall and winter the
bottom waters on the continental shelf of the Middle Atlantic Bight become
saturated with oxygen as overturn of the water column from cooling at the
surface mixes oxygenated surface water with the bottom water. With the
onset of stratification in spring by vernal warming and increased river
discharge, vertical replenishment of oxygen to the bottom water becomes
inhibited. Dissolved oxygen concentrations in the developing cold pool
decline as utilization exceeds replenishment. With strengthening of
stratification through summer, oxygen content near the bottom rapidly
declines until fall overturn begins to break down the stratification
and replenishes the oxygen.

Typically, dissolved oxygen concentrations in bottom water reach
annual maximum values of about 7 m1"! throughout the Middle Atlantic
Shelf in March and annual minimum concentrations in August of about
3 met! off New Jersey and about 4 ml.1-1 for the bottom waters off
Long Island (Armstrong, 1979). Experiments reported by Thurberg and

Goodlet (1979) indicated surf clam mortality in water of dissolved oxygen

55


Cook, G. S. 1966. Non-tidal circulation in
Rhode Island Sound. Orift Bottle and
Sea-Bed Drifter Experiments (1962-1963).
U.S. Naval Underwater Weapons Research
and Engineering Station Tech. Memorandum
TM 369, Newport, RI., 44 pp and 34
illustr.

The non-tidal circulation in Rhode Island
Sound shows seasonal variations at both the
surface and bottom. During spring, the sur-
face drift is primarily toward the east and
north, while the bottom drift is toward the
northwest. During surmer, the surface drift
tends northerly, with secondary components toward
the east and west, reflecting the effect of a
cyclonic eddy. Bottom drift during the summer
is similar to that observed during the spring.
During autumn and winter (little data was ob-
tained during the winter season), the surface
drift tends offshore, while the bottom drift
tends onshore.

The features of the drift patterns are
discussed in the light of river effluent,
advection and meteorological effects. Typical
drift speeds at the surface ranged from 2 to 14
kn/day while the bottom drift speeds were from
0.1 to about 3 km/day.

Based on the seasonal pattern and other
persistent features of non-tidal drift, a test
firing area, which offers the best probability
for ultimate recovery of a lost test vehicle,
is suggested.

Cook, S. K. and C. £. Gardner, Jr. 1978. An example
of rapid change in the summertime water column
over the continental shelf southeast of Sandy Hook

N. J. Gulfstream 4(5):6-7.

Cook, S. K. and M. M. Hughes. 1980. Water column
thermal structure across the shelf and slope
southeast of Sandy Hook, New Jersey. Annales
Biol. Cons. Int. Explor. Mer. 35 (1 Hydrography):
4-25.

119

Cornilton, P., M. Reed, M. Spaulding, C. Swanson.
1980. The application of SEASAT-1 radar
altimetry to continental shelf circulation
modeling. Proceedings of Symposium on remote
sensing of the environment, San Jose, Costa
Rica, 23-30 April 1980.

This study investigates the applicability of
high resolution radar altimetry to numerical
modeling of continental shelf circulation. The
Georges Bank/Gulf of Maine region, one of the
richest fishing grounds in the world and currently
being considered for o11 exploration, was selected
as the test site.

Radar altimetry is employed in verifying
predictions of the continental shelf circulation
model. SEASAT-1 radar altimetry has been selected
over GOES-3 altimetry because of its higher resolu-
tion, a necessity for observing elevation changes
on the shelf, and because of its repeating orbit,
which provides a convenient means of improving
the GEM-10b geoidal estimate in the Georges Bank/
Gulf of Maine region.

Details of the numerical circulation model
to be used in the analysis are presented else-
where. In overview, the model is three dimensional
in nature and incorporates a vertical coordinate
transformation to resolve the surface and bottom
layers. Although for this investigation, tidal
forcing only was used, the model is capable of
responding to all significant forcing mechanisms
on the shelf (tides, wind, atmospheric pressure
and density gradients). The model makes use of
the efficient semi-implicit mode of time integra-
tion, removing the surface gravity wave time step
restriction.

Verification of the predicted surface elevation
is achieved through a comparison of model and alti-
meter derived values of this quantity on two SEASAT
tracks passing through the study area. For this
comparison tidal gauge data along the shelf break
were used to drive the model while open ocean
tidal data were used to correct for SEASAT orbital
bias and tilt. The comparison is in general excel-
lent, the only problems being. in the absolute
magnitudes of the sea level. This problem appears
to be attributable to errors in the bias and tilt
correction rather than errors in the circulation
model.

Cornilton, P. C., M. L. Spaulding and K. Hanson.
1979. Oil spill treatment strategy modeling
for Georges Bank. American Petroleum Inst.,
Oi] Spill Conf. Proc., p. 685-692.

Costin, M., P. Davis, R. Gerard and B. Datz. 1963.
Dye diffusion experiments in New York Bight.
Columbia University, Lamont Geol. Obs. Tech.
Rep. CU-2-63 (Unpub. Man. )

Cox, J. and P. H. Wiebe. 1979. Origins of oceanic
plankton in the Middle Atlantic Bight.
Estuarine Coastal Mar. Sci. 9:509-527.

* — This article analyzes documented occurrences of
oceanic and other non-indigenous zooplankton in the
New York Bight as well as recent knowledge on warm
core rings in order to trace the origins of plank-
ton in this region. It presents an objective
analysis of previous works in the field and provides
a conceptual framework for plankton dynamics in the
Middle Atlantic Bight.


Connecticut River Plume

Fresh water discharged by the Connecticut River (560 m3-sec”! mean
discharge) passes into New York Bight via the eastern end of the Long Island
Sound (Garvine, 1975). The Connecticut River's mean rate of discharge is
about the same as that of the Hudson River, and its plume has been shown
to affect salinities of shelf waters south of Montauk, Long Island (Ketchum
and Corwin, 1964). High river discharge during spring runoff results in
shelf salinities about 2 °/oo less than those during low discharge periods.

This effect extends to a depth of 60 m south of Montauk.

Gulf of Maine Tributary Plumes

Even though total river discharge from New England (including Connecticut)
is double that of the Hudson and Delaware systems combined and about thirty
percent larger than that entering Chesapeake Bay (Miller, et al., 1963), it
is distributed among a large number of small rivers. This is particularly
true for tributaries to the Gulf of Maine. As a consequence, distinct major
plumes aren't observed there; the many small plumes blend into a relatively
narrow coastal band of low salinity instead. No publications dealing with
plume configurations in the Gulf of Maine were found in the literature search
associated with this study.

Studies of hydrographic and current meter data collected in Massachusetts
Bay reported by Butman (1978) showed that the low frequency currents in this
portion of the Gulf of Maine are dominated in the spring by flow from the
Merrimack River. The river enters the Gulf of Maine about 30 km north of
Cape Ann, the northern edge of Massachusetts Bay, and its plume flows south-
ward around the cape into the bay where it forms a lens of relatively fresh
water. The density field associated with the lens causes clockwise circulation

(geostrophic) around the lens.

21


O'Connor, T. P. and P. K. Park. In press.
Consequences of industria’ waste disposal
at the 106-Mile ocean waste disposal site.
In: Ecological Stress and the New York Bight:
Science and Management, G. F. Mayer (ed.).
Estuarine Research Federation.

Industrial wastes are dumped beyond the edge
of the continental shelf at the 106-Mile Ocean Waste
Disposal Site. These wastes are mainly liquids
that, in some cases, forma precipitate floc after
mixing with seawater. Rather than descending to the
sea floor, wastes are distributed primarily as
plumes within the upper mixed layer. The method of
dumping yields a plume with a maximum initial
concentration of about 200 ppm waste. Within
about four hours, the maximum concentration is
reduced to approximately 10 ppm with a waste plume
width of about 1 km. Further dilution and plume
growth proceed slowly, leading to the conclusion
that storm events may be necessary to dilute ex-
tensively the waste. The average flow through the
dump site seems to be sufficient, when compared
to the frequency of dumping, for each dump to be
an independent event so that later dumps do not
occur in previously created plumes. It is estimated
that, on the average, the plumes move toward the
southwest along the contour of the continental
shelf.

Laboratory studies have shown that oceanic
strains of phytoplankton are less tolerant of
waste than coastal strains of the same species,
and that there is considerable variation in
response to waste among species. Although no
tested phytoplankton species have been found to
be affected at 10 ppm waste, it is possible that
within a waste plume there will be a readjustment
of phytoplankton conmunities favoring more resilient
species. Tests of this are proceeding, as are
tests on the sublethal responses of zooplankton
to wastes, histopathological and chemical analyses
of field-collected organisms, studies of the
stability of waste-derived organic compounds,
and studies of the partitioning of waste constitu-
ents between dissolved and particulate phases.

Oertel, G. F. and T. L. Wade. 1981. Characteristics
of total suspended matter and associated
hydrocarbon concentrations adjacent to the
Chesapeake Bay entrance. In: Chesapeake Bay
Plume Study: Superflux 1980. J. W. Campbel?
and J. P. Thomas (eds.). NASA Conf. Publ.
2188.. NOAA/NEMP III 81 ABCDFG0042. NTIS,
Sprinofield, Virginia. 522 pp.

150

Olbers, D. J. 1981. A formal theory of
internal wave scattering with applications
to ocean fronts. J. Phys. Oceanogr.
11(8): 1078-1099.

A concise theory for scattering of internal
waves at localized inhomogeneities (ice. ,
topographic features, baroclinicity in the
density field, variations of the mean sea level,
Jetlike currents) in the oceanic waveguide is
presented within the formal framework of quantum
mechanical scattering theory. The equations of
motion of the wave system are reduced to a form
resembling the Schrodinger equation with an inter-
action operator describing the effect of the
ambient inhomogeneities. By standard Green's
function techniques integral equations for the
scattered field and its Fourier transform (which
relates to the amplitudes of the scattered waves)
are derived, both for a scattering region of
finite extent (representing a two-dimensional
scattering problem) and a "wall-like" scattering
region of infinite extent (representing a one-
dimensional scattering problem.) As an example,
the theory is applied to the scattering at a
straight geostrophic front. The far-field

is described in the Born approximation valid for
(U/c) (kL3) €1, where U is the speed of the
geostrophic current of width L3, and c and k are
the phase speed and wavenumber of the incident
wave. It is found that the scattering process
has a significant directional signature while
modal redistribution appears to be weak.

Orr, M. He, L. Baxter, II, and F. R. Hess, 1980.
Remote acoustic Sensing of the particulate
phase of industrial chemical wastes and
sewage sludge. Woods Hole Oceanographic
Inst. Tech. Rep. 79-38, 153 pp.

Orr, M. H. and F. R. Hess. 1978. Remote acoustic
monitoring of industrial chemical waste
released at Deepwater Dumpsite 106. J.
Geophys. Res. 83:6145-6154.


Mayer, 0. A., Mofjeld, H., and Leaman, Kevin D.
1981. Near-inertial internal waves observed
‘on the outer shelf in the Middle Atlantic
Bight in the wake of hurricane Belle. J.
Phys. Oceanogr. 11:87-106. (January 1981).

On 10 August 1976 Hurricane Belle passed
rapidly over the highly stratified shelf of
the New York Bight. Records from Aanderaa
current-meter moorings show that the response
to the hurricane depended strongly on bathymetry.
At deeper stations (~70 m depth), intense
first-mode, internal near-inertial oscillations
were generated at frequencies ~1% less than the
Jocal inertial frequency. At shallower stations
{~50 m depth), only weak, heavily damped second-
mode oscillations were observed in the current
records, with no corresponsing inertial signals in
temperature. In the Hudson Shelf Valley,
inertial motion occurred only near the surface.
This was probably due to topographic effects.
The divergence and curl of the wind stress
contributed equally to the forcing. The
response at the deeper stations is consistent
with Geisler's (1970) theory for the
open ocean in which a hurricane leaves
a wake of internal-inertial oscillations
if it travels faster than the internal
phase speed and if its horizontal scale
4s comparable to the internal phase speed
and if its horizontal scale is comparable
to the internal Rossby radius. The observed
frequency shifts (subinertial motion) and
observed relative vorticity are consistent
with Mooer's (1975a) theory that relative
and planetary vorticities combine to aive
an effective inertial frequency. Here it
is suggested that lack of strong inertial
motion at the shallower stations is due to
a lack of resonance and the likelihood that
frictional effects are more important in
shallower water, resulting in a more
heavily damped response.

McClennen, C. E. 1971. Wave and current
effects on continental shelf sediments.
Grad. School Oceanogr., University of
Rhode Istand Rep. (unpublished).

McClennen, C. E. 1973. New Jersey continental shelf near
bottom current meter records and recent sediment
activity. J. Sed. Petrol. 43(2):371-380.

Modern sedimentary processes associated with the
ridge and depression topography of the New Jersey
continental shelf were investicated with the aid of
near bottom current meter measurements and also
estimates of near bottom wave orbital velocities
derived from classical wave theory and available
surface wave observations. Four current meters were
set 1.5 to 2.0 m above sea bottom in 30, 59, 74, and
143 m depths for nine to eleven days during the late
springs of 1970 and 1971. The root mean square
speeds of the meter records were 13.7, 11.8, 12.9 and
19.5 cm/sec in order of increasing depth, with a
maximum recorded 2.5 minute average speed of nearly
40/cm/sec and net southwesterly transport. Both
current and wave data indicate reworking of the sur-
face sand cover on the shelf. In determining the
relative importance of wave vs. current activity the
true value of the critical erosion velocity is of
primary importance. The present day physical rework-
‘ing of the surface sediments is indicated independent-
ly by bottom photographs of ripples and by sedimentary
structures in box cores, with reworking being
generally limited to the upper meter of sediment.

No mechanism for the present formation of the larger
scale ridge and depression topography is indicated
by the currents measured or the wave considerations.

185

Nelellan, H. J. 1957. On the distinctness
and origin of the slope water off the
Scotian Shelf and its easterly flow south
of the Grand Banks. J. Fish. Res. Board,
Can. 14:213-239.

McWilliams, J. C. and G. R. Flier.
of isolated nonlinear vortices.
9(6): 1155-1182.

1979. On the evolution
J. Phys, Oceanogr.

The evolution of an isolated, axially symmetric vortex is
calculated with a quasi-geostrophic, adiabatic, hydrostatic,
B-plane, two vertical mode model. The circumstances of greates
interest are those of weak friction and large vortex amplitude
(strong nonlinearity). Systematic studies are made of the
consequences of varying the frictional coefficient, the vortex
amplitude, the vortex radius (relative to the deformation
radius), the degree of nonlinear coupling between the two
vertical modes and the initial vertical structure of the vortex

Results of note include the following. Within the approxi
mation of a single vertical mode mode? (i.e., in the absence
of modal coupling), a baroclinic vortex has an increased west-
ward and a finite meridional propagation speed when its amp-
Titude is greater than infinitesimal. Both of these speeds
however, are limited by the wave speeds (as determined from
infinitesimal amplitude theory) of the weak dispersion field
outside the vortex. The vortex amplitude decay rate, in the
limit of strong nonlinearity, is governed by the frictional
coefficient rather than dispersion. When vertical modal
coupling is included, the vortex propagation and decay rate
can be altered. Asymptotically in time, the vortex approaches
a state of deep compensation (i.e., beneath a shallow thermo-
cline, there is no flow in phase with the upper ocean vortex),
with a propagation velocity less rapid in the westward direc-
tion and more rapid in the meridional direction (compared to
a single mode vortex), and with a decay rate again controlled
by the friction coefficient. At earlier times, however,
more bizarre behavior can occur; for example, a vortex with
initially pure baroclinic mode vertical structure can behave
as an eastward-propagating vortical modon for a brief interval.

This study focuses on vortices whose baroclinic com-
ponent is of only one sign (a positive temperature extremum in
the thermocline); however, because of a symmetry of the model
chosen (in particular due to its quasi-geostrophic assumption),
these solutions can be simply reinterpreted to apply to
vortices of both signs.

Meade, R. H. 1969. Landward transport of bottom
sediments in estuaries of the Atlantic coastal
plain. J. Sediment. Petrol, 39:222-234.

* Estuaries between Cape Cod and Cape Canaveral
(Cape Kennedy) are examined for streamflow (1931-
1960) and sediment load (1909-1968). Sediment
load of rivers is deposited in the estuaries and
offshore sands also appear to be moving into the
estuaries. Rate of filling or alteration is a
function of both streamflow and sediment load.

Meade, R. H. and S. W. Trimble. 1974, Changes
in sediment loads in rivers of the Atlantic
drainage of the United States since 1900.
Int. Assoc. Sci. Hydrol, Pub. 113:99-104.

Meade, R. H., P. L. Sachs, F, T. Mannheim,
J.C. Hathaway and D. W. Spencer. 1975.
Sources of suspended matter in waters of
the Middle Atlantic Bight. J. Sedim.
Petrol. 45(1):171-188.


KOAA TECHNICAL MEMORANDUM NMFS-F/NEC

The Northeast Fisheries Center (NEFC) conducts targeted research to
provide needed information for fisheries resource and habitat managers in the
Northwest Atlantic. The NEFC operates facilities in Gloucester and Woods
Hole, Massachusetts; Narragansett, Rhode Island; Milford, Connecticut; Sandy
Hook, New Jersey; and Oxford, Maryland. It also administers the NMFS‘s
National Systematics Laboratory in Washington, D.C., and Atlantic
Environmental Group in Narragansett, Rhode Island. This targeted research
focuses on: (1) harvesting, aquaculture, and utilization of fisheries
resources; and (2) the health of the marine environment as it affects the
production and edibility of fisheries resources. Users of this information
include federal and state agencies, private industry, and the general public.

The real-time need for this information by decision makers often
precludes publication in formal journals. The NOAA Technical Memorandum NMFS-
P/NEC series identifies informal documents prepared by NEFC authors or similar
material prepared by others for NEFC purposes, where formal review and
editorial processing are not appropriate or feasible. However, documents
within this series reflect sound professional work and can be referenced in
formal journals. Any use of trade names within this series does not imply
endorsement, however.

Copies of this and other NOAA Technical Memorandums are available from
the National Technical Information Service, 5285 Port Royal Rd., Springfield,
VA 22161. Recent issues of NOAA Technical Memorandum NMFS-F/NEC are noted
below:

3. Definition of Management Unite. By Emory D. Anderson and Guy D.
Marchesseault. October 1980. v +4 p., 4 figs., 1 table.

4. Fishery Management Techniques, A Review. By Michael P. Sissenwine and
James E. Kirkley. October 1980. v + 10 p.

5. The Status of the Marine Fishery Resources of the Northeastern United
States. By Margaret M. McBride and Bradford E. Brown. December 1980. vii +
13 p., 4 figs., 3 tables.

6. Economie and Biological Data Needs for Fisheries Management, With
Particular Reference to the New England and Mid-Atlantic Areas. By Guy D.
Marchesseault, Joseph J. Mueller, and Ivar E. Strand, Jr. December 1980. v +
10 p., 1 fig., 3 tables.

7. Methodology for Identification and Analysis of Fishery Management
Options. By Brian J. Rothschild, Richard C. Hennemuth, Jacob J. Dykstra, Leo
C. Murphy, Jr., John C. Bryson, and James D. Ackert. December 1980. v + 10
pe, 5 figs., 1 app.

(continued on inside back cover)


Butman, Bradford. 1978.
On the dynamics of shallow water currents
in Massachusetts Bay and on the New Eng-
land continental shelf. Tech. Rep. WHOL
77-15. Woods Hole Oceanographic Insti-
tution, Woods Hole, MA 20543. 174pp.

Massachusetts Bay is a coastal Bay 100 km
long and 40 km wide located in the western
Gulf of Maine. The Bay is closed by land to
the north, west and south, but is open to the
Gulf to the east; the opening is partially
blocked by a shallow bank. The bottom sedi-
ment distribution in the Bay is complex; fine
grained material is found in the deep basin,
sand and gravel on the shallow bank and mix-
tures of sand, gravel and fine material near-
shore. Richardson current meters were moored
\mfrom the bottom over a one year period at
several locations in the Bay to study the
bottom currents and the equilibrium between
current and sediments. The current measure-
ments suggest that the bottom sediments can
be expected to move only occasionally in
certain areas, The maximum bottom speeds
are principally determined by the strong
tidal currents in the basin.

In winter, the near bottom currents are
dominated by wind stress associated with
strong storms, Bottom currents in the shal-
Jow areas are generally in the direction of
the wind while currents in the deep portion
of the basin are often opposite to the direc-
tion of the wind. Sea surface setup in the
direction of the wind is observed, as well
as absolute changes in sea level as the
Bay adjusts to changes in the level of the
adjacent Gulf of Maine. Adjustment of the
bottom currents to wind events requires
approximately 12 hours.

Moored current meter measurements and
synoptic hydrographic observations made
in Massachusetts Bay show that freshening
from the spring runoff dominates the low
frequency currents and the hydrography of
the Bay in the spring months. The major
freshening is attributed to the Merrimack
River which empties into the Gulf of Maine
30 km to the north of the Bay; discharge of
the Merrimack increases by at least a fac-
tor of two in spring. Flow directly into
the basin from several smaller rivers is not
important. Two major features are found: a
fresh surface plume confined to the upper
10 m of the water column which becomes more
distinct as the seasonal thermocline develops,
and a large deep fresh lens. Flow is clock-
wise around the deep lens and is consistent
with the thermal wind relation. Sustained
currents of 10 - 20 cné! with time scales

115

of 5 - 10 days were observed as the
deep lens (or lenses) slowly advected
through the basin. Current observations
made in the previous spring show simi-

lar low frequency behavior.

Two simple Tinear models of the semi-
diurnal tide on the continental shelf are
used to estimate the vertical turbulent
eddy viscosity, a linear bottom drag
coefficient, and the change in the bottom
drag a homogeneous water column with
constant eddy viscosity to a sinusoidal
body force with a slip bottom boundary
condition is presented. With measurements
of the tidal current at two depths, four
Parameters are shown to be independent
of the body force: the ratio of the clock-
wise current at two depths, the ratio of
counterclockwise current at two depths,
the change in the tidal ellipse orientation,
and the change in phase of the tidal ellipse.
Observations of the semidiurnal tidal cur-
rent on the New England continental shelf
are consistent with a vertical eddy viscos-
ity of 20.- 50 cm? sec-! and a bottom drag
coefficient of .02 - .05 cm sec. The
Ekman depth is thus 10 mand the integrated
adjustment time is approximately 28 hours.

An integrated linear model with linear
damping of the semidiurnal tide on the con-
tinental shelf, forced uniformly at the
shelf edge, show an increasing phase lag of
the tide at the coast with increased damping;
amplitude remains relatively constant over
a wide range of damping coefficient.
Observations of the tide at the coast during
storms a phase lag of as much as 10 degrees
for the semidiurnal tide. For approximate
dimensions of the New England shelf, this
implies an increase by a factor of 3 - 5 of
the bottom drag coefficient and an integra-
ted motion adjustment time of 6 - 9 hours.
Waves may be an important contribution to
the increased bottom stress.

Butman, B., R. C. Beardsley, B. Magnel1, D. Frye,
J. A. Vermersch, R. Schlitz, R. Limeburner, W. R.
Wright and M. A, Noble. 1982.
Recent observations of the mean circulation
on Georges Bank. J. Phys. Oceanogr. 12(6):
569-591.

A clockwise circulation around Georges Bank was
measured by means of moored current meters, aircraft-
tracked surface drifters, and satellite-tracked
drifters drogued at 10 m. The strongest flow was in
a narrow jetiike current (30 cm s~!) along the
northern Flank of the bank. The flow of shelf water
on the southern flank was westward (10 cm s-!)
toward the Middle Atlantic Bight; some of this water
flowed northward through the eastern side of Great
South Chane? and recirculated around Georges Bank.
The satellite-tracked drifters and the moored observa-
tions indicate that the circulation around the bank
was not completely closed and considerable variability
occurs in the trajectory of an individual water
particle.


A second depositional area is located about 110 km due south of Martha's
Vineyard covering about 2500 km2 of the continental shelf (Milliman et al.,
1980). This area has been termed the "Mud Patch” and is composed’ largely
of sand-silt-clay, sandy-silt and silty-sand (Wigley and Stinton, 1973).
Measurements of excess 2!0Pb from cores collected in the Patch and high
depositional rates measured by 14 dating (Bothner, et al., 1981) indicate
that the fine grained sediments are modern. The Patch "-- is the only
site of present-day natural deposition on the Continental Shelf off the
eastern United States, exclusive of the Gulf of Maine." known to those
authors. Organic content of sediments from this area is higher than in
surrounding shelf areas and may have higher values of trace metals
(Maurer, 1982). This is due to the natural sedimentation and sorptive
processes controlling fine arained deposition. This region contains a
high proportion of deposit-feeding benthos and represents a typical "soft-
bottom" community. The Mud Patch is surrounded by typical clean shelf sands
and the relief ridge and swale topography (Milliman, 1973).

The sediments in the Mud Patch are believed to be from recent
deposition resulting from a gradient in the tidal current speed across
the Patch (Twichell, et al., 1981). The material suspended by the strong
tidal currents over Georges Bank and Nantucket Shoals are carried into
the region by the mean southwestward flow, where tidal currents decrease
in strength toward the west to less than 10 cm-sec”! at the western edge
of the Mud Patch. These slower tidal currents are not able to kzep the
fine-grained material in suspension, thus the material settles out and

is deposited as the water moves southwestward across the Mud Patch region.

64



Mulholland, P. J. and J. A. Watts. 1982. Trans-
port of organic carbon to the oceans by rivers
of North America: a synthesis of existing
data. Tellus 34:176-186.

Transport of organic carbon in rivers of
North America to the oceans was assessed by com-
piling and anlyzing data from 82 North American
rivers draining 60% of Canada and the United
States. These data were collected by the U.S.
Geological Survey and the Water Resources
Branch of Canada's Inland Waters Directorate.
Mean annual concentrations of total organic
carbon showed considerably less variation than
did annual specific export (gC m7? yr@!)
Regional variation in annual specific export of
total organic carbon was attributed primarily
to differences in annual runoff, Transport of
total organic carbon to coastal regions by
North American rivers totalled about 35 X 1012
+5 X 10"? gC yr-? in 1977 and 1978, The
total organic carbon flux to the oceans asso-
ciated with the long-term average annual flow
in North American rivers was computed to be
about 40 X 1012 g¢ yr, slightly larger than
that in 1977 and 1978 because of the lower-than-
average runoff in some regions those years.

Mulligan, H. F. 1974. Oceanographic factors
associated with New England red tide blooms.
Proc. of the Ist Int. Conf. Tox. Dino.
Blooms, Mass. Science & Tech. Foundation,
1974, pp. 517-524.

* _ Three red tides during the period from 1972
to 1974 were studied in the coastal region from
Rye, New Hampshire to Cape Ann, Massachusetts.

In addition, from April 1977 to July 1972,
salinities, water temp., transmissivities,

?0-4 and NO-3 profiles and chl. a concentrations
were measured.

Coastal upwellings which bring cysts into
the euphotic zone and provide nutrients were
considered to be crucial in initiating blooms
with subsequent and continuous enrichments con-
tributed by the Merrimack R. important in sus-
taining the bloom. Periods of low rainfall were
found to be especially important as they resulted
in river runoff with high concentrations of
waste which caused a stratified water column.

Munday, J. C. dr. and M.S. Fedosh, 1981. Chesa-
peake Bay plume dynamics from LANDSAT.

p. 79-92. In: Chesapeake Bay Plume Study -
Superflux 1980. NASA Conference Publ. 2188.

J. M. Campbell and J. P. Thomas (Eds.}), 516 pp.
Scientific and Technical Information Branch,
NASA, Washington, DC

Examination of 81 dates of Landsat images with
enhancement and density slicing has shown that the
Chesapeake Bay plume usually frequents the Virginia
coast south of the Bay mouth. Southwestern (com-
pared to northern) winds spread the plume easterly
over a large area. Ebb tide images (compared to
flood tide images) show a more dispersed plume.
Flooding waters produce high turbidity levels over
the shallow northern portion of the Bay mouth.

Munday, J. C., W. Harrison, and W. G. MacIntyre,
1970. Oi? slick motion near Chesapeake Bay
entrance.

Water Resource Bull. Jour. 6:879-884,

148

Murray, $. P. 1975.
wind-driven current near the coast.
Oceanogr, 5:347-360.

Trajectories and speeds of
J. Phys.

Myers, T. D. 1974. An observation of rapid
thermocline formation in the Middle Atlantic
Bight. Estuarine Coastal Mr. Sci. 2(1):75-82.

Thirty-two vertical temperature profiles were
obtained jn the spring of 1973 at an industrial waste
disposal site 60 km off the coast of Delaware.

Initiation of the thermocline occurred rapidly
in mid-April. In a 4-day period, the temperature
at 3m rose from 6.7 to 9.5 C, an average of 0.7
deg. C/day. A discrete warm water front was con-
firmed in surface isotherm plots. Density stratif:
cation was primarily thermally induced.

Nalwalk, A. J., D. F. Paskausky, C. Rathburn,
R. Williams. 1972. Seasonal variation in
temperature and salinity in Block Island Sound.
EOS Trans, Amer. Geophys. Union, 53(4):396.

National Oceanic & Atmospheric Admin. 1976.
Evaluation of proposed sewage sludge dumpsite

areas in the New York Bight apex. Estuarine
Coastal Mar. Sci. 6:93-104.
Naval Weather Service Detachment. 1976. Climatic

study of the near coastal zone - east coast
of the United States. Published by Director,

Naval Oceanography and Meteorology. Wash., DC,
133 pp.
Nelsen, T. A. 1979. Suspended particulate matter

Observations from
NOAA Tech.

in the New York Sight Apex:
April 1974 through January 1975.
Memo. ERL MESA-42. 78 pp.

Nelson, Terry A., Peter E. Gadd and Thomas L. Clarke.
. Wind-induced current flow in the upper
Hudson Shelf Valley. J. Geophy. Res. 83(C12):
6073-6082.

Drawing from wind and current meter data, an
empirical model has been developed for.wind- induced
current flow in the New York Bight apex portion of
the Hudson Shelf Valley. Data have shown that winds
from 270°T (450°), blowing for at least 9 hours at
speeds of greater than 5 m/s, can cause northward
(upchanne?) bottom flow in the shelf valley at
velocities in excess of 40 cm/s. Southern (down-
channel) flow is initiated by winds from’75°T
(435°) blowing for at least 6 hours at speeds of
4 m/s or more. Seasonal variation in the wind
field results in predominant upchannel flow during
October-April with downchannel flow throughout the
rest of the year.


(Fig. 14). The dumpsite is located approximately 106 nm (190 km) southeast
of New York City just off the continental shelf break in depths which range
from about 1,700 to 2,750 m. Over several years, various types of wastes
have been dumped at the 106-Mile site. A few of the wastes, however, make
up a very large percentage of the total which has been discharged there.
These wastes are the duPont Grasselli wastewater (a highly alkaline solu-
tion of magnesium hydroxide), the duPont Edgemoore wastewater (a highly
acidic solution of iron sulfate and iron chloride) and the American
Cyanamid Warner wastewater (a slightly acidic solution of organic residues
from chemical and pesticide production). Because of potential future
dumping needs, two experimental dumps of materials were conducted: the
first in July 1977 of primary sewage sludge from Camden, N.J. and the
second, a test dump of coal ash from a Consolidated Edison coal-fired
power plant, September 1980.

Kohn and Rowe (1977) reported on dispersion experiments of both the
duPont Grasselli wastewater and the American Cyanimid Warner wastewater
conducted in August 1976. Both wastewaters were mixed with a solution
of Rhodamine-WT dye before being discharged. Dispersion in both cases
was measured in water pumped from depths of 5 and 10 m, which were con-
tinuously analyzed with a pair of fluorometers.

Initial dilutions of the duPont Grasselli and American Cyanimid
wastes in the wake of the barge in a calm sea-state differed greatly;
about 4,000:1 and 600:1 respectively. Kohn and Rowe (1977) attribute
these differences in initial mixing to the density of each wastewater rela-
tive to the density of seawater. The duPont waste (1.12 g-cm-3) is denser

than seawater (1.025 g-cm-3) and tended to sink while the American Cyanimid

75


ocean during episodes of strong W-NW winds. Lettau, et al. (1976) prepared
a plot of monthly average air temperatures along the New York and New

Jersey coasts which shows a minimum of about 2°C in January-February and

a maximum of about 25°C in July-August. According to the plot, fall cooling
occurs more rapidly than spring warming, -4.4°C/month vs. +4.0°C/month.
Farther seaward the magnitudes of the minimum and maximum would be moderated,
but the profile of the annual cycle would be very similar. About 100 km

off the New Jersey coast, the January-February minimum is about 4°C and

the July-August maximum is about 25°C. Southward, in the vicinity of
Norfolk, the same distance offshore, the minimum is about 7°C and the maxi-
mum is about 26°C. In the northern portion of our area of interest, in the
Gulf of Maine, minimum average air temperatures are about 0°C and the maximum
js about 18°C (Naval Weather Service Detachment, 1976).

A word of caution regarding the value of summary statements of average
conditions worth noting is that offered by Hopkins and Garfield (1977) as
follows:

"An inherent danger associated with superficial reviews is a

tendency towards oversimplification, thereby giving a false

impression of either the detail required to understand the

system or the system itself. A good example of this tendency

is the use of long term mean conditions to describe a system.

It is now known that these mean conditions likely have no rele-

vance for shorter time periods or often for other equally Jong

periods. Particularly in coastal regions where much of the energy

is found at the 'event' scale (1/2 to 3 days) long term means

represent only a small portion of the total energy. The state of

V


Elsberry, R. L. and R. W. Garwood, Jr. 1978.
Sea-surface temperature anomaly generation
jn relation to atmospheric storms. Bull.
An. Meteorol. Soc., 59:786-789.

* — Anomatous1y high or low sea-surface tempera-
ture patterns are explained by the limiting depth
over which the surface heat flux is distributed.
Atmospheric storms serve to determine the timing
of the transition from a winter regime of deep
isothermal layers to a shallow, summer layer.
Years with early transition dates have high
surface temperature because of the tendency to
accumulate net surface heat flux in a shallow
layer. Years with a late transition date show
lower temperatures as heat addition is spread
over greater depths.

Energy Resources Company. 1981. Demonstration of
compliance of coal ash disposal at the 106-mile
waste disposal site with subparts 8, D and E of
the ocean dumping regulations. Unpublished
report prepared for the Consolidated Edison
Company of New York, Inc. 155 pp.

EPA, 1978. Environmental impact statement on
the ocean dumping of sewage sludge in the
New York Bight - Final - September 1978.
U.S. Environmental Protection Agency,
Region II, 26 Federal Plaza, N.Y., NY 10007.
26 p. plus Appendices A and B.

Fairbanks, R. G. 1981. Isotope measurements
identify sources of Middle Atlantic Bight
water masses. Coastal Oceanogr. Climatol.
News 4(1):6-7.

Fairbanks, Richard G. 1982.
The origin of continental shelf and slope
water in the New York Bight and Gulf of Maine:
Evidence from H2180/Hz160 ratio measurements.
Jour. Geophys. Res. 87(c8)5796-5808.

The H2180/H2160 ratio of meteoric water in
eastern North America decreases with increasing
latitude. The annual weighted average é!0 con-
tent of the Middle Atlantic Bight (MAB) and
Gulf of Maine (GOM) rivers are -9.33% and -10.89%,
respectively. The 6 "O compositions of the major
east coast rivers are 2% enriched during summer
months. By using H21€0 and salinity measurements,
both conservative properties of sea water, the
geographic origin of continental shelf water
can be identified. The isotope-salinity tracer
method, which has been used so successfully in
polar regions, is also an effective method in
the temperate MAB because subpolar waters are
exported to this region,, The apparent dilutent
of slope water is -22%5'°0 relative to standard
mean ocean water. Water of this composition
is presently forming in the Labrador Sea. Melt
water fron sea ice has nearly the sane isotopic
composition as the sea water from which it
formed and thus may be distinguished from
meteoric water, In March 1977, the New York
Bight cold pool contained as much as 2.5% sea
ice melt water. The Gulf of St. Lawrence is
the nearest source of sea ice. The New York
Bight ‘cold pool' was renewed from the north
between March and July, which was the extent
of our sampling period.

12k

Falk, L. L. and J. R. Gibson. 1977.
of release time for ocean disposed waste waters.
Unpubl. Rep. submitted to U.S. E.P.A. Region II.
Edison, New Jersey. 38 pp.

Falkowski, P. G., T. S. Hopkins and J, J. Walsh,
1980. An analysis of factors affecting
oxygen depletion in the New York Bight.

J. Mar. Res. 38(3):479-506.

* — This article is an analysis of possible
factors leading to oxygen depletion within the
New York Bight based on historical data extending
back to 1910. The Ceratium tripos bloom of 1976
is given particular attention. Factors leading
to its establishment and subsequent shel] fish
kill are said to be a warm winter with large
runoff, a low frequency of spring storms, a

deep sunmer thermocline, persistent southerly
winds with few reversals, a larae autochtonous
carbon load and low arazing pressure by zoop]ank-
ton. It is suggested that anoxia could have
occurred due to this abnormal chain of biological
events without any sludge dumping from New York
City.

Fedosh, M. S. and J. C. Munday. 1982, Satellite
analysis of estuarine plume behavior. VIMS
Contr. No. 1066 6pp. Prepared for inclusion
in the proceedings of OCEANS 82, IEEE, Wash-
‘ington, D.C., September 20-22, 1982.

Estuarine plumes at the Chesapeake, Delaware,
and Raritan Bay entrances were studied in 268 Land-
sat MSS and 68 HCMM thermal infrared images. Tur-
bidity or thermal boundaries were detected in
nearly all images. Wind had a large influence on
locations of boundaries: under strong southwest
to west winds, plumes moved eastward from bay
mouths into waste disposal areas. Northern winds,
the Cariolis force, and net non-tidal coastal
currents drove plumes southward along the coasts
from bay mouths. Plume boundaries are more dis-
persed during ebb tide. Seasonal effects are
mixed.

Firing, E. and R. C. Beardsley. 1976. The
behavior of a barotropic eddy on a g-plane.
J. Phys. Oceanogr. 6(1):57-65.

Fischer, H. B. 1980. Mixing processes on the
Atlantic continental shelf, Cape Cod to
Cape Hatteras. Limnol. Oceanogr. 25(1):
114-125.

Data from moored current meters and airborne
and satellite observations are used in conjunction
with analyses of shear flow dispersion to estimate
the dispersion of dissolved substances in the
Middle Atlantic Bight during unstratified periods.
The long-shelf dispersion coefficient is
estimated to be of the order of 10'-10% cm?-s-2,
and the cross-shelf dispersion coefficient of
the order of 3 x 10° cm*.s-? at midshelf.

The cross-shelf estimate is a factor of 10 less
than previous ones, which were based on the
assumption that the cross-shelf flux of fresh-
water is equal to the inflow from tributary
rivers within the bight itself.

The determination


Han, G., D. V. Hansen and J. A. Galt. 1980.
Steady-state diagnostic model of the New York

Bight. J. Phys. Oceanog. 10(12):1998-2020.

A qualitative evaluation is made of the output
froma finite-element, steady-state diagnostic
model to observed time-averaged currents. The mode7
uses a vorticity balance equation with linear bottom
friction and inputs observations of near-bottom
currents on the mode! boundary, density field and
bottom topography. The output is the near-bottom
(barotropic) velocity field over the entire modeled
region, Velocity profiles are constructed using
the thermal wind equation with the observed density
field from May 1976 and a turbuTent closure scheme
model of Mellow and Durbin to reproduce the top and
bottom Ekman layers. Transport is computed in
Jayers above and below the pycnocline by integrating
the geostrophic velocity profile and adding the
Ekman layer transport.

Comparisons of the modeled bottom velocities
at three moorings interior to the region and
modeled vertical profiles of velocity at the interior
moorings and the four boundary moorings to the ob-
servations at these points, show favorable agreement.
Along-isobath flow is modeled more accurately than
cross-isobath flow. Along-isobath flows, both in
the shelf valley and outside the valley, are well
represented, but near-bottom flows in the valley
in two of the patterns are strongly ageostrophic
and thus are not in agreement with model results.
Errors > 100% are found for weak flow events and
the accuracy of the vertical shear in the velocity
deteriorates away from the time of the density
observations.

The mode? results are useful for calculating
the advective transport of dissolved and suspended
constituents in the water. Though the accuracy of
the point velocities have a median relative error
of--50%, the transport calculation is probably more
accurate,

Han, G. C. and D. A. Mayer. 1981. Current
structure on the Long Island inner shelf.
J. Geophys. Res. 86:4205-4214,

Current velocity records from a deployment
of 17 current meters across a ridge and swale
topography with a 5 m amplitude, 6.5 km off the
coast of Long Island, were analyzed to determine
the interaction between the flow field and the
topography which might maintain these special
bottom features. No first-order interactions
were found; the flow field was generally
parallel everywhere. Correlation, coherence,
and empirical orthogonal modal (E0M) analysis
showed no significant differences between meters
as a function of alongshore or cross-shore
separation. EOM analysis showed that 79% of
the variance was in the first barotropic mode
with a strona vertical shear that was probably
related to friction. Tide and wind response
models can replicate about 64% of the variance
in the alongshore velocity, of which about
30-40% is tidal. The residual record, uncor-
related to wind or tide, shows the effect of
alonashore variations in the pressure field
following a storm event by reversing the flow
opposite to the diminishing wind stress. By
regression of the averaged alongshore bottom
velocities to wind stress, a linear bottom
friction coefficient of 0.14 cm sl is found,
which is in agreement with previous estimates,
and a time average alongshore pressure gradient
of 0.3 X 10-7 is found which is an order of
magnitude smaller than previous estimates. By
scaling the results of the wind response model,
the linear bottom friction coefficient is also
found to be 0.14 cm s-1.

130

Han, G. and T. Niedrauer. 1981. Hydrographic
observations and mixing processes in the New
York Bight, 1975-1977. Limnol. Oceanogr.
26(6):1126-1141.

A series of 15 hydrographic cruises in the New
York Bight over 1975-1977 is described and analyzed.
The cruises cover all seasons but focus primarily

on spring and summer. Temperature and salinity data
show wide seasonal and interannual variability.

Each of the three regions - inner bight, midshelf,

and outer shelf slope - has distinctive properties
and dynamics.

The inner bight properties are affected primarily
by river flow and wind-driven flows up the shelf
valley which often splits the freshwater surface
layer into two plumes, one east and one west of the
valley head. The "cold pool" temperature structure
on the midshelf is different each year. The water
with the lowest recorded temperature (2.58°C) was
on the bottom after the thermocline formation in
May 1977.

Mixing models of the inner bight confirmed pre-
Vious estimates of pesigence time as 6.8 days and
yielded Ky - 5 X 108 cmé-s~! with an advective trans-
port component of 1 cm-s-! to the southwest. A model
of the mixing of the lower layer cold pool on the
midshelf with onshore, offshore, and upper layer
waters yields Ky = 7 X 108 and K, = 0.1 cm@-s-! as
the on-offshore horizontal and vértical diffusion
coefficients.

Hansen, D. V. 1970. Gulf Stream meanders
between Cape Hatteras and the Grand Banks.
Deep-Sea Res. 17(3):495-511.

The position of the Gulf Stream between
Cape Hatteras and approximately 60°W was
delineated at intervals of a few days to month
using the 15°C isotherm at 200 m depth as an
indicator for the thermal front associated with
the stream. The dominant pattern inferred from
the sequence of observations is a quasi-geostrophic
wave pattern of 200-400 km wave length moving to
the east with phase speeds of 5-10 cm/sec, and
amplitudes generally increasing steadily to the
east, except for a breakdown in summer when
very large amplitude meandering between 69°W and
64°W led to extremely complicated thermal
conditions in this region.

Evaluation of topographic and Coriolis
effect variations along the paths indicates
that for plausible current structure the mean
path of the stream is consistent with the
topographic control hypothesis advanced by
Warren (1963). Although the meanders too must
be strongly influenced by topographic variations,
these variations are in general insufficient
to account for the curvature of meanders in
the observed paths.

Comparison of unstable wave properties
inferred from the observations with results
from several investigations of dynamic instabil-
ity as a possible cause of the meanders shows
that baroclinic instability theories yield
qood estimates of wave length of the fastest
growing wave component, and a baroclinic theory
with some topographic influences yields a good
approximation to the phase speed as well. An
equivalent spatial growth rate computed from
the disturbance group velocity and the temporal
growth predicted by all the theories is genera}-
ly larger than that of the observed meanders.


with different wind conditions the offshore retreat of bottom water.
Field studies with sea bed drifters and bottom current meters (Bumpus,
1965; Charnell and Mayer, 1975; Patchen et al., 1976; Hardy et al., 1976;
and Hansen, 1977) indicate the existence of a clockwise gyre in the Bight
apex. However, this feature has not yet been described synoptically,
and the forcing functions involved or the resulting variations in the
gyre have not been defined. During the passage of "northeaster" storms,
current speeds greater than 30 cm-sec~! (0.6 knot) in the surface layer
and greater than 25 cm:secTM! (0.5 knot) in the bottom water have been
recorded.

Tidal currents measured within 3 m of the bottom near the 12 mile
dumpsite (Hansen, 1977) ranged up to about 10 cm-sec-! (0.2 knot). Accord-
ing to EPA (1978), "Bottom tidal current velocities may be low, about
10 cm:secu! (4 in/sec), but when coupled with wind-driven currents during
storms, they can cause resuspension and subsequent redistribution of
sediments."

Numerous studies of municipal sewage sludge dumping at the 12-mile
site and the impacts of such dumping have been made over a period of
several years. However, specific studies of dispersion of sewage sludge
at the site have been relatively few. Callaway et al. (1976) conducted
some preliminary measurements of sludge dispersion at the site, including
measuring physical characteristics such as bulk density, solids density
and particle size, followed by an at-sea multi-parameter study of each
sludge type after dumping. Their measurements showed that density of
solids was always greater than seawater. Bulk density, however, was
found to be always less than seawater at the 12 mile site. This was
observed to limit mixing of the largest fraction of the dumped sludges

to the upper portion of the water column both during underway and stationary

70


45° i

100 FM

! |
9-10 NOV ‘81 y ~ C/

40°)

35°

45°

40°

35°

Figure 6. The birth of warm core ring (WE) from a Gulf Stream meander at about
39°N, 63°W. From weekly oceanographic analysis charts produced
jointly by the National Weather Service and National Earth Satellite
Service of NOAA. 28


°ep

“seaue Bul_lamdn pue sownid quan, jsa auluenysa jSoW SapnyduL YOLYM pueg aAL}Oe | eySeOD Jo AuepuNog
azyeuLxoudde sapeoLpul aul, JOP -yseq ‘aWlz ILyLoads Aue ye sawnid ayy yuaeseudeu you op ynq ‘sawLy
snoLueA je padouan{jul suoiHar azeulxoudde ayy azed1pul Seaue papeys ‘*sawn{d quan, jya auLvenysy “Gl aunbLy

"Os . "on "Bp <n °Qq "So on
Z Z LN NN an .

oh,

99


FRONTS

Where two water masses in the ocean meet, there is frequently a front,
across which there is a sharp transition between the differing character-
istics of the two water masses. Typically, major advective exchange
between the water masses is restricted and occurs only sporadically
across fronts. Frontal regions are commonly convergence zones, and con-
sequently floating or suspended materials including pollutants, in the
water tend to become concentrated along them. Pollutants accumulated
in this fashion would be located in close association with increased
biological abundance and activity, which quickly develops in the vicinity

of a convergence zone.

Shel f-Slope Front

The shelf-slope front is located over or near the outer edge of
the continental shelf, separating less saline and usually cooler shelf
water from the slope water which lies offshore. The front is continuous
from Cape Hatteras to Georges Bank and is present throughout the year.
The shelf-slope front extends from the surface to the bottom, typically
touching bottom at depths between 75 and 100 m and slopes seaward,
with the surface intersection situated about 25 to 55 km offshore from
the bottom contact (Beardsley and Flagg, 1976).

The horizontal salinity gradient across the shelf-slope front is
typically 1 to 2 0/oo over 10 to 50 km and near-bottom temperature
gradients are about 2-4°C throughout the year, but can be as much as
8°C (Bowman and Wunderlich, 1977). Temperature contrasts across the
front at the surface normally are about 4° to 6°C, but are much less

intense from late June to September as the summer thermocline and a warm

35


Smith, R. A., J. R. Slack, and R. K. Davis. 1976b.
An oilspill risk analysis for the North Atlantic
outer continental shelf lease area. U.S. Geol.
Survey Open File Report 76-620.

An oilspill risk analysis was conducted to
determine relative environmental hazards of develop-
ing oi1 in different regions of the North Atlantic
Outer Continental Shelf lease area. The study
analyzed probability of spill occurrence, likely
path of pollutants from spills, and locations in
space and time of recreational and biological
resources likely to be vulnerable. These results
are combined to yield estimates. of the overall
ojlspill risk associated with development of the
lease area.

Spaulding M. 1981. Oi] spill fishery interaction
modeling - application to Georges Bank. Paper
presented at Middle Atlantic Bight Physical
Oceanography Workshop, Univ. Rhode Island,
October 21-22, 1981.

Spaulding, M. L. and R. Robertson, 1981. Three
dimensional numerical dispersion model of
acid iron waste disposal. P, 133 (abstract)
in: Program and Abstracts - Third Inter-
national Ocean Disposal Symposium. Woods
Hole Oceanographic Inst., Woods Hole, MA
October 12-16, 1981. 156 pp.

Stearns, F. 1965. Sea-surface temperature
anomaly study of records from Atlantic Coast
stations. J. Geophys. Res. 70:283-296.

Stearns, F. 1969. Bathymetric maps and geo-
morphology of the Middle Atlantic continental
shelf. Fish. Bull. 68:37-66.

* "The shape of the sea floor can influence
the movement of water masses on the shelf, and
this movement can affect the distribution of such
Oceanographic properties as temperature, salinity,
and nutrient elements."

Stefansson, U., L. P. Atkinson, and D. F. Bumpus.
1971, Hydroaraphic proverties and circula-
tion of the North Carolina Shelf and Slope
Waters. Deep-Sea Res. 18:383-420.

Stefansson, U., and L. P. Atkinson. 1977.
Nutrient-density relationships in the
western North Atlantic between Cape Lookout.
and Bermuda. Limnol, Oceanogr, 16(1):

-57.

Steimle, F. W. and C. J. Sindermann. 1978.
Review of oxygen depletion and associated
mass mortalities of shellfish in the Middle
Atlantic Bight in 1976. Mar. Fish. Rev.
40(12):17-26.

160

Steimle, F. W. and R. B. Starr. 1979. Chapter 2.
Temporal development of physical characteristics.
In: Oxygen Depletion and Associated Benthic
Mortalities in New York Bight, 1976. NOAA
Prof. Paper 11. R. W. Swanson and C. J. Sinder-
mann (Eds.). pp. 17-50.

* Data from expanded water column characteriza-
tion (XWCC 8, 9, 10) cruises on NOAA ship George
Kelez and Researcher are objectively analyzed-—
Physical oceanographic conditions of water column

and associated dissolved oxygen levels for April,

May, June and September 1976, are defined.
Specifically, seasonal temperature, salinity, density,
pycnocline, dissolved oxygen (upper and Tower levels),
and Hurricane Belle X8T data are studied and con-
clusions drawn for the 1976 oxygen depletion event

in the New York Bight.

Steinhauer, W. G. 1976. Transport pathways of
polychlorinated biphenyls in Atlantic
water. J. Mar. Res. 34(4):561-575.

* Data from seven separate cruises between 36°S
and 54°N during 1973-1975 were analyzed for PCB
content. The PCB appears to concentrate in regions
of high precipitation, verifying transport from the
land via vapor-aerosol. The authors arque from the
data that there is net northward transport of PCB
in surface waters with entrainment in North Atlantic
deep water and subsequent re-transport southward

at depths.

Stewart, H. B. , dr. and G. F. Gordon. 1964.
Underwater sand ridges on Georges Shoal.
P. 102-114. In: Papers in Marine Geology.
R. L. Miller (Ed.). MacMillan Co., N.Y.
531 pp.

Stigebrandt, Anders. 1980. Cross thermocline low
on continental shelves and the location of shelf
fronts. Elsevier Scientific Publishing Co.,
New York, 1981. pp. 51-65.

The author presents a model of 2 layered water
column in shelf waters with a one-dimensional thermo-
cline. The solution for his model indicates that
tidally driven turbulence in the lower layer affects
the upper layer in regions beyond frontal local areas
and there is water exchange even in the presence of
a thermocline. Author states that knowledge of bottom
tidal currents, winds, and heat exchange through the
sea surface should allow calculation of exchange
rates through the thermocline.

Stommel, H. 1966. The Gulf Stream. “University of
Calif. Press, Berkeley, California, 248 p.

Stommel, H. and A. Leetmaa.
‘on the continental shelf.
Sci. 69(11):3380-3384,

1972. Circulation
Proc. Nat. Acad.

Stubblefield, W. L. 1976. Morphologic evolution
and coastal sand transport, New York - New
Jersey shelf. In: Special Symposia Vol. 2,
Middle Atlantic Continental Shelf and the
New York Bight, M. G, Gross (Ed.). Amer.
Soc. Limnol. Oceanogr. p. 69-89.


of hypoxia developed off New Jersey, 1976 summer dissolved oxygen con-
centrations off Long Island were also well below normal and were probably
reduced in adjacent areas (Armstrong, 1979). Because of the similarity
of conditions in the bottom waters throughout the Middle Atlantic Bight,
a combination of factors could lead to hypoxia most anywhere in this
region, although they tend to be most critically focused for the waters

off northern New Jersey.
BOTTOM CURRENTS AND SEDIMENT TRANSPORT

Solid wastes with densities greater than sea water will accumulate
on the sea floor, provided bottom currents are not strong enough to resus-
pend them. On most of the continental shelf, bottom currents are strong
enough to resuspend any solids less dense than sand and transport them
considerable distances. Waste particles less dense than sand dumped in
such areas would be scattered widely, and only temporarily deposited in
areas of ridge-and-swale bottom topography. Wastes with about the same
density and grain size as sand would be moved along with sand waves which

are common in many areas of the shelf.

Georges Bank

The mean circulation pattern on Georges Bank is a general clockwise
motion with speeds of 15-20 cm-secTM! on the northern side of the bank and
a broad southwestward flow of about 5 cm-sec-! along the southern side.
The water motions, however, on both Georges Bank and Nantucket Shoals are

dominated by strong tidal currents that are often in excess of 70 cm-sec-l.

60



Mahoney, J. B. 1979.
Plankton dynamics and nutrient cycling.

Part 2 - Bloom decomposition, Chap.9. In:

Oxygen depletion and associated benthic
mortalities in New York Bight. 1976.

R. L. Swanson and C. J. Sindermann (Eds.).

NOAA Prof. Pap. No. 11, U.S. Dept. of
Conm., Rockville, MD

Malone, T. C. 1976.
Phytoplankton productivity in the apex of
the New York Bight: Environmental reg-
ulation of productivity/chlorophy!1 a.
Am, Soc. Limol. Oceanogr. Spec. Symp.
2:260-272.

Malone, T. C., W. Esais, and P. Falkowski.
1979,

Plankton dynamics and nutrient cycling,
Part I - Water colum processes. Chap.
9 In: Oxygen depletion and associated
benthic mortalities in New York Bight,
1976. R. L. Swanson and C. J. Sindermann
eds. NOAA Prof. Pap. No. 11. U.S. Dept.
Commerce, Rockville, Maryland.

Mannheim, F. T., R. H. Meade and G. C. Bond.
1970. Suspended matter jn surface waters
of the Atlantic continental margin from
Cape Cod to the Florida Keys. Science
167:371-376.

Maul, G. A., P. W. deWitt, A. Yanaway, and
S..R. Baig. 1978. Geostationary satel-
lite observations of Gulf Stream meanders:
Infrared measurements and time-series
analysis. J. Geophys. Res. 83(C12):
6123-6135.

Maurer, D, 1982. Review of benthic inverte-
brates of Georges Bank in relation to
gas and oi] exploration with emphasis
on management implications. Unpublished
report submitted to NOAA/NMFS/NEFC, Woods
Hole, MA

Mayer, D. A. and G. C. Han. In press.
Circulation in the Hudson Shelf
Valley, Part I. J. Geophys. Res.

14h

Mayer, D. A., D. V. Hansen, and D. A. Ortman.

1979. Long-term current and temperature ob-
servations on the Middle Atlantic Shelf.
J. Geophys. Res. 84(C4):1776-1792.

Nearly 2200 days of current and temperature
data were collected at a midshelf location in the
Middle Atlantic Bight between June 1974 and March
1977. These data were examined for the average
conditions and seasonal cycles of water circu-
lation and temperature and some statistical
properties of their variation at higher fre-
quency. The average flow is found to be toward
the south-southwest at about 5 cm/s near the
surface, diminishing to about 1 cm/s near the
bottom. The occurrence of energetic wind-driven
transient current events which can exceed a 2-
month duration makes it impossible to determine
a clear seasonal pattern in the sequence of
monthly mean flows. There is, however, a clear
seasonal pattern in the distribution of higher-
frequency fluctuations. Storm wind-induced
transient currents of 3- to 10-day duration
appear prominently in winter records. Inertial
currents appear selectively in the summer,
that is, in parts of the water column welt
insulated from the bottom by a strong thermocline.
For iow-frequency motions (periods from 3 to 10
days) in both summer and winter records the
preferred directions of motion throughout the
water column appear to be consistent with equili-
brium (mean) Ekman veering arguments. The
water column response was found also to be most
sensitive to the component of wind stress parallel
to the bathymetry. The temperature follows a
well-known Seasonal cycle of heating and stratifi-
cation. Ouring the unstratified seasons, very
little high-frequency temperature variation is
observed, but during summer, thermal oscillations
due to daily heating and inertial and semidaily
tidal frequencies (3/3, 4/3, and 6/3 cpd) and a
5/3-cpd oscillation appear prominently.

Mayer, D. A., D. V, Hansen, and S. M. Minten. 1979.
Water movement on the New Jersey shelf, 1975
and 1976. In: Oxygen Depletion and associated
Benthic Mortalities in New York Bight, 1976
Swanson, R. L. and C. J. Sindermann (eds).
NOAA Prof. Pap. 11, pp. 149-163.


50

100

150

200

i = ! 1 | 1 i

Figure 7, Injection of warm slope water, possibly mixed with Gulf
Stream water, onto the continenta] shelf by the circulation
of warm core ring 77-1, as revealed by an XBT temperature
(°C) section conducted on 2 November 1977 along the 71°W
meridian across the continental shelf. From Crist and
Chamberlin, 1979. Inset chart shows location of temperature
section and warm core ring 77-I.

31


in four water depths between 59 and 143 m were being reworked based on
ripple marks and sedimentary structure analyses. Mean currents varied
between 11.8 and 19.5 cm.sec-! measured at1.5-2.0m off the bottom. Based
on critical erosion velocities, he determined that the shelf sediment may
be eroded and transported as much as 30% of the time by currents and
eroded 8% of the time by wind waves at 30 m depth. Freeland et al.

(1976) discussed similar results for linear bedforms indicating sand
movement.

Swift et al. (1976) showed the importance of storm events in causing
large sediment transports with sustained southwestward near-bottom currents
of greater than 50 om-sec”! for approximately 12 hours. These short,
efficient, storm-related, large scale transports are separated by longer
periods of quiescent minimal transport. Data indicated westward transport
off Long Island and southward transport off the New Jersey shore.

Two large depositional areas are located within the Middle Atlantic
Bight and are quite different from the more common shelf relict ridge
and swale topographies discussed by Swift et al. (1976)and Freeland et al.
(1976). One of these areas is the so-called Christiaensen Basin located
within the apex of New York Bight. This topographic low has much higher
levels of clay and silt than surrounding sand areas. Although the sewage
sludge (12 mile) dumpsite is located near the Christiaensen Basin, the
Basin has not shown any measurable bathymetric changes which could be
attributed to dumping of sludge (Freeland et al., 1976). The area outside
of the Christiaensen Basin also contains a few mud-sand scour patches
with linear bedforms indicating sand movement. The Christiaensen Basin
may act as a "sediment trap", trapping fine sediments which are only

aperiodically resuspended by major storm events.

63


°ep

“seaue Bulj amdn pue seawnyd
quan,gga auLuenysa 7SoW SepnfouL YOLYM pueg aALZIEe [eyseod yo Auepunog azeuLXoudde sazeoLpuL UL

jop-yseq “weak ay Jo qued yseay 7e Bul_Lamdn oq yoafqns asoyz ae seaue papeys “Sease Hull, [amd “g{ aunbLy
°On "On "Bn S, °9, °$, “op
& ce co
_L Z aN NL vA XN .
oon

100


Tingle, A. G. and D. A. Dieterle. 1977. A
numerical oi1 trajectory forecast model
used to assess the hazard to Long Island
beaches fron oi] entering the New. York
Bight apex from February 11-24, 1977.
BNL 50649. Brookhaven Nat. Laboratory,
Upton, NY -11973.

Oi] spilling into the Hudson River from a
grounded barge (carrying 400,000 gallons) was
observed entering the N.Y. Bight Apex on
11 February 1977. A computer model was used
to forecast the subsequent trajectory of this
oil and to assess the hazard to Long Island
beaches. O11 was forecast to wash ashore on the
13th on Rockaway or Long Beach, depending upon
the initial position of the oil in the bight.
Of1 was observed on Rockaway Beach on the 13th.
Additional daily forecasts indicated no further
hazard to Long Island, also in accordance with
observations, and the forecasts were terminated
on the 16th. The model was also used to assess
a beaching event that occurred a week Tater.

The complete calculations are available on
microfiche in graphics format.

Twichel1, D. C., C. E. McClennen, and B. Butman.
1981. Morphology and processes associated
with the accumulation of the fine-grained
sediment deposit on the southern New
England Shelf. J. Sedim, Petrol. 15(1):
269-280.

Uchupi, E. 1967. Slumping on the continental
margin southeast of Long Island, New York.
Deep-Sea Res. 14:635-639.

U.S. Naval Oceanographic Office. 1963. Oceanographic
Atlas of the North Atlantic Ocean - Pub. No. 700,
Section IV, Sea and Swell. Wash., DC, 227 pp.

Vincent, C. £., 0, J. P. Swift and B. Hillard.
1981. Sediment transport in the New York
Bight, North American Atlantic shelf.

In: Sedimentary Dynamics of Continental
Shelves, C. £. Nittrouer (Ed.), Elsevier,
New York, pp. 369-398.

163

Vincent, C. E., R. A. Young and D. J. P. Swift.
1982. On the relationship between bedioad
and suspended sand transport on the inner shelf,
Long Island, New York. J.. Geophys. Res.
87(C6) 24163-4170.

Data obtained by a near-bottom Profiling Concen-
tration and Velocity system (PCV), deployed in 10 m
water depth at a site 1 km from the Long Island
coastline, are used to examine links between bed-
Toad and suspended sand concentrations. Calcula~
tions of bedload areal concentration C* are based
on the empirical results of Vincent et al. (1981)
and use the theoretical formulations of Grant and
Madsen (1978, 1979) to describe the interaction
between wave and current boundary layers. Sus-
pended sand concentrations were obtained directly
from an Acoustic Concentration Meter (ACM).
Average suspended sand profiles Cz were found to
fit closely to @ Inq-linear protife Cz =Cl(1-A
loge z/z')swhere Ci is the sand concentration at
a height z1=1 om fron the bed and A is empirically
determined as 0.22 + 0.005. A linear correlation
is observed between the areal bedload concentra-
tion C* (the volume of bedload per unit area of the
bed) and the suspended sand concentration 1 cm
above the bed C1, with a coefficient of 0.82
(significant at the 1% level), and supports the
hypothesis of Einstein (1950) that bedload and
suspended load are related through bedload concen-
tration. It is also shown that the sedment thres-
hold criterion of Komar and Miller (1973), when
expressed as a ratio (here called the Komar ratio),
can be used as a useful predictor for C1 under
conditions where the wave orbital currents are
much greater than the mean flow. These relation-
ships offer the opportunity for the calculation
of both bedload and suspended sand transport
rates from measurements of the steady current
velocity and wave parameters, combined with in-
formation defining the surficial sediments and
local bottom topography.

Voorhis, A. D., D. C. Webb and R. C. Millard.
1976. Current structure and mixing in the
shelf/slope water front south of New England.
d, Geophys. Res. 81(21):3695-3708.

Horizontal and vertical currents in the front
along the edge of the continental shelf south of
New England during the late spring were measured
by tracking special neutrally buoyant floats
which tagged different water masses. The mean
current (10-20 cm s-!} was westward along the
shelf and was confined completely to the overlying
shelf water with a geostrophic transport of
about 0.7 sverdrups between the 80- and 300-m
jsobaths. No mean cross-shelf or vertical
currents could be reliably measured. Higher-
frequency currents were detected and are described.
Numerous conductivity-temperature-depth lowerings
were made over the drifting floats to examine
the interleaving process and possible mixing
between shelf water and slope water. The layers
are thinned by vertical shear, and they gain
and lose both heat and salt on a time scale of
1-3 days. This plus the rich microstructure
suggests the existence of vertical turbulent
exchange between layers having,a turbulent
diffusivity of the order of cm@s. Estimates
of net annual heat and salt input to the shelf
are made, and they appear to be significant in
determining the heat and salt budget of’ the
shelf water mass.


Csanady, G. T. 1981B. Circulation in the coastal
ocean. Part 2. Trans. Am. Geophys. Union,
EOS, vol. 62(5) Feb. 3, 1981.

* As a continuation of part 1, current driving
forces unrelated to winds are examined. Flow
Phenomena observed are: Current reversals and
dynamic principles that govern the propagation
of relevant types of trapped waves that occur
cyclonically southwestward down the coast of
North America, flow controlled by bottom friction
and dynamics is considered, and also thermohaline
circulations caused by cooling of shallow waters.

Csanady, G. T. 1981C. Circulation in the coastal
ocean, Part 3. Trans. An. Geophys. Union.
£0S, Vol. 62(8), Feb. 24, 1981. :

* The simple dynamic shelf circulation models
from parts 1 and 2 are broadened to focus on
long-term, larger-scale flow phenomena in the
layer model.

Csanady, G. T. 1981D, Analysis of dumpiste
diffusion experiments. In: Ocean Oumping
of Industrial Wastes. 8. J. Ketchum, D. .
Kester and P. K. Park (eds). p. 109-129.
Plenum Press, N. Y. and London, 525 pp.

The oceanic dispersion of industrial waste
barged to Deep Water Dumpsite 106 is effected
in the first instance by barge-bound eddies
("wake dispersion"), then by naturally occurring
mean shear and turbulence. Wake dispersion is
very efficient, producing initial dilution up
to a factor of 104, and is controlled by the
dimensions and the forward speed of the barge.
Subsequent dispersion by natural oceanic pro-
cesses is slow under stratified summer condi-
tions, describable by an effective diffusivity
of order 300 cm? sec-! or a diffusion velocity
in the beighborhood of 0.2 cm sec~’, for the
first 12 hours or so after release. A com-
parison of the observed data with shear-dis-
persion theory shows that: (a) horizontal
dispersion in the upper 10-20 m of a strati-
fied ocean is mainly due to mean shear-ver-
tical mixing interaction; (b) the low ob-
served rates of dispersion may be attributed
to the fact that an early phase of shear diffu-
sion was in evidence. Extrapolation to
diffusion times of the order of several days
should be possible using a constant diffusion
velocity, or an effective diffusivity increasing
in direct proportion to time.

Csanady, G. T. 1981E. Long-term fate of barged waste
in slopewater, P, 123-124 (abstract). In:
Program and Abstracts - Third International Ocean
Disposal Symposium. Woods Hole Oceanographic
Tastitution, Woods Hole, Mass. Oct. 12-16, 1981.

56 pp.

Csanady, G., 6. Flierl, D. karl, D. Kester,
T.'0'Connor, P: Ortner, W. Philpot. 1979.
Deepwater Dumpsite 106. In: Assimilative
capacity of the U.S. Coastal Waters for
Pollutants. Proceedings of a workshop at
Crystal Mountain, Washington, July 1979.
E. D. Goldberg, (Ed.) National Oceanic
& Atmospheric Administration, Boulder,
Colorado.

122

Davis, C. W. 1979, Bottom water temperature trends
in the Middle Atlantic Bight during spring
and autumn, 1964-76. NOAA Spec. Sci. Report -
Fish. NOAA Tech. Rep. NMFS SSRF 739, 13 p.

Day, C. G. 1957. Drift bottle records for Gulf of
Maine and Georges Bank, 1931-56. Spec. Sci.
Rep.: Fisheries No. 242.

Day, C. G. 1958. Surface circulation in the Gulf of
Maine as deduced from drift bottles. U.S. Fish
and Wildl, Serv., Fish, Bull. 141:443-472.

Diaz, H. F. 1979. Chapter 3. Atmospheric conditions
and comparison with past records. In: Oxygen
Depletion and Associated Benthic Mortalities in
New York Bight, 1976. Swanson, R. L. and C. J.
Sindermann (Eds.), NOAA Prof. Paper 11, pp. 51-77.

* An objective comparative analysis from climatologi-
cal data and relevant atmospheric forcing fields for
February-August 1976 is made in this paper. The magni-
tude and persistence of anomalous weather patterns
during the months preceding the period of bottom-water
anoxia suggest a possible connection to the disruption
of the marine environment. Anomalies existing in sea
surface temperature, surface wind, wind stress and
vertical motion calculations consisting of open-ocean
and coastal upwelling estimates are examined.

Dickson, R. R. and J. Namias. 1976. Atmospheric
climatology and its effect on sea-surface
temperature. In: The Environment of the
United States Living Marine Resources, 1974.
MARMAP Contribution No. 104, pp. 3-1 to 3-12.

Dickson, R. R. and J. Namias, 1976. North American influ-
ences on the circulation and climate of the North
Atlantic sector. ‘Mon. Weather Rev. 104:1255-1265.

During the post-war period the pressure field at
Greenland has been characterized by long-sustained

winter regimes of alternating high and low pressure, with
important effects on the winter climate of Europe.
Although these alternations of pressure anomaly at
Greenland may be shown to be associated with periods

when the pattern of long waves in the upper westerlies
showed a general reversal over much of the: Northern
Hemisphere, it is also suggested that within this hemis-
pheric pattern of change, contemporary variations of
winter climate along the Atlantic seaboard of North
Anerica have exerted an important influence on the
pressure field at Greenland and,- through teleconnections,
elsewhere (e.g, the North Atlantic and Europe). Con-
paring months of extreme winter warmth and cold over the
southeastern United States it is shown that changes in
the strength of the baroclinic field at the coast are
associated with major changes in the distribution of
winter storms. More specifically, during winters of
extreme cold over the southeastern United States and

the associated enhanced baroclinicity at the Atlantic sea-
board, the zone of peak winter storm frequency js

drawn far to the southwest of normal, with @ corresponding
decrease in cyclonic activity in the Iceland-Greenland
area.


Central Georges Bank Front

Over the central portion of Georges Bank, in depths less than approxi-
mately 40-60 m, the water is well-mixed throughout the year and as a result
is seasonally separated from deeper water by a front. The water enclosed
by this front is approximately equal to that defined as Georges Bank Water
by Hopkins and Garfield (1981), which they say owes its unique character-
istics to isolation and low volume replenishment. The mechanism causing
the front is identical to that for Nantucket Shoals, tidal stirring over-
comes the stabilizing tendency of solar heating. During winter the increased
wind stress extends the mixed water column out to the shelf-slope front
on the south side and into the Gulf of Maine. In spring, as wind stess
decreases and solar heating increases, the front forms at approximately
the 60 m isobath around the bank. On the north side of the bank this is
near the shelf break and creates a temperature front separating the rela-
tively warm stratified waters near the surface in the Gulf of Maine from
the cooler isothermal waters on Georges Bank. On the south side of the
bank, however, the distance between the 60 m isobath and the shelf break
(200 m) is relatively long, about 75 km, and as the season progresses the
thermocline develops over the outer shelf and slope, separating the water
below the thermocline from the heating source. This creates a seasonal cold
pool between the tidally generated front on the south side of Georges Bank
and the shelf-slope front.

The position of the front varies with the phase of the tide, moving
north during flood and south during ebb. There is some variation with the
spring-neap (fortnightly) cycle but less than would be expected. This
has been discussed by Simpson and Bowers (1981) and attributed to variable

efficiency of mixing in the cycle.

41


use the calculated values from it to drive the diagnostic model. This
is similar to the technique of using a coarse grid model to determine
boundary conditions for fine grid model.

The diagnostic model is a useful framework for retrospective analysis
of a field program. This information could then be used to indicate a
more efficient deployment/arrangement of field instruments to maximize
the return of information for a given number of instruments. In fact,
part of the retrospective analysis of a field program could determine the
sensitivity of the calculated currents to various subsets of the actual

measurements.

Box Model for Middle Atlantic Bight Transport

The box model technique is based on the concept of mass conservation.
It is assumed that the area to be modeled is a well-mixed reactor, and
conservation equations are written for the box. By writing equations
for various independent tracers, enough equations can be obtained to match
the number of unknown transports. Good applications of this to the Middle
Atlantic Bight shelf are seen in the work of Bush (1981) who used mass,
temperature and salinity and Garfield (1978) who used mass, salinity and
¢s137. The calculated transports were for the northern shelf and near-
surface slope water into and the shelf water out of the shelf region.
The models were used to calculate annual average transports for the region
for a given year. The results agreed quite well with other independent
transport estimates.

This type of model provides a good technique for analyzing year-to-
year variations in transport, but it requires a good data base for ;

successful application. Bush (1981) has performed sensitivity analyses

83


NEMP area of interest. Following the last chapter is a bibliography
of all pertinent publications located by the authors, listed whether
they are cited in the text or not. Some of the listed entries are

accompanied by abstracts or annotations.

AVERAGE CONDITIONS

Coastal and offshore waters of the United States north of Cape
Hatteras (Fig. 2), can be subdivided on the basis of oceanographic
characteristics into four subareas: the Gulf of Maine, Georges Bank, the
Middle Atlantic Bight, and the Slope Water-Gulf Stream area. Most of the
general, descriptive oceanographic reports and atlases relevant to this
area deal with only one or two of these subareas, except for the summary
reports by Bumpus (1973) and Hopkins and Garfield (1977). Nevertheless
a general summary of average oceanographic and meteorological conditions
in the whole area can be obtained from these two reports and from those
prepared by Beardsley and Boicourt (1981), Williams and Godshall (1977),
Godshall, et al. (1980), and Bumpus (1976).

The average circulation off the northeastern U.S. involves seasonally
variable gyres in the Gulf of Maine and on Georges Bank, slow westward and
southward flow on the continental shelf in the Middle Atlantic Bight,
similarly slow southwestward flow in the slope water which occasionally
carries one or more Gulf Stream warm core rings (eddies), and relatively
rapid northeastward flow in the Gulf Stream (Fig. 3).

The gyre in the Gulf of Maine is a cyclonic (counter-clockwise) ro-
tating feature which is strongest in the spring and early summer months,
when flow into the Gulf from the Scotian Shelf and discharge from streams
in Maine, New Brunswick, and Nova Scotia are the greatest. During fall

and winter the gyre weakens, and its southern sector may break down allowing



ABSTRACT
Q

physical processes and features influencing the distribution and fate
of pollutants in the coastal and offshore waters of the northeastern United
States are identified and described. The general physical oceanographic
setting of this portion of the North Atlantic is briefly presented before
identifying the following relevant features and processes: estuarine effluent
plumes, upwelling, warm core rings and Gulf Stream meanders, fronts, density
stratification, the cold pool, bottom currents, and sediment transport. In
addition, field measurements of pollutant dispersion and quantitative models
and physical processes also are discussed.

Effluent plumes from the Chesapeake and Delaware bays, Hudson-Raritan
Estuary, Connecticut River and the Merrimack River are seen as significant
present or potential sources of pollutants or as features influencing dis-
tributional patterns of pollutants. Plume configurations are complex and
dynamic, varying significantly in time scales ranging from tidal to seasonal.

Upwelling has been detected and reported seasonally present along the
Virginia-New Jersey coastline, along the Rhode Island-Massachusetts coast-
line, near Nantucket Shoals and in Massachusetts Bay. In addition, some
persistent upwelling appears to be commonly found along the northern edae
of Georges Bank.

Warm core Gulf Stream rings and meanders have been frequently detected
to be interacting with the water mass over the continental shelf in the
Middle Atlantic Bight and invading Deep Water Dumpsite 106. Less frequently,
rings have been seen interacting with the water mass on Georges Bank.

Fronts separating water bodies with considerably different properties
have been studied along the northern edge of the Gulf Stream, separating

shelf water from slope water, surrounding the well mixed areas on Georges

iii


Meid, R. P. and G. L. Lindemann, 1979, The propa-
gation and evolution of cyclonic Gulf Stream
rings. J. Phys. Oceanogr. 9(6):1183-1206.

Numerical simulations of the propagation of
cyclonic Gulf Stream rings are made using a primitive
equation 2-plane model of a flat-bottomed two-layer
ocean with a rigid lid. Initially circular eddies
having upper and deep ocean maximum currents maxUy
and maxU, located at radial position 1 from the
center are allowed to evolve and four types of behavior
have been discerned: 1) dispersing rings possess
negligible nonlinearity and disperse rapidly; 2)
barotropic rings (U1 = Uz) are weakly dispersive,
Propagating recognizably for long periods of time,
and nearly barotropic eddies (Uy Up) slowly lose
coherence in the deep ocean; 3) upper ocean rings
propagate with a vortex present only in the upper
ocean; and 4) eastward-traveling eddies possess
circulations in the upper and lower oceans which
Propagate together stably to the east.

Changes in viscosity are found to be more
important to the longevity of the ring than are
changes in (maxUy)/s/2. Both westward ang north-
ward speeds increase with increasing maxU¢/maxU}
and increasing (maxU)/e/2. Speeds to the west are
found to be 2-3 km day-! and thgse to the north are
1-9 km day-! for 3 < (maxU;)/8/2 <15 and 0 «
maxU2/maxU; «1.2.

Meserve, J. M. 1974. U.S. Navy marine climatic
Atlas of the World. Vol. 7 - North Atlantic
Ocean. Naval Weather Service Detachment,
U.S. Naval Weather Service Command,
Washington, DC. 371 pp.

Miller, A. R. 1950. A study of mixing processes
over the edge of the continental shelf.
J. Mar. Sei. 9(2):145-160.

By means of T-S area diagrams, a method
of analysis is developed for the study of
closely spaced hydrographic data. In a transition-
al zone, such as that over the continental. shelf,
off southern New England, this method is useful
for following the continuity of the mixing
process. Changes in salinity at the edge of
the shelf are due, for the most part, to horizon-
tal advection. There are indications of non-
isentropic mixing on a smaller scale. From
the turbulent features of the region, as
indicated by instabilities, this condition is
not unexpected. .

Miller, A. R. 1952. A pattern of surface coastal
circulation inferred from surface salinity-
temperature data and drift bottle recoveries.
WHOI Ref. No. 52-28 (unpub. man.).

146

Miller, A. R. 1957. The effect of steady
winds on sea level at Atlantic City.
Monographs 2(10):24-31.

Met.

From a study of tidal records for Atlantic
City, New Jersey, and daily weather maps over
a period of six months, the elevation of the
sea surface associated with the geostrophic
wind field has been evaluated as a function of
the geostrophic wind velocity. The relationships
are expressed in a nomogram.

Assuming the angle of deviation between
surface and qeostrophic winds to be 20°, and
allowing for the static effects of atmospheric
Pressure, maximum elevation above the predicted
tide level is observed when the surface wind
blows 40° from the right of normal to the
coastline. In general, there appears to be a
12 hr lag between the winds and the associated
state of sea level.

Miller, Arthur R. 1958, The effects of winds on
water levels on the New England Coast.
Limnol, Oceanogr. 3(1):1-14.

Tidal records from Nantucket Sound, Cape
Cod; Montauk, Long Island; and Portland, Maine,
have been studied along with wind and barometric
observations from each location. Results of this
study show that departures from mean sea Tevel
due to wind may be resolved into two components.
The first is a component which refers to
symmetrical sinusoidal variation of sea level
departure as a function of wind direction and
applies to the outer coast and to the general
level of Nantucket Sound in particular.

The second is an asymmetrical component
which refers the responses of sea level at each
observing station to local wind force, direction,
fetch length, and local topography. Under dif-
ferent circumstances these components vary in
relative importance in determining the local
departure from mean sea level. In addition to
wind direction and velocity, duration and size
of wind field may determine whether one component
is more important than the other.

The varying importance of each component
probably governs the time-lag between peak winds
and maximum sea level departures which will vary
from several hours to as much as twenty hours.

Miller, 0. W., J. J. Geraghty and R. S. Collins.
1963. Water atlas of the United States.
Water Information Center, Inc., Port
Washington, N.Y., 40 plates.

Miller, M. C., J. C. Bacon, and I, M. Lissauer.
1975. A computer simulation technique for
0i1 spills off the New Jersey-Delaware
coastline. Report CG-D-137-75. U.S.
Coast Guard Res. & Dev. Center, Groton,
Connecticut.

Milliman, J. 0. 1973. Marine Geology in coastal and
offshore environmental inventory, Cape Hatteras
to Nantucket Shoals. Complement V. 10-1 to
10-91. Marine Pub. Series No. 3, University of
Rhode Island, Kingston, RI 02881.


45°

40°

35°

30°

25°

SHELF WATER FRONTAL POSITIONS
JUNE 1973— DECEMBER 1974

Figure 9.

| i i
80° 75° 70° 65°
Composite plot of locations of the shelf-slope front during June
1973-December 1974 compiled from weekly frontal analysis charts
derived from satellite infrared imagery. From "The Environment of
the United States Living Marine Resources - 1974". MARMAP Contribu-

tion No. 104. NOAA, National Marine Fisheries Service. Unpublished
report.

38



Schmitz, W. J. dr., J. F. Price, P. L. Richard-
son, W. B. Owens, D. C. Webb, R. E. Cheney,
and H. T. Rossby. 1981.
A preliminary exploration of the Gulf
Stream System with SOFAR floats. J. Phys.
Oc. 11(a):1194-1204.

SOFAR (sound fixing and ranging) floats
deployed for engineering tests during 1977-79
yield the first long-term quasi-Lagrangian
observations in the subsurface Gulf Stream
System. The character of these float tracks
supports the premise that the Gulf Stream is
a persistent, large-scale, vertically cohe-
rent jet at depths (approximately) within
and above the main thermocline, where mean
and eddy kinetic energies are roughly the
same and lateral motions of the Stream are
clearly delineated. A float track at thermo-
cline depth is visually coherent with the
track of a concurrently launched surface
drifter over the larger horizontal scales
traversed during the first few months of
their trajectories. Below thermocline depths,
fluctuation or eddy kinetic energies are
normally larger than the mean and a persis-
tent Guif Stream is difficult to detect.
However, deep motions that are visually
coherent with upper level flows may be
observed for an intermediate range of space
and time scales.

Eddy kinetic energies based on the float
data are compatible with existing Eulerian
estimates to the extent comparable. The
consistency of a quasi-Lagrangian eddy
kinetic energy estimate in the vicinity of
the thermocline, roughly 400 cm2 s~2, the
first such observation to our knowledge, is
indirect but relatively convincing. Zonal
and meridional variances for the float data
are also in line with existing Eulerian
results. Estimates of the frequency dis-
tribution of eddy kinetic energy for the
Jongest float trajectory available are
nearly identical to comparable Eulerian
results at frequencies less than about a
cycle per 20 days.

Schmitz, W. J., Jr., A. A. Robinson and F. C.
Fuglister. 1970. Bottom velocity
observations directly under the Gulf Stream.
Science 170:1192-1194.

Schopf, T. J. 1967. Bottom water temperature
on the continental shelf off New Enaland.

U.S. Geol. Surv. Prof. Paper 575-D, pp. 192-197.

Schroeder, E. H. 1963. North Atlantic tempera~
tures at a depth of 200 meters. Am.
Geograph. Soc. Serial Atlas of the Marine
Environment. Folio 2, 13 pp. 9 pl.

Schroeder, £. H. 1966, Average surface
temperatures of the Western North Atlantic.
Bull. Mar. Sci. 16(2):302-323.

157

Schubel, J. R., H. H. Carter and W. B. Cronin.
1976. Effects of Agnes on the distribution
of salinity along the main axis of the
bay and in contiguous shelf waters. In:

The effects of tropical storm Agnes on the
Chesapeake Bay estuarine system. Chesapeake
Research Consortiun, Inc. CRC Pub. No. 54.
The Johns Hopkins Univ. Press. pp. 35-65,

Schubel, J. R. and A. Okubo. 1972. Comments
on the dispersal of suspended sediment
across the continental shelves. Chap. 15
in: Shelf Sediment Transport: Process
and Pattern. D. J. ?. Swift, D. B. Duane
and 0. H. Pilkey (Eds.). Dowden, Hutchinson
and Ross, Inc., Stroudsburg, Pennsylvania.

Scott, J. T. and G. T, Csanady, 1976, Nearshore
currents off Long Island. J. Geophys. Res.
81:5401-5409.

Currents were observed for a 25-day period in
September 1975 at 11 km south of Long Island,
where the water is 32 m deep, at three levels by
using electromagnetic current meters. Tidal
currents were found to be moderately strong, of
the order of 20 cm s-l. Nontidal flow is caused
by wind stress, horizontal density contrasts due
to fresh water influx, and a lonashore surface
Tevel gradient sloping down southwestward. The
time-averaged flow has simple characteristics,
adequately described by classical Ekman models
in frictional equilibrium. By suitable changes
in the averaging period, quantitative estimates
of a bottom friction coefficient and a longshore
pressure gradient are deduced from the data. The
bottom friction coefficient agrees with what
one would estimate from boundary layer theory
for roughness elements of about 70-cm height.
The longshore pressure gradient deduced from the
behavior of currents agrees with the evidence of
geodetic leveling.


4° —

40°

39°—h

38° +

NEW JERSEY

NEW YORK j,gQM:
gignr 49
APEX:

75°

Figure 14.

T

73° 72°

Middle Atlantic Bight dumpsites for which dispersion studies have
been reported: 1. 12-Mile Sewage Sludge Site, 2, Non-toxic acid
site, 3. Non-toxic acid (35-Mile) Site, and 4. Toxic chemical
(106-Mile) Site. From Interstate Electronics Corp. (1978).

69


diffusion velocity of 0.25 cm+sec~! was close to the observed value for
the experiment series. Based on this work, Csanady (1981) concluded that
sluggish shear diffusion would last for many days provided that conditions
remained quiescent. However, meteorologic disturbances (storms and passing
fronts) and hydrographic features (warm core rings and other ocean fronts)
Probably interrupt quiescent periods often enough that they govern the
ultimate fate of barged industrial waste at the 106 Mile site.

An experimental dump of coal ash was conducted by Energy Resources
Corporation at the 106 Mile site (ERCO, 1981) for Consolidated Edison
Company of New York to allow the U.S. EPA permit application process to
continue. Analysis of a sample of coal ash from the dump showed a bulk
density of 0.94 g:cm-3, a particle density of 1.90 g-cm73 and a settling
rate of 12 m-min-1, The ash was enriched in heavy metals including Cr,
Cu, Mn, Ni, Va and Zn. Approximately 84% of the sample was in the sand
or silt size ranges. A strong seasonal pycnocline was present at the
106 Mile site at 20-35 m depth and exhibited increased turbidity prior to
the coal ash dump on September 15, 1981. After the dump commenced, acoustic
backscattering and water sample data showed that a portion of the dump
had penetrated the seasonal pycnocline to a depth of 100 m in 20 minutes,
while some ash still remained within it. This rapid settling rate
(5.0 mmin7!) is consistent with data that showed no evidence of material
within the pycnocline after 1 hour. After 1.5 hours, the acoustic system
showed no evidence of the plume. Calculations showed that 55% of the dis-
charged material (probably the sand and coarse silt-sized fractions)
settled well beyond the seasonal pycnocline within 0.25 hours of discharge.

It was estimated that 98% of the discharged material had rapidly settled

78


NOAA Technical Memorandum NMFS-F/NEC-17

Northeast Monitoring Program

Summary of the Physical Oceanographic
Processes and Features
Pertinent to Pollution Distribution
in the Coastal and Offshore Waters
of the Northeastern United States,
Virginia to Maine

U.S. DEPARTMENT OF COMMERCE
' National Oceanic and Atmospheric Administration
National Marine Fisheries Service
Northeast Fisheries Center
Woods Hole, Massachusetts

December 1982


°e5

°Os "On

*Lood plod ay} 40 2UazXa Leaue

26, (,
c ¢
LN NY

931 sodwo)

°2n

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Sp

a&

oh,

104


Garside, C. and T. C. Malone. 1978. Monthly
oxygen and carbon budgets of the New York
Bight apex. Est. & Coast. Mar. Sci, 6:93-104.

* This paper is a compilation of source material
and data gathered during 12, 3 day cruises aboard
the R/V COMMONWEALTH at monthly intervals,
September 1974-August 1979. The distribution of
primary production salinity, temperature, dis-
solved oxygen and particulate organic carbon are
used to establish monthly oxygen balance for

the apex of the New York Bight. "The monthly
regression lines of surface oxygen flux against
particulate organic carbon, the monthly mean
surface flux calculated from the spatially
unweighted mean POC, the number of points used
and the correlation coefficient of the rearession
line and the annual mean values of al] paraneters
are tabulated."

Garvine, R. W. 1975. The distribution of
salinity and temperature in the Connecticut
River Estuary. J. Geophys. Res. 80(9):
1176-1183.

Garvine, R. W. 19793. An integral hydrodynamic
model of upper ocean frontal dynamics: Part I.
Developnent and analysis. J. Phys. Oceanogr.
9(1) 21-18.

The paper develops and analyzes a model of
frontal-scale dynamics applicable to established,
persistent upper ocean density fronts, The effects
of interfacial friction and mass entrainment arising
from turbulent dissipative processes are incorpora-
ted as well as the effects of earth rotation and
wind stress. The model is of hydrodynamic character
in that the circulation is not permitted to do its
own mixing. The equations of motion are solved
after their integration over the vertical from the
pycnocline bottom to the sea surface. Two indepen-
dent frontal length scales are found: one is Lt,
the dissipative length scale, defined as the ratio
of the asymptotic pycnocline depth to the magnitude
of the interfacial entrainment coefficient; the
other is the baroclinic Rossby radius, the internal
wave phase speed divided by the Coriolis parameter.
The ratio of these length scales forms the funda~
mental parameter of the model dynamics, Pp, called
the rotation parameter. For large values of Pr
the frontal length scale is the Rossby radius alone
and the model dynamics show features in common with
the inertial, inviscid Gulf Stream theories. For
smal] values of Py the frontal zone can have a
double structure with the inner region corresponding
to the nonrotational dynamics explored in a previous
Paper. For values of order one both dissipative and
rotational effects enter the dynamics.

127

Garvine, R. W. 1979b, An integral hydrodynamic
model of upper ocean frontal dynamics:
Part II. Physical characteristics and
comparison with observations. J. Phys.
Oceanogr. 9(1):19-36.

The physical characteristics of a model of an
upper ocean front are examined and compared to
observations. The model was developed and analyzed
in a companion paper. 1t applies to the mean
circulation and hydrooraphy of established
persistent fronts. The results for a case where
turbulent transport and earth rotational effects
are both important are examined in detail. The
circulation then contains a jet for the velocity
parallel to the front including cyclonic shear
but with speeds that are below geostrophic values.
The circulation normal to the front shows
strong two-sided convergence and sinking near
the surface front. The question of upward
versus downward mass entrainment is examined in
terms of its impact on the model circulation.
Five frontal cases are examined and compared
to field observations. These cover a wide range
of frontal scales from a river plume front to
the Gulf Stream front. The river plume front
nearly corresponds to a limiting case for the
mode] where rotation is negligible and turbulent
dissipative effects dominant, while the Gulf
Stream front corresponds nearly to the ovposite
limiting model case where dissipation is
negligible and rotation dominant. The other
cases fall between these two limits.

Garvine, R. W. 1980. The circulation dynamics and
thermodynamics of upper ocean density fronts.
J. Phys. Oceanogr. 10:2058-2081.

This paper extends a previous hydrodynamic cir-
culation model of established, persistent upper
ocean density fronts by including a thermodynamic
or buoyancy equation in the integral treatment. An
analysis is also conducted of the variables related
to the kinetic and potential energy budgets in the
frontal zone. A comparison of the new results with
previous ones shows satisfactory agreement. The
new mode? is used to explore three frontal types of
widely different scale or rotation effect, a river
plume front, a Sargasso Sea front and the Gulf
Stream front. As the scale increases, the influence
of rotation increases and the effect of interfacial
turbulent transport diminishes. Also, with increas-
ing scale the strength of the downstream (along-
front) flow increases while the cross-stream flow
diminishes, but always shows a two-sided convergence
near the surface front. The kinetic energy dis-
sipation decreases rapidly with dissipation times
of resident kinetic energy increasing from ten
minutes for the river plume front to a week for the
Gulf Stream front. The model results are examined
in an attempt to answer three questions about the
circulation dynamics. They indicate that the direc-
tion of turbulent mass entrainment is always down-
ward, that fronts always spread, even if slowly,
relative to the ambient fluid, and that the cross-
stream flow near the surface front always shows a
two-sided convergence.


Robinson, A. R., J. R. Luyten and F. C. Fuglister

1974.
Transient Gulf Stream meandering. Part I:
An observational experiment. J. Phys.
Oceanogr. 4(3):237-285.

The results from an observational experi-
ment on the mesoscale space-time variability
of the Gulf Stream are reported. Various
techniques, including aerial surveys, ship
trackings of the 15C isotherm at 200'm,
drogues and moored current meters were used
and are compared, to give estimates of the
variability of the motion over a wide range
scales. A two-week time series of daily
tracks of the Stream near 70W are used to
interpolate instantaneous paths over 2° of
longitude. These paths provide the first
detailed information on the small-scale
variability of the path indicator of the
Gulf Steeam northeast of Cape Hatteras.
Similarly, the long time series of triveekly
aerial surveys provides a detailed picture
of the evolution of a large-scale meander,

Ruzecki, Evon P, 1981.
Temporal and spatial variations of the
Chesapeake Bay Plume, P. 111-130. In:
Chesapeake Bay Plume Study - Superflux
1980. NASA Conference Publication 2188.
eds. J. W. Campbell and J. P. Thomas,
5l6pp. Scientific and Technical Infor-
mation Branch, National Aeronautics and
Space Administration, Washington, D.C.

Historical records and data obtained
during the Superflux experiments are used to
describe the temporal and spatial variations
of the effluent waters of Chesapeake Bay.
The alongshore extent of the plumé resulting
from variations of freshwater discharge into
the Bay and the effects of wind are illus-
trated. Variations of the cross-sectional
configuration of the plume over portions of
a tidal cycle and results of a rapid-underway
water sampling system are discussed.

Ruzecki, E. P., C. Walsh, J. Usry and J.
Wallace. 1976.
The use of the EOLE Satellite System to
observe continental shelf circulation.
Eighth annual offshore Tech. Conf.,
Houston, Texas. P.697-708.

Ryther, J. H. & Dunstan, W. M. 1971.
Nitrogen, phosphorus and euthrophication
in the coastal environment. Science 171:
1008-1013.

Surface samples were collected from eight
stations in Great South Bay, Moriches Bay, and
the Forge River in one set of experiments and
from coastal and open ocean regions off New
York and New Jersey as part of an ocean cruise
in September 1969.

Enrichment studies were done on water
samples taken from both locales using nitrogen
and phosphorus as variables. Results show
that nitrogen was the primary limiting fac-
tor to algal growth.

High content of particulate organic mat-
ter characteristic of the New York Bight ex-
tended seaward for less than 80 km to the
east and southeast, wheras pollution occurred
at least 240 km to the south, along the New
Jersey coast to Delaware Bay.

155

Saltzman, 8. and C. M. Tang. 1975. Formation
of meanders, fronts and cutoff thermal
pools in a baroclinic ocean current. J.
Phys. Oc. 5:86-92.

Using an analytical model similar to that
previously applied by the authors to the atmosphere,
calculations are made showing how second order,
nongeostrophic effects can modify a two-layer
baroclinic wave system that grows exponentially
from a small perturbation in a uniform zonal
ocean current. It is shown that many of the
asymmetric features characteristic of meander-
ing ocean currents develop, including "fronts
and cutoff cyclonic cold pools to the south and
anticyclonic warm pools to the north of the
axis of the mean current. The implication is
that all of these features can be viewed as
being the simultaneous consequence of baroclinic
instability (with attendant second order finite
amplitude effects) of a broader, more uniform
current that might tend to be forced externally
by the wind stress and thermohaline processes.

Sarabun, C. C., Jr. 1981. Mapping watermass
boundaries using fluorosensing lidar. In:
Chesapeake Bay Plume Study: Superflux 1980.
Campbell, J. W. and J. P. Thomas (Eds. }
NASA Conf. Publ. 2189, NOAA/NEMP III 81
ABCDFGO042. NTIS, Springfield, VA, 522 pp.

Sarmiento, J. L. and K. Bryan. 1982. An ocean transport
model for the North Atlantic. J. Geophys. Res.
87(C1): 394-408.

Three-dimensional solutions are obtained for the
circulation of the North Atlantic using a robust
diagnostic model. In contrast to previous diagnostic
models the robust diagnostic model incorporates the
conservation of the large-scale fields of heat and
salinity as well as momentum, An approximate fit to
observed fields of temperature and salinity is obtained
by a closure condition. The method is robust in the
sense that it does not have the extreme sensitivity
to the density input fields of the classical diagnostic
method. Equilibrium solutions are obtained by
numerical integration of the time-dependent equations.
Error estimates for the velocity field can be obtained
indirectly from the numerica? solutions. Temperature
observations used as input have an effective resolu-
tion of 3° x 3° of latitude and longitude and a
sampling error of + 0.15°C. The equivalent vertically
integrated velocity error is estimated to be + 0.5-1.0
cm/s depending on bottom topography. The suitability
of the model for geochemical wark is judged by com-
parison with heat and salinity balance estimates.

Best results are obtained for the case in which the
model has a minimum observational constraint below
the surface.

Saunders, P. M. 1971. Anticyclonic eddies formed
from shoreward meanders of the Gulf Stream.
Deep Sea Res. 18:1207-1219.

* Author uses XBT data in the area 39-40N,
68-71W_and moored current meter data from 13m,
53m, 185 m, 207 m, 1044 m, 2066 m, at 39-12 N,
70-03 W. A Gulf Stream anticyclonic eddy formed
during the period 15 September - 4 December 1969
and remained at the edge of the shelf. Energy
computation indicated the eddy circulation is
confined to the upper 1000 m and energy is pri-
marily potential energy.


Although the research described in this report has been funded in part by the U.S.
Environmental Protection Agency, it has not been subjected to the Agency's required
Peer and policy review and therefore does not necessarily reflect the views of the
Agency and no official endorsement should be inferred.



°ep

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105


during the fall and winter. Additional studies by Collins (unpub. manu-
script) * showed maximum returns of seabed drifters in December 1975, January
and February 1976 from releases in Rhode Island Sound during May and
September 1975. In both studies the development of upwelling conditions

was associated with the westerly-northwesterly winds of late fall and winter.
Collins also found support for offshore drift of surface waters during this

period in his analysis of sea level records.

WARM CORE RINGS AND GULF STREAM MEANDERS

Meanders and warm core rings formed in the Gulf Stream are mesoscale
(100 km or more) features which exhibit relatively slow translational
speeds (kilometers per day) and rapid angular speeds (kilometers per hour).
Both types of motion can affect the transport or dispersion of suspended
or dissolved pollutants dumped into the meanders and rings or in the water
they entrain from the shelf and slope water masses. The current shear
found near the high speed (>1 m-sec-!) portion of these features can be an
effective dispersive mechanism, while also transporting the pollutant
materials considerable distances along circuitous trajectories.

Warm core rings and Gulf Stream meanders are apparently the principal
source of physical variability in the slope water region off the Northeast
coast. Monitoring this variability has only been possible since the latter
part of 1973, when high resolution infrared data became available rountinely
from NOAA environmental satellites.

North of Cape Hatteras the Gulf Stream turns northeast into deep water
and tends to meander with increasing amplitude downstream. The meanders,

with wave lengths of about 320 km, have been found to propagate downstream

3

Co., P. 0. Box 2038, Pittsburgh, PA 15230. "Upwelling in eastern Rhode
Island Sound: A seabed drifter study."

26

Collins, Barclay, Geology & Interpretation Dept., Gulf Science and Technology


Hydrodynamic Modeling of Entire Shelf

The recent work of Beardsley and Haidvogel (1981) is an example of
a systematic approach to hydrodynamic modeling of the entire Middle Atlantic
shelf. Their published work is just the first part of what seems to be a
very promising study. Their model is two-dimensional, and only qualitative
comparisons with data have been made, but they admit that much more detail
has to be added and more experimenting with the model has to be performed
before detailed comparisons with data can be made.

This is the type of model that can be used as input to a finer grid
model of a subregion or to a diagnostic model. Once more work has been
done on this full-shelf model, it could be quite useful as a predictive

tool.

Oi] Spill-Fisheries Impact Modeling

An example of how hydrodynamic transports can be coupled with eco-
logical-type models is seen in the work of Reed, Spaulding and Cornillon
(1980). They were interested in predicting the effects of oi] spills on
the fishery on Georges Bank. The total model is composed of three components:
transport, fishery and 071 spill fate. The transport as discussed in their
report was determined from the observed seasonal patterns, simple wind-
driven dynamics and random walk dispersion. More recent work incorporates
3-D hydrodynamic calculations. Much detailed effort has gone into the
fishery and oil-spill components. Various aspects of these components
have foundations in experiments and observation. This is another good
example of how models can be used for prediction, assuming various

scenarios.

85


Although these four groups have different physical characteristics,
their combined dumping in one area may cause some unforeseen effects. For
example, rapid transport of coal ash to bottom if contaminated through
sorptive processes by other chemical wastes prior to descent may provide
a mechanism by which wastes from groups 1 and 2 (above) may impact the

ocean bottom.

MODELS

It. is quite appropriate to recall some of the ideas presented by
B. H. Ketchum in his wrap-up comments to the Symposium on the Middle
Atlantic Continental Shelf and the New York Bight (Ketchum, 1976) as
they pertain to modeling. In particular, the following:

"What else do we need to know? We need a useful, predictive
model.... Modelers sometimes assume that if they can draw enough
boxes and enough arrows on a piece of paper, they suddenly know
something about the system. Actually, it works the other way around.
The boxes and arrows are nonsense until something is known about the
system and then you can start to build a model based on what you
know. If one builds an entirely conceptual model (obviously nobody
does; whatever information is available is used), one can delude
oneself and others that something is known about the system.

"What can a model do? It can help define the gaps of knowledge
where we need more precise information. If it fails in doing this,

then it fails in the first purpose of a model. Even more importantly,

80



in late summer and by late October-mid November thermal stratification
is completely destroyed. From then until spring the water mass is
vertically isothermal with the coldest water found nearshore and a weak
horizontal gradient toward warmer water offshore.

An abrupt gradient to warmer, saltier water, called the Shelf/Slope
Front, is usually located in the vicinity of the edge of the continental
shelf. Long-term average motion of the shelf water mass is approximately
parallel to the bathymetry toward the southwest, with speeds of about
5-10 cm-sec"! at the surface and 2 cm-sec-! or less in the bottom water
(Hansen, 1977; Han and Niedrauer, 1981; EPA, 1978). Short period events,
such as storms, can cause much more energetic variations in the flow field,
and tidal currents on the inner shelf can range up to 100 cm-sec”! near
entrances of estuaries and generally up to 20 cm-sec-! elsewhere.

The shelf water can be divided into two modes, low salinity (below
33.2 °/oo and high salinity (above 33.4 °/oo), as revealed by the volumetric
analyses of Hayes (1975) and Wright and Parker (1976). The less saline
mode is generally found along the inner shelf in depths less than 60 m,
and the more saline is found farther offshore in depths oreater than 60 m.
Nearly half the annual runoff into the Middle Atlantic Bight usually occurs
during the spring (Bigelow and Sears, 1935), lowering nearshore surface
salinities to less than 32 °/oo. During the year 157 km3 of runoff in the
Middle Atlantic Bight mixes with slope water to produce about 2,400-

3,400 km3 of shelf water (Wright, 1976a; Bush, 1981). Shelf water losses
from the Middle Atlantic Bight occur near Cape Hatteras where the Gulf
Stream entrains it (Fisher, 1972) and across the Shelf/Slope Front in

turbulent exchange processes.



in late April to early May) and lasts throughout the summer into early
fall, until the normal seasonal overturn (from October to December, but
mostly in November) mixes away the vertical density structure and the
water column becomes vertically isothermal.

The cold pool normally covers an area on the bottom between the 40
and 100 meter isobaths (20-60 fathoms) an area of approximately 88,000 km@
between Georges Bank and Cape Hatteras. The average thickness of the
feature is about 35 meters and extends from the bottom to the base of the
seasonal thermocline (within 20-30 meters of the surface). This represents
a volume of 3,100 km3, or about 30% of the total volume of shelf water
jin the Middle Atlantic Bight.

The cold pool is a relatively slowly changing feature (by virtue of its
bathymetric location) when compared to the more active zones of lateral
mixing seaward and vertical mixing shoreward, with a long-term average
flow of about 1-3 cm-sec! southwestward (Mayer et al., 1979). However,
the cold pool is in a state of constant change, and it can be acted on by
several processes either singly or simultaneously, some of which are as
follows:

Wind events can cause upwelling nearshore, moving the shoreward
leading edge of the cold pool toward the beach and sometimes even into
the surf zone (Hicks and Miller, 1980). Other wind events, if persistent
enough, also can influence the offshore edge of the cold pool, forcing
it and the shelf water-slope water front to move seaward (Csanady, 1978).

Gulf Stream rings migrating along the shelf edge to the southwest
through the Middle Atlantic Bight can cause perturbations in the subsur-
face shelf-slope front and the seaward edge of the cold pool by advecting

upper slope water (>12°C) shoreward over the edge of the continental

50


WARM CORE RINGS AND GULF STREAM MEANDERS

Reference

Ikeda (1981b)

McWilliams & Flier]
(1979)

Meid & Lendemann
(1979)

Hart (1975a, b)
Luyten & Ribinson
(1974)

Flier? (1979)

Csanady (1979)
Newton (1978)
Semtner & Mintz
(1977)

Schmitz & Vastano
(1975)

Bretherton & Karweit
(1975)

Ikeda (1981a)

Firing &-Beardsley
(1976)

Saltzman & Tang
(1975)

Area
Gulf Stream Rings
Gulf Stream Rings
Gulf Stream Rings
Gulf Stream Rings
Gulf Stream Meandering
Gulf Stream Rings
Gulf Stream Rings
Gulf Stream Meander
Gulf Stream Rings and
Meanders
Gulf Stream Rings
Gulf Stream Ring

Gulf Stream Meanders
and Eddies

cyclonic vortex

Gulf Stream Meanders

92

Description

asymmetric instability of
rings and evolution of shape
in nonlinear case

idealized study of vortex
behavior

numerical simulation of ring
propagation in ideal ocean

instability of ring on
sloping bottom

analyzed dynamics in terms
of measurable quantities

how are size & strength of
ring related? shape of
isotherms

birth and death of rings

compares with dynamics of
atmospheric jet stream

numerical simulation of
western North Atlantic

investigate entrainment and
diffusion in ring using
temperature data

6 layer, quasi-geostrophic
model; try to simulate ring

2-layer, quasi-geostrophic
model to study meander growth
and eddy detachment

numerical simulation on
B plane

analytic model to show that
asymmetric features of
meandering ocean currents
can develop


1979.
of some shallow wind-driven currents. J.
Phys. Oceanog. 8:218-220.

Winant, C. and R. Beardstey. A comparison

Worthington, L. V. 1964. Anomalous conditions
in the slope water area in 1959. J. Fish.
Res. Bd. Canada 21:327-333.

Wright, W. R, 1976. The limits of shelf water
south of Cape Cod, 1947 to 1972. J. Mar.
Res. 34(1):1-14.

Some 19,000 bathythermograms and 1,600 oceano-
graphic stations in the region 39° to 41°N, 69° to
72°H have been examined for evidence of changes in
the character and position of the shelf water/slope
water boundary. Results show a) the boundary,
identified by the 10° isotherm, intersects the bottom
within 16 km of the 100-m curve about 80 percent of
the time, with a seasonal progression from the south
in the winter to north in the fall; b) at the sea
surface the boundary position is much more variable,
averaging 52 km seaward of the 100-m curve in winter
and 72 km seaward in late summer; c) detached parcels
of shelf water are found in the slope water at all
times of the year, with maximum occurrence in late
spring and early summer; and d) the combination of
entrainment at Hatteras and production of detached
parcels appears to account for the shelf water/slope
water exchange required by salt balance considerations.

Wright, W. R. 1976a. Physical oceanography -
The western slope water. In: Suimary of
Environmental Information on the Continental
Slope Canadian/U.S. Border through Cape
Hatteras. Manuscript submitted to U.S. Bur.
Land Management, Marine Minerals Div.

NTIS Publ. 2840000/AS.

Wright, W. R. and C. £. Parker, 1976. A
volumetric temperature/salinity census
for the Middle Atlantic Bight. Limno?.
Oceanogr. 21(4):563-571.

Yentsch, C. S. 1977. Plankton production. MESA N.Y.
Bight Atlas Mongr. No. 12, N.Y. Sea Grant Institute.
Albany, NY. 25pp.

* Physical and biochemical factors controlling pri-
mary production in Bight waters are described. High
temperatures attribute to increased vertical mixing
during winter and strongly stratified waters during
summer. Low productivity during summer is caused by
limited nitrogen supplies in the euphotic zone. Pro-
ductivity of the slope waters is limited by vertical
mixing. The spring bloom stems from decreased verti-
cal mixing induced by solar radiation and relaxation
of winds. Autumn productivity is increased resulting
from a breakdown in the summer thermocline induced
by colder temperatures and increased winds.

Young, R. A. 1978. Suspended matter distribution in”
the New York Bight apex related to Hurricane Belle.
Geology 6:301-304.

166

Young, R. A,, T. L, Clarke, R. Mann, and D. J. P. Swift.
1981 Temporal variability of suspended particulate ‘
concentrations in the New York Bight. J. Sed. Petrology!
51(1): 0293-0306. :

Temporal variability observed ‘in-several time series
of suspended matter measurements, obtained by light
scattering and conventional water sampling, has been
examined to identify significant time scales with respect
to synoptic characterization of regional suspended mat-
ter distributions in the inner New York Bight. Processes.
with periods corresponding to surface waves (seconds) and
storms (days) apparently make the strongest contributions
to overall concentration variability, and tidal motions
appear to have only a weak influence on near-bottom sus-
pended load. An empirical model is proposed which
assumes that concentration variance is linearly related
to the mean concentration, both increasing in response
to such processes as wind-wave mixing and boundary layer
interactions with the bottom. Data obtained during the
study support the model. This model is used in a num-
erica] experinent which suggests that fafr-weather
variability in processes affecting near-bottom concen-
trations is probably not sufficient to cause serious
errors in suspended matter studies in the New York Bight.

Zimmerman, Herman 8. 1971, Bottom currents on the New
England continental rise. Jour. Geophys. Res.
7el24) 5865-5676.

Current meters were placed approximately 2 meters
off the bottom at depths from 2900 to 5000 meters on the
continental rise near the New England seamount chain.
Current velocities greater than 15 cm/sec were recorded
‘in a west-southwest direction, parallel to the regional
contours. The greatest velocity recorded was 26.5 cm/sec
toward the southwest. Spectrum analyses of the time-
series curves have resolved periodic motions superimposed
on secular, contour-following trends. An interaction
between the contour current and the Gulf Stream is also
apparent. These data suggest that the contour current,

a Western Boundary Undercurrent, is competent to
transport and erode continental rise sediments. A
significant sediment dispersal system parallel to the
regional slope is confirmed to be operative on the
present-day continental rise,


discharges. Larger particles did settle with higher velocities

(0.5-1.0 om-sec-1), but the sludge plume had much lower settling velocities
(10-3 cm-secTM!), The sludge plumes were also noted to be very sensitive to
the development and persistence of thermally-induced shallow pycnoclines.

In the absence of pycnoclines, during periods of strong winds, mixing was
shown to cause rapid (5.5 hr.) dispersal of the sludge to background levels.
Effective vertical diffusivities were measured to be approximately
103cm2-sec7!. Subsurface dilutions varied from 200:1 at a few meters

depth to 600:1 at the surface.

Proni and Hansen (1981) and Duedall et al. (1981) reported from
acoustic backscattering data that reflecting layers of sewage sludge ap-
peared in the 5-10 m pycnocline after a stationary dump of the material at
the 12 mile site in July 1976. These layers moved horizontally relatively
rapidly (50 cm:secTM!) away from the dump location. Their speed decreased
with increasing distance from the dump. Such layering may be responsible
for the widely varying concentrations observed immediately after a dump.
Material shallower or deeper than the seasonal pycnocline dispersed with
a rate more in agreement with traditional estimates.

These field measurements of sewage sludge dispersion, although few,
clearly demonstrate the dispersive nature of the water column on the
12 mile sewage sludge dumpsite. Dispersion is most rapid when the meteoro-
logic and hydrographic conditions include high winds and an unstratified
water column. High background Tevels from New York Harbor contribute to
the apparent "rapid dispersion" by masking the detection of dumped sludge

for longer periods of time.

71


c. Most rings in the Middle Atlantic maintain close contact with
the continental slope, especially in the Hudson Canyon area
and southward.

d. Entrainment of Gulf Stream water into the vicinity of the
continental slope is characteristic of rings that occur south
of Georges.

e. Longevity of rings is more variable in the vicinity of Georges
than in the Middle Atlantic.

f. High amplitude meanders are common S and SE of Georges Bank
but extremely rare in the Middle Atlantic.

g. Low amplitude meandering of the Stream just north of Cape
Hatteras sometimes brings it close to the continental slope
as far north as the offing of Chesapeake Bay causing entrain-
ment of shelf water and the Stream may directly force warm

saline water onto the shelf.

Interactions with the 106 Mile Dumpsite

Bisagni (1976) determined from two years' data (1974-75) that only
about three warm core rings each year moved far enough to the west to
affect the 106 Mile Dumpsite. Figure 8 shows a vertical temperature
section through a ring which was centered just northeast of and covering
the dumpsite in July 1975. The seasonal thermocline extended to 50 m
depth across the ring, while the main thermocline began at a depth of
about 500 m; much deeper than in the surrounding slope water. Between
50 m and 500 m depth in the ring's core occurred a thick layer of nearly
isothermal water approximately 100 km across. Clearly the presence of

a warm core ring and its currents could have profound effects on the water

column and dispersion of waste dumped at the 106 mile site.

32



Georges Bank
The waters around the edges of Georges Bank (depths >60 m) exhibit
a seasonal cycle similar to that observed in the surface layers of the
Gulf of Maine. Conditions are vertically uniform in winter. Thermal
stratification with a strong thermocline develops in the spring and sumer.
Winter cooling reestablishes a well-mixed, vertically uniform water column.
Over the shallow portions of Georges Bank, where water depth is less
than about 60 m, the strong tidal currents keep the water column well-
mixed throughout the year. While the water temperature exhibits seasonal

warming and cooling, no vertical stratification develops.

Middle Atlantic Bight
The water volume in the Middle Atlantic Bight is divided into a narrow,
coastal, low salinity band affected primarily by outflow from three major
estuaries, a shelf region ranging between 20 m and 100 m depth, and the
outer shelf region at the shelf break which receives intrusions of more
saline and warmer slope water and is characterized by the shelf-slope front.
The shelf region is occupied by low salinity water ranging between
30 °/oo near shore to 35 °/oo at the bottom along the shelf break. The
average salinity over the shelf is around 32.5 °/oo at the surface to
35 °/oo along the bottom. Water temperature varies seasonally, ranging
from 2°C in the nearshore zone during February-March to values as high as
30°C, but generally 25-26°C in late summer. In winter the water is
vertically homogeneous with temperature increasing seaward at all depths.

The water begins to warm by late April with a thermocline established by

44


Bowman, M. J. and D. A. Jay. 1975. The physical
oceanography and water quality of New York harbor
and western Long Island Sound. Mar. Sci. Res.
Center Tech. Rep. No. 23, Refn, 75-7, NY Sea Grant
Inst., Marine Sci. Res. Center, State Univ. of
New York, Stony Brook, NY 11794.

* Interpretations of hydrography and circulation of
New York Harbor and western Long Island Sound and data
available from the results of studies conducted by the
Marine Sciences Research Center are given in this tech-
nical report. Emphasis is placed on the transport of
salt and water between the harbor and Long Island Sound
through the East River tidal strait for an increased
understanding of pollutant transport. "Although the
available data are insufficient to produce a complete
description of mixing and transport processes in the
Sound and the Harbor, they are sufficient to provide
preliminary answers and to guide further research."

Bowman, M. J. and P. K. Weyl. 1972. Hydrographic
study of the shelf and slope waters of New
York Sight. State Univ. of New York,

Mar. Sci. Res. Center Tech. Rep. #1.

This report presents results obtained from
three oceanographic cruises made by the Marine
Sciences Research Center during 1970 and 1971 to
investigate the physical characteristics of the
shelf and slope waters of New York Bight.

The existence of a sharp temperature-salinity
front over the continental slope was confirmed
during the months of June 1970 and April 1971.
Associated with this front is a subsurface warm
tongue delineated by a temperature maximum which
intersects the edge of the shelf at a depth of
about 150 meters.

Data obtained in August 1971 showed no
evidence of any temperature front over the slope
but suggested the existence of an irregular
salinity gradient in this region.

Three factors appear to be important in the
dynamics of the formation and dispersion of the
subsurface warm tongue aver the continental slope.
These are the existence of the temperature-
salinity front and the associated convergence
Zone, the meanderings of the Gulf Stream and the
creation of warm eddies, and the intrusion of
Labrador water into the Bight.

Bownan, M. J. and Wunderlich, L. 0. 1977.
Hydrographic properties. MESA NY Bight
Atlas Monograph No. 1, 78 p., NY Sea
Grant Institute, Albany, NY

* This monograph presents an extensive summary of
original and archived data on the hydrographic
properties of the New York Bight. Cycles of
temperature, salinity and density characteristics
are determined from seasonal patterns of insola-
tion, river runoff, evaporation minus precipita-
tion, winds, ocean currents and shelf/slope
exchanges. Principal hydrographic features of
the outer continental shelf are strong tempera-
ture/salinity fronts between shelf-water and
slope-water. Shelf/slope water exchanges are
dominated by small scale dynamics of which little
is known and quantified.

Bretherton, F. and M. Karsweit. 1975. Mid-ocean
mesoscale modeling. Proceedings of Symposium
on Numerical Models of Ocean Circulation.
National Acad. Sci., Wash., OC, p. 237-249.

113

Brown, D. W., R. E. Callaway and A. M. Teeter.
1976. Preliminary analysis of the dispersion
of sewage sludge discharged from vessels to
the New York Bight waters. Am, Soc. Limnol.
Oceanogr, Spec, Symp. 2:199-211.

* This data report focuses on ocean disposal
and the dispersion of sewage treatment plant
wastes discharged into the New York Bight apex.
Field experiments monitored sludge vessels during
1974-1975 aboard the R/V Atlantic Twin. An
inter-ocean STD/beam transmissometer was used

to monitor in situ concentrations of Total
Suspended Matter (TSM). Objective analysis of
each field experiment is made and alternate
solutions are discussed.

Brown, M. F. and 0. R. Kester, 1981. Fate of
ocean-dumped acid-iron waste in a MERL
stratified microcosm (abstract). Program
and Abstracts, Third International Ocean
Disposal Symposium, Woods Hole Oceanographic
Institution, Woods Hole, MA, Oct. 12-16, 1981.

Brown, W. S. and R. C, Beardsley. 1978. Winter
circulation in the western Guif of Maine:
Part 1. Cooling and water mass formation.
J. Phys. Oceanogr. 8:265-277.

Buller, R. J. and J. R. Webster. 1950. Drift
bottle releases off New Jersey. Spec.
Scientific Rep: Fisheries No. 10.

Bumpus, D. F. 1957. Surface water temperatures
along the Atlantic and Gulf coasts of the
United States. Spec. Scientific Rep:
Fisheries No. 214. .

Bumpus, D. F. 1961. Drift bottle records for
the Gulf of Maine, Georges Bank, and the
Bay of Fundy, 1956-58. Spec. Scientific
Rep: Fisheries No, 378.

Bumpus, D. F. 1964. Residual drift along the
bottom on the continental shelf in the
Middle Atlantic Bight area. Limnol.
Oceanogr. 10 (Suppl.):R-50-R53.

Bumpus, D. F. 1969. Reversals in the surface drift
in the Middle Atlantic Bight area. Deep Sea
Res. 16 (Supp].):17-23.

Reversals in the surface drift off the Middle
Atlantic States in mid-summer have been observed
more frequentiy during the 1960s than previously.
These are associated with the low runoffs of the
Delaware and Hudson River watersheds during this
period especially during the drought of 1963-1966.
It is predicted that surface current reversals may
be expected at any time, April-September, when the
wind is from the southern sector and the runoff
during March, April and/or May has been much below
normal.


constant except for warping of temperature strata caused by aperiodic
incursions of the north wall of the Gulf Stream or warm core Gulf Stream
rings.

The third layer, deep slope water, exists from about 600 m to bottom
and is a zone of very slow temperature decrease to a minimum of 2.2°C
at about 4000 m. Variations in the lower portions of this layer over the
continental rise may be due to the position of the Western Boundary Under-

current, a deep geostrophic, near-bottom current.

COLD POOL

The cold pool, so named by Bigelow in 1933, is a continuous sub-
surface water type located on the continental shelf bottom between Georges
Bank on the northeast to Cape Hatteras at the southwest. This feature
was referred to as remnant "winter water" by Bigelow (1933), Ketchum and
Corwin (1964), and Whitcomb (1970) who believed it to be formed from the
winter cooling of mixed Middle Atlantic Bight shelf water. With hydro-
graphic data portrayed by Colton, et al. (1968) and Limeburner et al. (1978),
the feature can be traced to the north along the eastern edge of Georges
Bank and into the Gulf of Maine, where temperature and salinity relationships
suggest a possible source of replenishment (Beardsley et al., 1976 and Hopkins
and Garfield, 1979). To the south the cold pool feature has been traced
past the offing of Chesapeake Bay to Cape Hatteras where three major water
masses (shelf, slope, and Gulf Stream) meet.

The cold pool becomes an identifiable feature each year beginning with

spring surface warming and the onset of thermal stratification (generally

49


Holland, W. R. and L. 8. Lin. 1975a. On the
generation of mesoscale eddies and their
contribution to the oceanic general cir-
culation. I, A preliminary numerical
experiment. J. Phys. Oceanogr. 5:642-657.

Numerical experiments on the wind-driven ocean
circulation in a closed basin show that mesoscale
eddies can appear spontaneously during the inte-
gration of the equations of motion for a baroclinic
ocean, For some values of the basic parameters
governing the flow, the solutions reach a steady
state while for other values finite-amp1i tude
eddies remain a part of the final statistically
steady state. In the eddying cases the solutions
can be regarded as a mean flow upon which is
superimposed @ set of eddies which propagate
westward at a few kilometers per day. The
eddies typically have horizontal wavelengths of
a few hundred kilometers.

Analyses of the energetics show the eddies
to be generated by the process of baroclinic
instability. The potential energy of the mean
flow is released to supply energy to the eddies.
The computed Reynolds stresses, while small
compared to the terms in the geostrophic balance
of the mean momentum equations, do have a strong
influence on the mean circulation and, in fact,
the deep mean circulation is driven entirely
by the eddies. If the flow were steady, there
would be no fiow in the deep layer in this mode?.
Finally, the computed curl of the Reynolds stresses
shows that the vorticity balance of the mean
flow is strongly affected by the presence of
mesoscale eddies.

In the first part of this report we describe
the two-layer model and discuss its numerical
formulation. Then the results of a preliminary
eddy experiment are discussed in detail,
showing the spontaneous growth of baroclinic
eddies and describing the final statistical
steady state that occurs. Energetic analyses
and vorticity balances show the important rote
played by the eddies jn determining the charac-
ter of the oceanic general circulation.

Part II of this paper will discuss a variety
of experiments which explore the dependence
of results on the basic parameters and boundary
conditions governing the model. In particular
the dependence of results on wind stress
magnitude and distribution, lateral viscosity
coefficient, basin size, and boundary con-
ditions (free slip and no slip) will be
examined.

134

Holland, W. R. and L. B. Lin. 1975b. On
the generation of mesoscale eddies and
their contribution to the oceanic general
circulation. II: A parameter study. J.
Phys. Oceanogr. 5:658-669.

In this investigation the wind-driven ocean
circulation theories are extended to include
mesoscale eddies as an integral part of the
general circulation of the ocean. A two-layer
numerical model of ocean circulation in a
simple, rectangular basin driven by a steady
wind stress is used for this purpose. The
equations of motion are integrated as an initial
value problem until the solutions reach either
a steady state or, in the case of an ocean in
which eddies have appeared spontaneously as a
result of baroclinic instability, a statisti-
cally steady state.

Part I of this study discussed the formula-
tion of the numerical model and presented results
from a preliminary numerical experiment.
Energetic analyses showed that eddies result
from baroclinic instability during the spin-up
of the ocean from rest and that, in the final
statistically steady state, the eddy momentum
and buoyancy fluxes played 'an important role
in establishing the mean circulation. In the
particular case examined there, the region of
eddy generation was in the westward return flow
and not in the strong boundary jets.

In this part of the study, results from
ten additional experiments are examined to under-
stand, in a limited way, how eddy generation and
the resulting eddy statistics depend upon the
basic parameters describing the model ocean.

In particular, the dependence of results on
the coefficient of lateral viscosity, the wind
stress amplitude, the wind stress distribution
(one and two gyres), the basin size, and the
boundary conditions (slip and no-slip) are dis-
cussed. Results show a wide range of mode?
behavior under the conditions examined but the
conmon result is that the mean circulation of
eddying oceans is importantly altered, one
might even say largely determined, by the
statistical nature of the eddy field.

Hollman, R. 1970. The physical oceanography
of the New York Bight. Proc. Water Pollut.
Greater New York Area Symp. p. 2-12.

Hollman, R. 1973. Some features of the circula~
tion in the New York Bight. £0S Trans.
Amer. Geophys. Union 54(4) :302.


early June. The intensity of the thermocline increases and reaches a maximum
in mid-August to early September. As the surface waters continue to warm,
the thermocline deepens and increases in intensity. The warmer surface
waters then begin to mix downward increasing the bottom temperature. Maxi-
mum bottom temperatures are reached approximately one month after the surface
temperature has reached a maximum (Ketchum and Corwin, 1964). Cooler air
temperatures by this time have produced fall overturn which breaks down
thermal stratification and enhances vertical mixing.

The intensity of the thermocline varies as a function of wind and solar
heating. With an early spring onset of southerly winds and atmospheric
heating a strong thermocline can be set up reducing vertical mixing to near
zero. Added to this can be large freshwater runoff from the estuaries
creating large salinity differences further intensifying stratification.
Strong southerly winds can also provide a mechanism for invasion of warm
high-salinity slope water onto the shelf at mid-depths or along the bottom,
compensating for offshore transport in the surface layer. During the
winter when this occurs a weak thermohaline stratification appears with
slope water moving in along the bottom. During the summer, the warmer, more
saline water appears to move along the shelf into the vicinity of the 10 m

isobath (Boicourt and Hacker, 1976).

Slope Water

Wright (1976a) subdivided the slope water into three layers: surface,
permanent thermocline, and deep, based on thermal characteristics. The
surface water layer exists in the upper 200 m. where seasonal changes due
to surface warming and cooling and wind-mixing occur, and where shelf

water incursions occur to a depth of approximately 120 m. The annual

45


activity was relocated to the 106 mile toxic waste dumpsite (Interstate
Electronic Corp., 1978).

A report was prepared by EG&G Environmental Consultants for duPont
(EG&G, 1977) concerning the dispersion of the waste at the 35 mile site.
Their findings showed that during a September 1976 experiment, the thermal
stratification (evidenced by a well-defined thermocline at 10 m depth)
limited the vertical extent of the waste discharged. Measured iron con-
centrations and pH showed about a 5000:1 minimum dilution in the barge
wake after 15 minutes. Minimum dilution increased through time to 20,000:1
after 2 hours and to over 250,000:1 after 6 hours. Seawater pH was
lowered at the shallow depths above the observed thermocline due to the
acidic waste, but returned to ambient values after about 3 hours. Klemas
et al. (1977) observed several Edgemoore waste plumes in Landsat satellite
and aircraft data during both the stratified (summer) and unstratified
(winter) seasons. The plumes drifted generally south or southwest at
about 25-30 cm-sec-]. Drogue studies on the site showed a southwest
movement of about 25 cm+sec-] in the winter, while some drogues tended to
move north and northeast during the summer (Klemas et al.,- 1977). Most
important, however, were the higher droque speeds (as great as 100 cm-sec”!)
directed towards the southwest which were measured at the site during the
passage of an offshore low pressure storm system. During such events,
enhanced vertical wind mixing when coupled with the high advection rates
may greatly increase the dispersion of an acid waste plume relative to

the already high rates measured at the site.

Offshelf Sites
The only deep water offshelf dumpsite within the Middle Atlantic

Bight is the 106-Mile toxic waste dumpsite centered near 38°50'N, 72°15'W

74


of her results to variations in the data. This model could be used to
evaluate the most efficient use of data to provide good estimates of the

transport. This is not a predictive model.

Dissolved Oxygen Model

The modeling framework developed at Manhattan College has had wide
application and has recently been applied to the dissolved oxygen problem
in the New York Bight (O'Connor, Mancini and Guerriero, 1981; 0'Connor
and Mancini, 1979). Basically, their procedure is to use a model(s) of
the various mechanisms they feel are relevant as a focal point to organize
data, to extract water transport, and to calculate transport of constitu-
ents of concern. The model is then used to predict conditions under a
variety of scenarios. These results can then be used to evaluate the
various scenarios in some possible decision-making process.

This framework is heavily dependent on data for actual development
of the model, for determining water transports, and for calibrating the
coefficients in the model, but it makes efficient use of the data.

Various verification procedures have been developed for the model param-
eter studies to help the analyst determine the best coefficients based on
the available data (Thomann, 1980).

One of the strong points for this modeling framework is that pre-
dictions can be made assuming various physical scenarios. This framework
is also a good example of how a model can be used. to synthesize and evalu-
ate data. It is not unusual in this type of modeling framework that the
analyst finds that there is not sufficient information in the data to
differentiate alternative mechanisms that could be occurring. The analyst

can then propose measurement programs to generate the required data.

84


Gulf Stream Front

The Gulf Stream front is a narrow zone of abrupt horizontal change
in temperature and salinity caused by the strong velocity shear between
the weak, southwesterly flow in the slope water and the strong north-
eastward and eastward flow of the Gulf Stream. The front is continuous
off the east coast of North America and has been observed to depths of
2000 m. In the upper 400 m there are distinct differences in water
Masses across the front, between the cooler, less saline slope water and
the warmer, more saline Gulf Stream water. The front inclines downward
in the offshore direction.

Along its course, large perturbations develop in the Gulf Stream
front because of meandering of the Gulf Stream (Fig. 6). Hansen (1970)
described the Gulf Stream meandering as "quasi-geostrophic", comprised
of frontal waves which progress eastward with phase speeds of 5 to 10
cm.sec-1 and wave lengths of 200 to 400 km. The amplitude of the waves
at the surface typically increases toward the east almost linearly
downstream from Cape Hatteras, coursing a swath about 100 km wide off
Cape Hatteras to more than 300 km wide south of the Scotian Shelf
(Hansen, 1970). Current meter measurements made by Schmitz, et al. (1970)
indicated that the meanders extend to considerable depth (2,585 m).
Although the meandering of the front is usually limited to the slope
water region, on occasion meanders may penetrate to the shelf water
(Gotthardt and Potocsky, 1974).

The surface position of the Gulf Stream front has been monitored
from ship reports, airborne infrared data, bathythermographs, and satellite-
derived infrared imagery and shown in monthly maps since 1966 ("The Gulf

Stream Monthly Summary” and "Guifstream"). Since 1973 the U.S. Naval

39


Fisher, A. 1973, Environmental guide to the
Virginia Capes operating area, U.S. Naval
Oceanogr. Off. Spec. Publ. 211, 58 pp.

Fisher, A., Jr. 1972, Entrainment of shelf water
by the Gulf Stream northeast of Cape Hatteras.
J. Geophys. Res. 77: 3248-3255.

Entrainment of relatively cold low-salinity water
by the Gulf Stream and subsequent formation of a cold
filament adjacent to the northern edge of the Gulf
Stream were frequently observed during a series of
combined ship and aircraft surveys conducted north-
eastward of Cape Hatteras between October, 1968, and
May, 1969. Particularly well-defined entrainment was
observed during mid-May, 1969 when a band of surface
water 10 to 15 km wide and 40 meters thick was observed
to reach from the continental shelf to the northern
edge of the Gulf Stream. Transport. sgaward from the
outer shelf is of the magnitude 104 m3/sec. Failure
to observe entrainment during some of the flights
agrees with the discontinuous nature of the cold
filament adjacent to the northern edge.

Fitzgerald, J. and J. L. Chamberlin. 1981.
‘Anticyclonic warm core Gulf Stream eddies
off the northeastern United States during
1979. Annis biol., Copenh. 36:44-51.

Fitzgerald, J. and J. L. Chamberlin. In press.
Anticyclonic warm core and Gulf Stream
eddies off the northeastern United States
in 1980. Annis biol., Copenh.

Flagg, C. N. and R. C. Beardsley. 1978. On the
stability of the shelf water/slope water
front south of New England. J. Geophys.
Res. 83(C9):4623-4631.

The baroclinic stability of a Margules front
over steep topography is studied in an attempt
to explain some wavelike features observed on
the shelf water/slope water front south of New
England. During winter this front extends from
the bottom hear the 85 m isobath to the surface
with a typical mean slope of 2X 107*, with
a corresponding geostrophic shear of about
10 cm/s. A quasi-synoptic hydrographic survey
of the New England shelf made during March 1974
resolved a wavelike distortion of the front
characterized by a 80-km alongshelf wavelength.
The associated Rossby number based upon the
alongshelf wave number and the vertical shear
(Ro = k(aU)/2F) is <0.05, so that a perturbation
analysis using the semigeostrophic approximation
is possible. This approach allows the resulting
equations to be cast into an ordinary eigenvalue
problem which can be easily solved numerically.
The effect of increasing the bottom slope is to
destabilize some neutral modes and to stabilize
other modes that had been unstable over flat
topography. In general, however, the character-
istic e folding times of the unstable modes
increase dramatically from 2-5 days for flat
topography to greater than 50 days for realis-
tically steep topography. This rapid decrease
in growth rates with increasing bottom slope
implies that the observed wavelike features on
the front must be generated by some mechanism
other than local baroclinic instability. Once
they are generated, the observed features may
propagate as essentially stable frontal wave
modes. We note, however, that the front would
be quite unstable if it was located over flat
topography. This may help explain why persistent
fronts of this type appear te be found near the
shelf break.

125

Flier], G..R. 1979. A simple mode? for the
structure of warm and cold core rings.
J. Geophys. Res. 84(C2):781-786.

We consider the simplest model describing
the shape and strength of warm and cold core
rings. The Coriolis parameter is taken to be
constant. The flows are strong enough so that
the interface betweem the two fluids rises to
the surface. We describe the velocity and
interface depth profiles and compare the model
to field data.

Flierl, G. R. 1980. Simple models of waste
disposal in a gyre circulation... Presentation
at the 2nd International Ocean Disposal
Symposium.

Flier], G. 1981. Motion and dispersion of dumped
material by large amplitude eddies. P. 125:
(abstract). In: Program and Abstracts -
Third International Ocean Disposal Symp.
Woods Hole Oceanographic Inst., Woods
Hote, MA. Oct. 12-16, 1981, 156 pp.

Ford, W. L., J. R. Leonard and R. E, Banks.
1952. On the nature, occurrence and origin
of cold Tow salinity water along the edoe
of the Gulf Stream, J. Mar, Res. 11(3):
281-293,

Ford, W. L. and A. R, Miller. 1952. The surface
layer of the Gulf Stream and adjacent waters.
J. Mar, Res. 11(3):267-280.

Freeland, G. L., G, Han, W. L. Stubblefield,
D. J. P. Swift, P. E. Gadd and J. W.
Lavelle. 1976. Morphologic evolution
and coastal sand transport, New York and
New Jersey shelf. An. Soc. Limnol.
Oceanogr, Spec. Symp. 2:69-89.

* A geological history of the continental
shelf is presented in this paper along with quanti-
tative estimates of sediment transport. The
Holocene transgression of tide dominated sedi-
mentation at estuary mouths and sand transport
patterns that develop along the adjacent shoreface
and inner shelf are discussed. Real-time studies
of fluid motion and substrate responses are made.
Reports on analysis and studies of sand transport
yield fragmented reports and many more questions
than initially realized.

Freeland, G. L., D. J. Stanley,-D. Lambert and
D. J. P. Swift. 1981. The Hudson Shelf
Valley: Its role in shelf sediment
transport. In: Sedimentary Dynamics of
Continental Shelves. C. E. Nittrouer,
{ed.). Elsevier, NY, p. 399-427.


Beardsley, R. C. and J. Hart. 1978. A simple
theoretical model for the flow of an estuary
onto a continental shelf. J. Geophys. Res.
83(C2):873-883.

A simple theoretical model is developed to
describe the steady flow of an estuary onto an
adjacent continental shelf. A two-layer density
stratification is assumed for the shelf water,
and the fluid motion is driven by the positive
(upper layer) and negative (Tower Tayer) mass
fluxes associated with a pair of point_sources
located at the mouth of the estuary. The dynamics
are linear and include the effects of Coriolis
acceleration, turbulent friction, and bottom
topography. ‘Analytic solutions for the one-layer
single-source problem are found for two special
depth profiles. A boundary layer solution is
found for the power law depth profile h(y) =
ayk, and a global solution is found for the log
Taw profile hy) = Mo(1 + tn (y/ty)} for small
a <<l. Both solutions indicate tht the far-
Field flow is asymmetrically concentrated toward
the right-hand coast in the northern hemisphere,
a consequence of the basic balance between topog-
raphic vortex stretching and bottom friction.
This mechanism also applies when a constant
alongshore current is present. In the two-layer
case the flow in the upper layer generally tends
to be concentrated toward the left-hand coast,
since the upper fluid feels (1) the interface and
not the bottom topography and (2) the interfacial
drag exerted by the lower fluid toward the right-
hand coast. A brief comparison is made between
model predictions and observations for the
Hudson and Chesapeake Bay estuaries.

Beardsley, R. C., H. Mofjeld, M. Wimbush, C. N. Flagg,
and J. A, Vermersch, Jr. 1977. Ocean tides and
weather-induced bottom pressure fluctuations in
the Middle Atlantic Bight. J. Geophys. Res.
82(21):3175-3182.

Five bottom pressure gages were deployed in the
Middle Atlantic Bight during the late winter of 1974.
Analysis of the resulting pressure series and neighbor-
ing coastal tide gage series shows that tides are the
dominant pressure signal in this section of the con-
tinental shelf. Most of the remaining pressure
fluctuations appear to be forced by meteorological
transients. During March 21, 1974, a developing
cyclone moving up the coast excited a coherent group
of sea level oscillations with characteristic periods
of 5-7 hours, which are interpreted here as coastal-
trapped edge waves. Spectra of the nontidal pressure
series are red, however; most of the non-tidal
variability is caused by lower-frequency (subtidal)
components. The subsurface pressure (SSP) fluctuations
do appear coherent over the spatial extent of the
array in the most energetic subtidal frequency bands,
and estimates made of the relative horizontal SSP
gradients indicate that cross-shelf gradient varia-
tions are significantly larger than alongshore
gradient variations. Some consequences of these
large weather-induced gradient fluctuations on the
shelf circulation are discussed.

109

Beardsley, R. C. and C. D. Winant.. 1979. On
the mean circulation in the Mid-Atlantic
Bight. J. Phys. Oceanogr. 9:612-619.

Two possible mechanisms which may.drive the
observed mean alongshelf flow in the Mid-Atlantic
Bight are described. Runoff from concentrated
sources could conceivably force this flow; however,
the one-layer homogeneous model results of
Csanady (1978) and Beardsley and Hart (1978)
imply that the observed shelf flow is not driven
by runoff alone. On the other hand, the Semtner
and Mintz (1977) numerical model of the North
Atlantic strongly suggests that the shelf circula-
tion is just a boundary Tayer component of the
ocean circulation and thus driven by the large-
scale wind stress and heat flux distributions.
This model result supports Csanady's (1978)
conclusion that the physical mechanism which
creates the alongshelf pressure gradient thought
to drive the alongshelf flow must be of oceanic
origin.

Behringer, D., L. Reiger, and H. Stommel. 1979.
Thermal feedback on wind-stress as a con-
tributing cause of the Gulf Stream. J. Mar.
Res. 37:699-709.

A simple model is used to explore a feedback
mechanism which may be significant in the forma-
tion of the Gulf Stream, The feedback operates
through the drag coefficient which is a function
of the sea-air temperature difference. The mode}
is divided into interior and western boundary
regions which are overlaid by an atmosphere with
a constant meridional temperature gradient. The
model predicts the interior sea-air temperature
difference which determines, in sequence, the
enhancement of the basic wind-stress distribution,
the interior Sverdrup velocity, and the zonal
velocity between the interior and the western
boundary regions. All variables are functions
of latitude only. Calculations for a two gyre
ocean demonstrate the ability of the feedback
mechanism to produce a “Gulf Stream" without
higher order dynamics.

Bennett, John R. and Bruce A. Magnel?. 1979.
‘A dynamical analysis of currents near the
New Jersey coast. J. Geoph. Res. 84(C3):
1165-1175.

A numerical mode? is used to analyze currents
measured on the continental shelf near the shore of
New Jersey. The model neglects Tongshore varia-
tions of current and all variations of density,
but includes inertial accelerations and a non-
linear eddy viscosity. Local wind stress, sea
level changes, and a constant longshore pressure
gradient are the forcing terms. The model
successfully reproduces most of the current
variance; however, the predicted currents do not
exhibit the dominant 4-hour response time of the
observed currents, and the model sometimes
misses energetic current events. These differ
ences are ascribed to three-dimensional setup
effects elsewhere in the New York Bight.


Chuang. W. S. and D. P. Wang. 1981. Effects
of density front on the generation and
Propagation of internal tides. J. Phys.
Oceanogr. 11:1357-1374.

A numerical model is developed to study
the internal tidal motion on the continental
margin. The system includes irregular bottom
topography and a horizontal density stratifi-
cation maintained by a mean geostrophic current.
Both the propagation and generation processes are
examined.

In the propagation process, the topographic
effect alone will scatter a significant part of
the incident wave energy into higher modes,
resulting in a beamlike structure for the trans-
mitted wave. For a density front over a flat
bottom, energy in the transmitted waves remains
largely in the original wave mode, though the
wave Tength, and hence wave amplitude, varies with
local density stratification. When the density
front is located over a sloping bottom, the topo-
graphic effect is reduced, whereas the frontal
effect is not affected. Thus, scattering into
higher modes becomes more restricted.

In the generation process, internal tides are
produced in the upper and lower parts of the slope
region due to the interaction between surface
tides and bottom topography. With the presence
of a density front, internal tide energy also can
be derived from the surface frontal Tayer. In
addition, the topographic effect will be modified
by the front. The net effect is destructive
(constructive) when the isopycnals tilt upward
in the shoreward (seaward) direction.

These results indicate that on the continental
margin, the density front has strong effects on
the generation and propagation of internal tides,
particularly when the density front is located
above the continental slope. Since the internal
tide provides an important energy source for
mixing on the shelf, the density fronts will
have a storng effect on the mixing processes.

Clarke, G. L. 1938. Seasonal changes in the
‘intensity of submarine illumination off
Woods Hole. Ecology 19: 89-106.

Clarke, G. L., &. L. Pierce and D. F. Bumpus. 1943.
The distribution and reproduction of Sagitt
elegans on Georges Bank in relation to hy
graphic conditions. Biol. Bull. 85: 201-226.

Cohen, E. B. and W. R. Wright. 1978.
Changes in the plankton on Georges Bank
in relation to the physical and chemical
environment during 1975-76. Int. Counc.
Expl. Sea paper.C.M. 1978/L:27.

Nine cruises were made on Georges Bank between
September 1975 and December 1976 during which chloro-
phy1l, nutrients and planktonic biomass were measur~
ed along with temperature, salinity and dissolved
oxygen, Primary production was measured on most
of the cruises. Data from these cruises are pre-
sented in vertical plots to show the relation be-
‘tween physical and biological variables. Pri-
mary production is calculated to be on the order
of 400 to 500 gm C m-2y-1. After an initial
increase in the spring primary production appears
to remain at high levels with no evidence of a
decrease in sumer through fall. The high pro-
duction seems to be maintained by mixing on top
of Georges Bank and by transport of nutrient-rich
deeper water toward the Bank along both the
northem and southern edges. Observations that
are closer in both space and time will be re-
quired to confirm this hypotheses.

Colton, John. 8., Jr. 1968. Recent trends in subsurface
temperatures in the Gulf of Maine and continuous

waters. J. Fish. Res, Bd. Canada. 25(11):2427-2437.

A comparison was made of 1955-60 and 1961-66 monthly
mean 200-m temperatures in eight 1-degree quadrangle areas
in the Gulf of Maine and along the Continental Slope be-
tween Nova Scotia and Long Island. Temperatures were
appreciably lower in all areas during the latter period.
The subsurface temperature trends paralleled trends in
surface temperatures previously documented. The distri-
bution of temperature at 200 m along the edge of the
Continental Shelf during March, May-June, and September

1965 and 1966 and the distribution of temperature, salinity,
and dissolved oxygen on sections made across the Continen-

tal Shelf in September 1954, 1965, and 1966 showed that
the cooling and warming trends are accompanied by changes
in the composition of the subsurface water. Cold years
occur when Slope Water is displaced or modified by
Coastal Water of Labrador origin. Warm years occur when
Slope Water borders upon the 200-m isobath and the ratio
of Coastal to Central Atlantic Water is low.

Colton, J. B., R. Marak, S. Nickerson and R.
Stoddard, 1968. Physical,chemical and
biological observations on the continental
shelf, Nova Scotia to Long Island, 1944-66.
U.S. Fish and Wildlife Service Data Report
No. 23. 189 pp.

Colton, John B. and Ruth R. Stoddard. 1972. Average
monthly sea water temperatures - Nova Scotia
to Long Island, 1940-1959. Folio 21 - Serial
Atlas of the Marine Environment, American
Geographical Society.

Average monthly temperatures at the surface, 10, 20,
30, 40, 50, 75 and 100 m. Also monthly temperature pro-
files at one-degree (longitude) intervals. Covers Gulf
of Maine, Georges Bank and environs between 64° and 72°W,
north of 39°N.

Colton, John B. and Ruth R. Stoddard. 1973.
Bottom water temperatures on the con-
tinental shelf, Nova Scotia to New
versey, NOAA Tech. Rept. NMFS CIRC-
376. 85 pp.

Mean monthly and annual maximum and
minimum bottom water temperatures, based
on data collected in 1940-66, portrayed on
15 maps.

Colton, J. B. and R. F. Temple. 1961. The enigma
of Georges Bank spawning. Limnol. and
Oceanog. 6(3) :280-291.

The drift of bottles and transponding drift buoys
over the Georges Bank area show that, with the exception.
of midsummer when the Georges eddy i$ most pronounced
and southerly winds predominate, surface drift is off-
shore in the direction of the slope water band. In-
dications are that the currents below the surface move
at a slower rate than at the surface, but in a similar
direction. The effects of offshore drift, time and
location of spawning, vertical distribution of eggs
and larvae, and length of pelagic life on the dispersal
and survival of eggs, larvae, and juveniles of com-
mercially important foodfishes are discussed. It
appears from observations on haddock and herring that
under average conditions most fish eggs and larvae are
carried away from Georges Bank and lost to the fishery,
that only under unusual hydrographic conditions are the
eggs and larvae retained ‘in the area, and that the year
class strength of the various species inhabiting Georges
Bank is dependent in part upon non-tidal drift.

118



Doyle, B. E. and R. E. Wilson. 1978. Lateral
dynamic balance in the Sandy Hook-Rockaway
Point transect. Estuarine & Coastal Mar.
Sci. 6:165-174.

Currents associated with the residual non-
tidal flow through the Sandy Hook to Rockaway
Point transect exhibit considerable vertical
and lateral structure including a two-layer
estuarine flow pattern over much of the transect
and inflow to New York harbor. at al] depths
near Rockaway Point. To determine the relative
importance of different dynamic processes in
maintaining this structure, the nontidal lateral
momentum balance in the transect has been examined
using current meter and hydrographic data from the
1952 and 1958-1959 U.S. Coast and Geodetic Survey
field studies in New York Harbor. Results suggest
that over the entire transect the lateral pressure
gradient force balances the sum of the centrifugal
force associated with the oscillating tidal flow
and the Coriolis force due to the nontidal flow
normal to the transect. This balance is maintained
without significant contribution from turbulent
shear stresses. Over much of the transect the
primary balance is between the lateral pressure
gradient force and the centrifugal force.

Drake, D. £. 1974, Suspended particulate
matter in the New York Bight Apex:
September-November 1973. NOAA Tech.
Rept., ERL 318 - MESA 1.

Drake, D. E. 1977. Suspended particulate
matter in the New York Bight Apex, Fall
1973 Sedim. Petrol. 47(1):209-228.

Duedal?, I. W., T. A. Nelsen, T. A. Johnson,
J. 'R. Glasgow and J. R. Proni. 1977.
Quantitative mapping of suspended solids
in wastewater sludge plumes in the New
York Bight apex. J. Water Pollution
Control Fed. 49:2063-2073.

* On September 22, 1975, three wastewater
sludge dumps and their plumes were monitored by
air remote sensing and surface vessels, the NOAA
Ship KELEZ and the SUNY vessel ONRUST. Remote
data was collected by a multispectral scanner,
multispectral photograph, and a mapping camera.
Surface water samples and acoustic profiling

data are presented in another report. Results
show that calibrated regression equations relate
to remotely sensed data and to sea-truth measure-
ment and can be used to provide maps of synoptic
distributions of water quality parameters
associated with ocean disposal of wastewater
sludge.

Duedall, I. W., S. A. Oakley, J. J, Parker and
R. Proni. 1981. Sewage sludge tracking
in the New York Bight (Abstract). Third
International Ocean Disposal Symposium,
Woods Hole Oceanographic Inst., Woods Hole,
MA. Oct. 12-16, 1987.

123

Duedal1, I. W., H. 8. O'Connor, J. H. Parker,
R. E. Wilson and A. Robbins. 1977.
The abundances, distribution and flux of
nutrients and chlorophy!] a in the New
York Bight apex. Est. & Coast. Mar. Sci.
5:81-105.

Tidal, spatial and seasonal changes in
salinity, temperature and concentrations of
ammonium, nitrite, nitrate, phosphate, silicic
acid, chlorophytl a and suspended matter in the
waters between Sandy Hook, New Jersey and Rockaway
Point, New York, were measured during five cruises
which took place between November 1973 and June
1974. Over this period concentrations of
nutrients and chlorophy!l a were much greater
than those found in the adjacent coastal waters.
The main source of the ammonium, nitrite and
phosphate is sewage effluent which is discharged
into the waters surrounding the New York metro-
politan region; nitrate comes mainly from the
Hudson River and silicic acid is discharged in
Jarge amounts from river and sewage sources.

The largest tidal variation in salinity and
nutrient and chlorophyl? a concentrations occurs
near Sandy Hook where the Hudson River discharge
has the greatest influence. Near Rockaway
Point, nutrient and chlorophyl] a concentrations
are generally lower and salinities higher than
those observed near Sandy Hook because of the
inflow of Bight water by non-tidal currents.
During the spring freshet nutrient concentrations,
especially ammonium, are low along the transect due
to (1) dilution by the spring freshet and (2)
utilization by the abundant phytoplankton.

Flux calculations for the June observations
indicate that most of the nutrients and chloro-
phy] a are being transported from the lower
Hudson Estuary into the New York Bight apex.

EG&G. 1975. Summary of oceanographic
observations in New Jersey coastal waters
near 39°28'N latitude and 74°15'W longitude
during the period May 1973 through April
1974. Rep. B-4424. E G & G Environ.
Consult., Waltham, MA.

EG&G Environmental Consultants. 1977.
Measurements of the dispersion of barged
waste near 38°33'N latitude and 74°20'W

longitude. Unpublished report submitted
to E. I. duPont deNemours & Co., Edgemoore,
Delaware.

EG&G. 1978. Intersection of a Gulf Stream

eddy with Georges Bank. New England Outer
Continental Shelf Physical Oceanography
Program, Appendix D of 8th quarterly
Progress Report to U.S. Dept. Int., Bur.
Land Management, V:D-1 to D-56.

Eittreim, S., M. Ewing and E. M. Thorndike.
1969. Suspended matter along the continental
margin of the North American Basin. Deep
Sea Res. 16:613-624.



Milliman, J. D., M. H. Bothner and C. M. Parmenter,
1980. Seston in New England Shelf and
Slope Waters 1976-1977. 171 to 173. In:
Environmental Geology Studies in the
Georges Bank Area, U.S. New England Atlantic
Quter Continental Shelf 1975-1977 (J. M.
Aaron, ed.). Final report submitted to
the U.S. Bur. of Land Management.

Mizenko, D, and J. L, Chamberlin, 1979a, Anti-
cyclonic Gulf Stream eddies off the north-
eastern United States during 1976. In:
Ocean variability in the U.S, Fishery
Conservation Zone, 1976, J, 8, Goulet, dr,
and E, D. Haynes féds.), NOAA Tech Rep.
NMFS CIRC 427 :259-280.

Mizenko, D. and J. L. Chamberlin. 1979b.
Gulf Stream anticyclonic eddies (warm
core rings) off the northeastern United
States during 1977. Annales Biologiaues,
Vol. 34:39-44.

Mizenko, D. and J. L. Chamberlin. 1981.
Stream anticyclonic eddies and shelf
water at 106 mile site during 1977. In:
Assessment Report on the Effects of Waste
Dumping in 106 Mile Ocean Waste Disposal
Site. NOAA Dumpsite Eval. Rep. 81-1.
U.S. Dept. of Commerce, Pub. P. 207-232.

Gulf

Mooers, Christopher, N. K., R. W. Garvine and
W. W. Martin. 1979. Summertime synoptic
variability of the Middle Atlantic sheTf/
slope water front. J. Geophys. Res. 84(C8):
4837-4853.

A quasi-synoptic study of the shelf water/slope
water front off New Jersey, Delaware, and Maryland
in mid-July 1977 revealed an isolated body of very
cold (<6°C) water in the near bottom ‘cold pool'.
Its volume at least halved over 10 days during which
nearby shelf waters were perturbed by two anticyclonic
(warm core) eddies located over the continental slope.
Water colder than 6°C lay along the bottom between the
80- and 100-m isobaths and was about 30 m thick. The
seaward edge of the cold pool (here denoted as.
colder than 8°C) marked the inshore boundary of the
shelf water/slope water subsurface temperature front
with 10°C variations per 2-20 km, depending upon
alongshelf location. The thermocline underwent
large displacements and deformations over 10 days,
indicative of vigorous upwelling and downwel1ing
and large potential vorticity changes at the
shelf break. The dominant scales of variability
(or correlation scales) in the thermal fields were
30 km alongshelf, 10 km cross shelf, and 1- to
perhaps 20 days. (The internal radius of deforma-
tion on the outer shelf is about 15-25 km). There
was substantial vertical structure on the scale
of 10 mor less. A surface convergence zone
coincided with a surface roughness bank (‘tide
rip') near the shelf break, and internal gravity
wave activity seemed intense there too. Two
independent estimates of vertical velocity at the
shelf break suggested values of about 10-2 cm/s,
one for a time scale of a week or longer and the
other for a time scale of at least a few hours,
Over Wilmington Canyon a large ‘lip’ of cold
pool intruded into the slope water along the
southwestern side of the Canyon, perhaps under-
going entrainment and ‘calving’ by an anticyclonic
eddy located over the slope. There was further
evidence of offshore entrainment throughout the
water column between the two eddies.

147

Movers, C. N. K., J. Fernandez-Partagas, and
J. F. Price. 1976. Meteorological forcing
fields of the New York Bight. University
of Miami Tech, Report U-RSMAS, TR-76-2,

PP.

* This paper is a report on meteorological

forcing in the New York Bight. The study involved

analysis of cyclones in the area at the time

to determine their effect on surface pressure,

temperature, dew point, and wind information.

Precipitation, water flux and wind stress curl

and divergence were some of the parameters studied.
Data collected is presented throughout the

paper in the form of graphs and mathematical

equations.

Morel, F. M. M. and K. J. Farley. 1981. The
importance of coagulation in the sedimenta-
tion of waste particles in receiving waters
(abstract). Program and Abstracts, Third
International Ocean Disposal Symposium.
Woods Hole Oceanographic Inst., Woods
Hole, MA. Oct. 12-16, 1987.

Morgan, Charles W., and Joseph M. Bishop. 1977. An
example of Guif Stream eddy-induced water ex-
change in the Mid-Atlantic Bight. J. Phys.
Oceanogr. Vol. 7, pp. 472-479.

* Data and observations for this study were
collected froma cruise by the USCGC EVERGREEN
in August of 1974.

The eddy was observed about 110 nm southeast
of Cape May.

From the temperature and salinity data taken
and current studies done while on the cruise,
it was suggested that eddies may be responsible
for an important portion of the mixing of shelf
water with the slope water region in the Mid-
Atlantic Bight.

Norton, R. W. 1970. Suspended sediment distribu-
tion in Narragansett Bay and Rhode Island
Sound. Southeast Meet. Geol. Soc. Amer.

GSA Memoir Symp. on Estuaries.


Ou, H. W. and R. C. Beardsley. 1980. On the
propagation of free topographic Rossby waves
near continental margins. Part 2: Numerical
model. J. Phys. Oceanogr. 10:1323-1339.

Ou (1980, Part I) presented analytical solutions
of free topographic Rossby waves propagating in an
infinite wedge filled with a uniformly stratified
fluid. We present here in Part 2 a numerical model
incorporating more realistic topography and bottom
friction to simulate the propagation of these waves
across continental margins. Although the analytical
solutions in a wedge can explain many of the wave
properties observed in our numerical model, new
features are introduced that have practical impor-
tance. It is found that the replacement of the
apex by a finite nonreflecting shelf introduces at
the shelf break an antinode in the pressure field,
causing the kinetic energy to drop rapidly across
the shelf break onto the shelf. It is also found
that the baroclinic fringe waves excited near the
slope/rise junction can cause an amphidromic
point to form for shorter waves and reverse the
direction of phase propagation above it. This
changes the sign of the Reynolds stress locally and
might have important implications on the mean flow
structure generated by these waves. The baroclinic
fringe waves also cause an offshore heat flux over
the continental rise as in contrast to the onshore
heat flux generated over the slope region due to
the rigid upper surface. This heat flux divergence
near the slope/rise junction can obviously contribute
to a mean sinking motion there, accompanied by
upwelling on both sides of it.’ Friction, however,
generates an offshore heat flux near the bottom,
and complicates this heat flux distribution. The
model predictions are compared with the current and
temperature data obtained south of New England
during 1976, The comparisons are generally consistent,
suggesting that topographic Rossby wave dynamics
play an important role for the low-frequency
motions over the continental rise and slope.

Qu, H. W., R. C. Beardsley, D. Mayer, W. C. Boicourt
and B. Butman. 1981. An analysis of subtidal
and current fluctuations in the Middle Atlantic
Bight. J. Phys. Oceanogr. 11(10):1383-1392.

Subtidal current fluctuations in the Middle
Atlantic Bight are examined from current-meter data
collected in 1975 and 1976. Spectral analysis provides
evidence for both locally wind-forced response and
free waves that propagate downshelf which are not
correlated with the local wind. A simple empirical
mode] has been construcéed to fit two linearly
independent plane waves to the observed current
spectra. Application of the model to the current
data obtained at a pair of stations in the New York
Bight during the period of 26 October 1975 to
4 April 1976 indicates that the two waves propagate
in opposite directions along the coast, and with the
additional evidence from rotary-coefficient calcu-
lations, it is suggested that they correspond to the
forced and free waves speculated upon earlier.

The noise level is a free parameter in the model

and is determined by adjusting the phase speed of the
forced wave to the translation speed of the observed
wind field. This gives a 526 km day-! phase speed
for the free wave, and the forced wave, free wave
and noise compose~41, 39 and 20% of the total
variance,

151

Ou, H.W. and R. Houghton. 1981. A note on
the sunmer progression of the cold pool
temperature in the Middle Atlantic Bight.
Unpub]. Manus. Lamont-Doherty Geological
Observatory, Palisades, NY.

Pape, Edwin H. III, 1981. A drifter study of the
Lagranian mean circulation of Delaware Bay and
adjacent shelf waters. Master's thesis, Uni-
versity of Delaware. Del - SG-18-81. Delaware
Sea Grant College Program, Newark, Delaware 19711.

To document the Lagrangain mean circulation of
Delaware Bay and adjacent shelf waters a series of
nine deployments of surface and seabed current drif-
ters was made, The study area, roughly 50 km up
the Bay to 50 km offshore, was chosen to examine the
exchange of water between estuary and shelf. Each
deployment involved 28 stations and about 1000
drifters. Use of aircraft provided @ synoptic re-
ease.

The presence of classical estuarine circulation
in Delaware Bay can be inferred from maps of the
apparent drifter trajectories, The seaward surface
residual flow in the Bay is directed towards the
Delaware shore, consistent with Coriolis effects,
while the bottom residual flow moves upstream in
the deep channels of the Bay and then spreads la-
terally onto the adjacent shallower areas on both
sides. The estuarine circulation extends onto the
adjacent shelf. The surface residual motion on
the shelf is generally toward the south, although
it can reverse and flow northward while the bot-
tom residual currents converge on the Bay mouth.

Vector maps of mean speed and direction of
the residual circulation, with 95% confidence
intervals, show a coherent flow pattern over the
study area during the period studied. The speed
of the residual currents on the shelf is con-
sistently faster than that in the Bay. However,
over the entire study area, the surface resi-
dual circulation is an order of magnitude faster
than the bottom circulation. Both surface and
bottom current speeds in the Bay are slower than
those observed in other estuaries, and currents
on the shelf and slower than previously reported
for the Middle Atlantic Bight.

Wind and river conditions during the study
were not characteristic of their long-term
means. Consequently, it was not practical to
Present residual curculation patterns corresponding
to seasonal periods in wind and river runoff,
However, the return percentages suggest that off-
shore surface flow and onshore bottom flow intensify
in the second half of the calendar year.

Although river flow shows little correlation
with the residual circulation, the wind record
explains much of the variance in drifter movement.
In general, offshore winds drive surface water
downstrean/offshore and bottom water upsteeam/--
onshore in a simple two layer flow. This pattern
reverses for onshore wind. Enough of the variance
in drifter movements is left unexplained, however,
that other forcing, such as tidal rectification,
should be considered.

4


° mC
a

08

NOAA Technical Memorandum NMFS-F/NEC-17

This TM series is used for dacumentation and timely communication of
Preliminary results, interim reports, or special purpose information, and

pe MOSPHe5 has not received complete formal review, editorial control, or detailed
editing.

rs Northeast Monitoring Program
NEMP IV 82 F 0004

Summary of the Physical Oceanographic
Processes and Features
Pertinent to Pollution Distribution
in the Coastal and Offshore Waters
of the Northeastern United States,
Virginia to Maine

Merton C. Ingham’, Editor
Reed S. Armstrong!, J. Lockwood Chamberlin’, Steven K. Cook’,
David G. Mountain2, Ronald J. Schlitz2, James P. Thomas3,
James J. Bisagni4, John F. Paul5, and Catherine E. Warsh&

‘Atlantic Environmental Group, National Marine Fisheries Serv., Narragansett, RI 02882
2Woods Hole Lab., National Marine Fisheries Serv., Woods Hole, MA 02543
3Sandy Hook Lab., National Marine Fisheries Serv., Highlands, NJ 07732

«Applied Science Associates, Inc., Wakefield, RI 02879
sEnvironmental Research Lab., Environmental Protection Agency, Narragansett, R! 02882

6Ocean Pollution Monitoring Group, National Ocean Survey, Rockville, MD 20852

U.S. DEPARTMENT OF COMMERCE

Malcolm Baldridge, Secretary

National Oceanic and Atmospheric Administration
John V. Byrne, Administrator

National Marine Fisheries Service
William G. Gordon, Assistant Administrator tor Fisheries

Northeast Fisheries Center

Woods Hole, Massachusetts

December 1982


Koh, Robert C. Y. and Y. C. Chang. 1973.
Mathematical model for barged ocean dis-
posal of wastes. Environmental Protection
Technology Series EPA - 660/2-73029.
December 1973. 584 pp.

Kohn, D. and G. T. Rowe (1977). Dispersion of
two liquid industrial wastes dumped at Deep-
water Dumpsite 106, off the coast of New
Jersey, USA, Final Report, DWD 106 Large
Scale Dumping Study, NOAA, Rockville, MD.

Kuo, A. Y., E. P. Ruzecki, and C. S. Fang. 1976.
The effects of the Agnes flood on the sali-
nity structure of the lower Chesapeake Bay
and contiguous waters. In: The effects of
tropical Storm Agnes on the Chesapeake Bay
estuarine system, Chesapeake Research
Consortium, Ind. Publ. 54, The Johns Hopkins
University Press, Baltimore, Maryland.

Kupferman, Stuart L., and N. Garfield. 1977.
Transport of low-salinity water at the slope
water-Gulf Stream boundary. J. Geophys. Res.
82(24):3481-3486.

* — The author provides descriptive analysis of
temperature and salinity data from two cruises of

the RV EASTWARD (E-198-72, 30 October-05 November,

1972; E-GA-74, 23-30 May 1974) between Delaware Bay,
Delaware and Cape Hatteras, North Carolina across

the shelf and into the Gulf Stream. Two unconnected
bands of shelf water were found entrained in the Guif
Stream, one at the surface and one about the 100 m
depth. Transport volume of shelf water by the entrained
band process is estimated at 16,000 cubic meters/s.

laevastu, T. and R. Callaway. 1974. Computa~
tion of tides, currents, and dispersal of
pollutants in'the New York Bight from
Block Island to Atlantic City with large
grid size, single and two-layer hydro-
dynamical-numerical models. ENV PRED
RSCH FAC Tech, Note No. 4-74. Environ-
mental Prediction Research Facility, Naval
Postgraduate School, Monterey, CA $3940.

This report describes the results of the
application of Hydrodynamical-Numerical (HN)
models to New York Bight. The results of
computer runs with a large, two-open boundary,
single-layer model, as well as with a two-
layer model for the same area, are presented.
Many of the. problems in the application of
these models are connected with the treatment
of the open boundaries. The Environmental Pre-
diction Research Facility (EPRF) has found a
few satisfactory methods for the treatment of
these boundaries, some of which are briefly
mentioned in this report. The method is
further described in Part 2 of the report series
where the two-layer model is documentsd (see
references).

Vertification of the New York Bight models
is very brief, due to scarcity of proper
observations. However, the models have been
verified in other applications, to the extent
that they are considered to be ready for
operational and real-time use. It could be
mentioned that a 3-layer version of the models
have now been applied at EPRF to larger open
ocean areas with considerable success. The
experiences from these applications have been
indirectly used in this work and are available
to EPA.

a

Laevastu, T., J. Harding, kK. Rabe and S. Larson.
1976. Ocean-atmosphere interactions off
the northeast coast of North America.

Am. Soc. Limnol. Oceanogr. Spec. Symp.
Vol. 2:35-43,

The New York Bight-Middle Atlantic continental
shelf region is typical of midlatitude continental
east coast areas in the intense sea-air interaction
occurring during late autumn and winter. During
these seasons dry but cool air moving over warm
coastal water takes up a considerable amount
of heat and moisture (latent heat). The daily
uptake near the coast can exceed 0.5 9 of water
per cm2 on a monthly mean basis.

The response of the surface layers of the
atmosphere to the properties of the sea surface
is relatively rapid so that quasi-equilibrium
conditions are established after surface air
has traveled about 6 h over water.

The main consequences of this large heat
and moisture uptake on the atmosphere are deep-
ening of lows that pass the coastline and
frequent cyclogenesis off the coast. As the
heat and moisture are transported upward, a
trough forms at the 850-mb level. A thermally
driven cyclonic surface wind component is
created along the coast, but it often escapes
the attention of synoptic weather analysts.

The main effect of the atmosphere on the
ocean is rapid cooling of already cool coastal
waters during autumn and winter, resulting in
increases in thermocline depth. The coastal
southerly current is influenced by the surface
cyclonic wind component.

Lambert, R. 8. 1974. Small-scale dissolved
oxygen variations and the dynamics of Gulf
Stream eddies. Deep-Sea Res. 21:529-546.

Lauzier, L. M. 1967. Bottom residual drift
on the Continental Shelf area of the
Canadian Atlantic Coast. J. Fish. Res.
Bd. Canada 24:1845-1859.

Lavelle, J. W., T. L. Clarke, G. H. Keller.
1975. Possible bottom current response
to surface winds in the Hudson Shelf
Channel. J. Geophys. Res. 80:1953-1956.

* A brief report which discusses current
studies done in the Hudson Shelf Channel during
the summer of 1973.

Current measurements were taken over an
11 day period. Wind data was taken at "Ambrose
Tower some 34 km north-northwest of the site,
and at Barnegat Light, New Jersey, some 56 km
south-southwest of the site."

Although data collection occurred over a
relatively short period of time, it was concluded
from the observations that “there is reason to
suggest a correlation between flow in the axis
of the Hudson Shelf Channel and the prevailing
surface winds. During the summer period, winds
which blow onshore (south-southwest or south)
seem to produce down-channel flow, while winds
blowing offshore (west or northwest) appear to
cause a current reversed and net up-channel
current".



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102


in other long term sea bed drifter studies. They also noted, however,

a strong near-bottom estuarine-like circulation into Long Island Sound

and New York Harbor at 2 cm-secul. They found an apparent divergence

along the Hudson Shelf Valley where east of the valley bottom drift was
northward while west of the valley more westward bottom drift was observed.
Bottom drifter releases during April 1979-March 1980 reported by Pape (1981)
on the continental shelf inthe vicinity of Delaware Bay showed predominant-
ly onshore movement, strongly convergent on the Bay mouth.

Long-term near-bottom currents were studied in the Hudson Shelf Valley
and Canyon system by Keller et al. (1973) and Nelsen et al. (1978). Current
meter measurements showed flow reversals up and down canyon with velocities
of 8-15 cm-sec-1, with a maximum of 27 cm-sec7! in the upper central portion
of the canyon. Sediment texture and organic carbon content of the sediments,
however, indicate a long-term down canyon (seaward) transport of fines to
the continental rise. Nelsen et al. (1978) concluded from current meter
data and wind records that upchannel near-bottom flow was related to
westerly winds driving surface waters seaward during the winter, while
during the summer seaward near-bottom flow prevailed.

Biscaye and Olsen (1976) measured suspended particulate concentrations
in the New York Bight and found local resuspension of fine bottom sediments
due to erosional currents. These resuspended sediments were limited to
near-bottom waters during the stratified seasons due to limited vertical
mixing across the pycnocline.

Simultaneous measurement of near-bottom currents and sediment trans-
port or sediment bedforms, although difficult, has been conducted by some

workers. McClennen (1973) reported that sediments off the New Jersey coast



STATION NO.

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50

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150

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400

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78-12
: a

Figure 11.

Vertical section of temperature (°C) showing late fall
conditions in outer shelf and slope waters. From Cook
and Hughes, 1980.

48



DISPERSON OF POLLUTANTS (Cont. )

Reference Area Description

O'Connor & Mancini New York Bight steady-state evaluation of
(1979) mechanisms influencing dis-

solved oxygen levels and of
engineering solutions for
existing water quality problems

O'Connor, Mancini New York Bight time-variable version of

& Guerriero (1981) O'Connor & Mancini (1979)

Brown & Kester (1981) DWD-106 stratified microcosm

Morel & Farley marine dumpsites second order rate model for

(1981) particle removal by coagulation

Atwood, et al (1979) New York Bight determination of assimilative
capacity

Csanady, et al (1979) DWD-106 determination of assimilative
capacity

97


UPWELLING

The process of upwelling, whether wind-driven (divergent transport of
surface water by wind action) or dynamic (interaction of currents and
bathymetry) involves divergent horizontal transport of surface water which
is replaced by deeper water with different properties. The area of upwelled
water usually is bounded by a front, where upwelled water converges on the
indigenous surface water. Thus, upwelling, if occurring in polluted waters,
also would transport pollutants horizontally, and the fronts created by
the upwelling process could concentrate floating pollutants. Upwelling of
anoxic bottom water, such as that which occurred along some New Jersey
beaches in the summer of 1976, can impact on marine organisms in the near-
shore area and human utilization of these waters.

Frequently, upwelling leads to increased phytoplankton productivity,
because of the higher concentrations of dissolved nutrients carried by the
upwelled water. If this occurs in a nearshore area that already carries
high nutrient concentrations from runoff and discharges of waste materials
from urban centers, it may drive the coastal ecosystem closer to eutrophica-
tion. Some of the nearshore band of high phytoplankton productivity found
along the northern New Jersey coast involves the interaction of these two

enrichment processes.

Northern Georges Bank
Bigelow (1927) first implied that upwelling was active along the
northern edge of Georges Bank and discussed the resultant "consumption"

of slope water during the spring. Since then various measurements have

22



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35°
32 '
33° VUZE
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34°. ;
/
7
4
ot, -.
33 iy
|
75°

Effluent plume from Chesapeake Bay as revealed by surface
salinity (parts per thousand) during 28 July-3 August 1972
after the passage of Hurricane Agnes in June. From
Boicourt, 1973.

Figure 5.

18

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101


Semtner, A, J. and Y. Mintz. 1977.
of the Gulf Stream and mid-ocean eddies.
Oceanogr. 7:208-230.

Numerical simulation
J. Phys.

The circulation of the western North Atlantic is simu~
lated with a primitive equation model that has 5 levels and
a horizontal grid size of 37 km. The idealized model do-
main is a rectangular basin, 3000 km long, 2000 km wide and
4 km deep, which is oriented so that the long axis of the
basin is parallel to the east coast of the United States.
The nearshore side of the basin has a simple continental
shelf and slope, whereas the other sides are bounded by
vertical walls. The model ocean is driven by a 2% gyre
pattern of steady zonal wind stress and by a Newtonian-
type surface heating. After initialization from a 15-
year spin-up with a coarser grid, two experiments are
carried out each of several years duration: the first
uses a Laplacian formulation for the subgrid-scale lateral
diffusions of heat and momentum, the second uses a highly
scale-selective biharmonic formulation ofr these diffu-
sions. Bottom friction is present in each case.

In both experiments, a western boundary current
forms which separates from the coast and continues east-
ward as an intense free jet, with surface velocites >1 m
s-*for almost 1000 km downstream. In the experiment
with biharmonic closure, this simulated Gulf Stream
develops large-amplitude transient meanders, some of
which become cold-core cyclonic rings and warm-core
anticyclonic rings that drift westward. In both exper-
ments, transient mesoscale eddies also form in the
broad westward-moving North Equatorial Current, where
the simulated thermocline in the model ocean slopes
downward toward the north, The remaining regions of
the model ocean also contain transient mesoscale eddies,
but they are of weaker intensity.

The dominant process of eddy kinetic energy pro-
duction, in both experiments, is a baroclinic-barotropic
instability which is concentrated in the part of the
Gulf Stream that is over the continental slope. But
where the Gulf Stream lies over the abyssal plains,
there is large reconversion of eddy kinetic energy
into the kinetic energy of the time-averaged flow.

Eddy kinetic energy is also produced by baroclinic
instability in the North Equatorial Current, but at a
much smaller rate. In the biharmonic experiment, the
eddies transfer considerable kinetic energy downward,
and bottom friction is the dominant process of eddy
kinetic energy dissipation.

An analysis of the heat transport, in the bi-
harmonic experiment, shows that the horizontal trans-
port of heat by eddies is much larger than the sub-
grid-scale horizontal heat diffusion. In the Gulf,
Stream region, the eddy heat transport is comparable
to,the effect of a lateral diffusion coefficient of

10” cm? s-

158

Sharp, J. H. In press. In situ phosphate
regeneration in Middle Atlantic coastal
waters. In: Ecological Stress and the
New York Bight: Science and Management,
G. F. Mayer (ed.). Estuarine Research
Federation.

Concern exists over man's disposal of
bioactive nutrients into the marine environ-
ment. These nutrients can stimulate microbial
plant production that, if not consumed in
marine food chains, can cause serious oxygen
demands. To understand the impact of man's
input of nutrients it is necessary first to
gain a better understanding of natural
nutrient cycles. This paper attempts to
quantify natural phosphate regeneration in
bottom waters of three regions in Middle
Atlantic coastal waters and to evaluate the
contributions that in situ nutrient regenera-
tion could make toward supporting microbial
plant production. It is striking that the
apex of the New York Bight, with hich
production, receives a much smaller pro-
portion of its phosphate supply from in situ
regeneration than adjacent New Jersey an
Long Island coastal waters. The approach
taken here is the first of its kind for
quantifying and comparing coastal nutrient
regeneration.

Sharp, J. H. and T. M. Church. 1981.
Biochemical modeling in coastal waters
of the Middle Atlantic States. Limnol.
Oceanogr. 26(5):843-854.

Biochemical dynamics in coastal waters
off the U.S. Middle Atlantic States are ex-
amined by applying the Redfield model of
nutrient regeneration and apparent oxygen
utilization, The modeling takes advantage
of the comparatively uniform spatial con-
ditions of the seasonally stratified cen-
tral shelf region and follows temporal
changes in the isolated bottom waters on
an integrated mesoscale. A seasonally
averaged rate of bottom water nutrient
regeneration of 0.0044 umol P-liter”2d-*
results and this permits estimation of a
nitrogen flux across the thermocline
equivalent to 0.02 umol N-1iter ?-d-?,
This nitrogen flux and an extrapolated
surface water nutrient regeneration

could supply at least one-third and may-
be close to two-thirds of the total ni-
trogen requirement for the phytoplankton
productivity during summer in these
coastal waters.

Shaw, P. T. 1987. On the dynamics of bottom
water movement in the Middle Atlantic Bight.
Paper presented at Middle Atlantic Bight
Physical Oceanoaraphy Workshop, Univ. of
Rhode Island, 21-22 October, 1987.


Sutcliffe, W. H., dr., R. H. Loucks and K. F.
Drinkwater. 1976. Coastal circulation and
physical oceanocraphy of the Scotian Shelf
and Gulf of Maine. J. Fish. Res. Bd. Canada,
33(1):98-115.

Swanson, R. L. 1976. Evaluation of proposed
sewage sludge dumpsite areas in the New York
Bight. NOAA Tech. Memo. ERL MESA-11. U.S.
Dept. Commerce, NOAA, Wash., DC, 212 pp.

Swanson, R. L. 1976. Tides.
Atlas Monograph No. 4.
Sea Grant Inst.

MESA,
Albany,

N.Y. Bight
NY, New York

* Times of high and low tides and tidal ranaes
are mapped. Seasonal variations and accuracy of
predictions from tide tables are shown. Variation
‘in the range of tide and time of high water along
the east coast can be correlated with width of the
shelf. Long Island Sound, a major embayment,
modifies the co-tide and co-range lines in the
northeast portion of the bight.

Swanson, R. L. 1981. The pros and cons of ocean
dumping sewage sludge at the 12-mile, 65-mile
and 106-mile sites. Presentation to Third
International Ocean Disposal Symposium,
Woods Hole, MA 12-16 October 1981.

Swanson, R. L. and C. J. Sindermann (eds.) 1979.
Oxygen depletion and associated benthic mortalities
‘in New York Bight, 1976. NOAA Prof. Pap. 11.
U.S. Dept. Commerce, Rockville, Maryland 345 pp.

Swanson, R. L., C. J. Sindermann, and G. Han,
1979. Oxygen depletion and the future:
An evaluation. Chap. 16 In: Oxygen depletion
and associated benthic mortalities in New
York Bight, 1976. R. L. Swanson and C. J.
Sindermann (Eds.}. NOAA Prof. Pap. No. 11.
U.S. Dept. Commerce, Rockville, MD.

Swanson, R. L., H. M. Stanford, J. S. O'Connor, S.
Chanesman, C. A. Parker, P. A. Eisen and G. F.

Mayer. 1978, dune 1976 pollution of Long Island
ocean beaches, J. Envi. Eng, Div. ASCE, 104(EE6):
1067-1085.

In June 1976, Long Istand's ocean beaches were
inundated with floating wastes including sewage-related
material, trash, and garbage. The material exited
the Hudson-Raritan, estuary as a result of high spring
runoff and intensive May rains. Once introduced into
New York Bight waters, it was transported to the
beaches by persistent southerly winds. The major
sources of the floatable wastes were urban runoff
and sewage treatment plant bypassing feeding through
the combined sewer system. Assessment was accom-
plished by comparing waste materials found on the
beaches with the types and volumes of materials
associated with suspected sources. Continual washups
of floatable material can be expected, particularly
during summer months, until better source and screening
controls are implemented.

161

Swift, D. J. P. 1975. Response of the shelf floor
to geostrophic storm currents of the Middle
Atlantic Bight of North America. 1975. Proc.
of Sth International Congress of Sedimentology,
Nice. 1975. Theme 6, pp. 193-198,

Swift, D. J. P., 0. B. Duane, and I. F. McKinney.
1971. Topographic Rossby waves at a site north
of the Gulf Stream, Deep-Sea Res. 18:1-19.

* Current velocity was sampled every 15 minutes
with minimized aliasing for over 3 years at site-D
(39-40 N, 70 W) at depths of 100 m, 500 m, 1000 m,
and 2000'm, Following averaged subsampl ing over
114 hours (9.5 semi-diurnal tide cycles, 6 inertial
periods), a variant of complex demodulation was
used to obtain spectra, cospectra and quadrature
spectura for the 4 depth series. The correlations
obtained relative to the geometric arrangement of
the slope and Gulf Stream forcing function are
interpreted as topographic Rossby waves.

Swift, D. J. P., G. L. Freeland, P. £. Gadd, G. Han,
J. W. Lavelle, and W. L. Stubblefield. 1976.
Norphologic evolution and coastal sand transport,
New York - New Jersey Shelf. In: Special Sym-
posia Vol. 2, Middle Atlantic Continental Shelf
and the New York Bight. (M. Grant Gross, Ed.)
Am. Soc. Limol. Oceanogr. p. 69-89.

The surface of the New York-New Jersey shelf
has been extensively modified by landward passage
sedimentary environments during the postglacial
rise of sea level. The retreat of estuary mouths
across the shelf surface has resulted in shelf val-
ley complexes. Constituent elements include shelf
valleys largely molded by estuary mouth scour,
shoal retreat massifs left by the retreat of es-
tuary mouth shoals, and midshelf or shel f-edge
deltas.

The erosional retreat of the straight coast be-
tween estuary mouths has left a discontinuous sheet
of clean sand 0-10 m thick. During the retreat oro-
cess, a sequence of oblique-trending, shoreface-
connected sand ridges formed at the foot of the
shoreface. As a consequence, the surficial sand
sheet of the shelf floor bears a ridge and swale
topography of sand ridges up to 10 m high and 2-4
m apart.

The mechanics of sedimentation in these two
nearshore environments (estuary mouth and inter-
estuarine coast) are now being investigated for
purposes of environmental management as well as
for futher understanding of shelf history. In
late fall and winter 1974, current meters were de-
ployed on the Long Island coast and a radioisotope
tracer dispersal pattern was traced over an 11-week
period. Eastward or westward pulses of water were
generated during this period of successive weather
systems. Flows in excess of the computed thres-
hold velocity of substrate materials were sustained
for hours or days and were separated by days and
weeks of subthreshold velocities, and the sand
tracer pattern expanded accordingly. A single in-
tense westward flow transported more sand than all
the other events combined. The storm was anomalous
with respect to the short term observation period,
but it may in fact have been representative of the
type of peak flow event that shapes the inner shelf
surface.

Systematic observations of sedimentation in
New York Harbor mouth have not yet been initiated.
However, reconnaissance data reveal a complex pat-
pern of ebb- and flood-dominanted zones that
control the pattern of sand storage.


Webster, F. 1969,
ocean currents.

Vertical profiles of horizontal
Deep Sea Res. 16:85-98,

* This report is an analysis of data collected
by Richardson-type current meters suspended from
moored buoys at Site D (39 deg. 20 min N.,

070 deg. W) in the western North Atlantic. Thirty
records representing 40 months of current profile
data at approximated depths of 10, 100, 500, 1000
and 2000.m were taken. Conclusions from these
polar derived vertical profiles are as follows:
the mean velocity at Site D is to the west, with
amplitude decreasing with depth; the kinetic
energy of the time-dependent currents is propor-
tional to the Brunt-Vaisala frequency; the mean
speed at Site D is principally due to rectified
time-dependent processes; time-dependent currents
below the depth of the continental shelf show

the shelf's restrictive influence; and the eddy
transport of momentum changes sign at the depth
of the shelf.

Mid-level intrusions at the
J. Geophys. Res.

Welch, C. S. 1981.
continental shelf edge.
85(C11):11,073-11,019.

Observations across the continental shelf
offshore from New Jersey in late summer 1976 show
an intrusion of saline water at the mid-level of
the water column across the shelf edae front, which
appears in density only as an offshore thickening
of the pycnocline. This internal density field
produces horizonta? pressure gradient forces
within the pycnocline in the onshore direction.
These forces, in the linearized equations of
motion with a constant eddy viscosity, drive a
circulation which resembles a double Eknan spiral
for internal pressure vertical distributions
which are thin with respect to the Ekman depth.
For thick pressure distributions, the circulation
is geostrophic. The resulting flow pattern
has no net cross-shelf transport. For the con-
tinental shelf edce in the example, a northward
geostrophic mid-level jet is predicted by the
theory. Ekman depth, and thus the vertical co-
efficient of eddy viscosity, can be determined
from hydroaraohic data describing an intrusion.

Whitcomb, V. L. 1970. Oceanography of the
Mid-Atlantic Bight in support of ICNAF,
September-December 1967. U.S. Coast Guard
Oceanogr. Rep. No. 35, 157 pp.

Whitledge, T. £., A. Mattee, R. Waldhauer, J. J.
Walsh, L. J. Castiglione, L. A. Codispoti,
S. D. Howe, C. D. Wirich, and R. E. Tucker.
1976. Transient forcings of the lower trophic
levels during the spring bloom within the New
York Bight. Am. Soc. Limnol. Oceanogr. ,
Spec. Symp 2:273-274.

* An objective analysis of a time series study

of the spring bloom in the New York Bight across the
continental shelf, south of Long Island, from

March 26 to April 9, 1975 is presented. Neasure-
ments of temperature, salinity, irradiance, nutrients,
chlorophyll, phytoplankton, particles, particulate
nitrogen and carbon, zooplankton, primary production,
respiration, and nitrate uptake over the two week
period suggests maximum productivity and minimum
grazing stress at midshelf.

165

Whitlock, C. H. and T. A. Talay. 1974, The
influence of surface waves on water circula-
tion in a Mid-Atlantic continental shelf
region, NASA Tech. Note NASA TN D-7771.
Langley Research Center, Hampton, VA 23665.
45 p.

The importance of wave-induced currents in
different weather conditions and water depths
(18.3 m and 36.6 m) is assessed in a mid-Atlantic
continental shelf reaion. A review of general
Circulation conditions is conducted. Factors
which perturb the general circulation are
examined using analytic techniques and limited
experimental data. Actual wind and wave statis-
tics for the reaion are examined. Relative
magnitudes of the various currents are compared
ona frequency of annual occurrence basis.
Results indicate that wave-induced currents
are often the same order of magnitude as other
currents in the region and become more important
at higher wind and wave conditions. Wind-wave
and ocean-swel) characteristics are among those
parameters which must be monitored for the
analytical computation of continental-shelf
circulation.

Wigley, R. L. and F.C. Stinton. 1973.
Distribution of macroscopic remains of
recent animals from marine sediments off
Massachusetts. Fish. Bull, 71(1):1-40.

Williams, R. G. 1969.
Block Island Sound.
Lab. Rep. No. 966.

Physical oceanography of
Nav. Underwater Sound

Williams, R. G. and F. A. Godshall. 1977.
Summarization and interpretation of
historical physical oceanographic and
meteorological information for the Mid-
Atlantic region. U.S. Dept. Commerce,
NOAA, Wash., DC. Final report to the Bur.
of Land Management, U.S. Dept. of the
Interior, Interagency Agreement AA55O-IA6-
12. 295 pp.

Wilson, Robert E. 1979. A model for the estimation
of the concentrations and spatial extent of
suspended sediment plumes. Estuarine & Coastal
Mar. Sci. 9:65-68.

A simple model is presented for the spatial
structure of suspended sediment plumes produced by
over-board pipeline disposal of dredge spoil in
shallow waters. The model ts based on a solution
to the advection-diffusion equation for a continuous
vertical line source. It provides information on
the variation of both centerline concentration and
the second moment of the lateral distribution with
distance from the source, The structure of the plume
is described by only two parameters: one proportional
to the settling velocity of the suspended material
and the other equal to the ratio of a diffusion
velocity to the advective velocity of the ambient
flow. The model has been applied to represent the
structure of observed suspended sediment plumes at
three separate shallow water sites.


Injections of slope water and modified Gulf Stream water onto the
shelf by warm core rings has been frequently observed in vertical tem-
perature sections from shipboard data. Pronounced examples have been
reported for southwestern Georges Bank (EG&G, 1978) and southern New
England (Crist and Chamberlin, 1979) (Fig. 7). Because injection onto
the shelf is predominantly subsurface, satellite data provide only circum-
stantial evidence by showing where this process may be taking place.

Information is scarce on the influence of warm core rings on shelf
circulation except for what can be inferred ordinarily regarding entrain-
ment immediately adjacent to rings. One fortuitous data set showing this
sort of influence was from drogued buoys on SN Georges Bank in November
1977, which showed reversal of "the expected downcoast (southwestward)
mean flow" apparently caused by a warm core ring (EG&G , 1978). Again as
in the case of injections, the satellite data only indicate where such a
circulation influence may be taking place.

Pronounced differences in the interaction of warm core rings and Gulf
Stream meanders with shelf water are apparent between Georges Bank and
the Middle Atlantic continental shelf. These differences relate pri-
marily to the propagation characteristics of the rings and meanders.
Although a number of the analyses necessary to make quantitative com-
parison have not been completed, the differences can be described quali-
tively:

a. Those which approach Georges Bank do so when younger, larger,

and stronger in rotary flow than when they later enter the
waters off the Middle Atlantic Shelf.

b. About 35% more rings occur in the vicinity of Georges Bank.

30



Bishop, J. M. and J. E. Overland. 1977.
drift on the Middle Atlantic Shelf.
Res. 24:161-169.

Seasonal
Deep-Sea

A relationship among non-tidal surface currents,
seasonal density distributions, and mean wind stress
is developed from the thermal wind relation and Ekman
dynamics. The result can be interpreted as a simple
shallow water equivalent of the dynamic method. This
approach indicates that summer currents on the Middle

Atlanti¢ Shelf set southwestward on the order of 5 to
15 cms~! and are maintained by the density distribu-
tion. In winter, winds predominate over the weak

contribution from the density field. Winter mean
wind stress implies southward flow on the order
of 15 cms“!, Drift estimates are consistent with
atlas values.

Boicourt, W. C. 1973, The circulation of water on
the Continental Shelf from Chesapeake Bay
to Cape Hatteras. Ph.D. Thsis. The Johns
Hopkins Univ., Baltimore, MD. 183 pp-

Boicourt, W. C. 1981. Circulation in the Chesapeake
Bay entrance region: Estuary shelf interaction.
p. 61-78. In: Chesapeake Bay Plume Study ~
Superflux 1980. NASA Conference Publ. 2188.
J. W. Campbell and J. P. Thomas (eds.),
516 pp. Scientific & Technical Information
Branch, National Aeronautics & Space Admn.
Wash. , DC.

‘Summary

Current meters and temperature-salinity
recorders confirm that the upper layers of the
continental shelf waters off Chesapeake Bay can
be banded in summer, such that the coastal boundary
layer (consisting of the Bay outflow) and the outer
shelf flow southward while the inner shelf flows
to the north, driven by the prevailing southerly
winds. These measurements show that the estuary
itself may also be banded in its Tower reaches
such that the inflow is confined primarily to
the deep channel, while the upper layer outflow
is split into two flow maxima on either side of
this channel.

111

Boicourt, W. C. and P. W. Hacker. 1976. Circula-
tion on the Atlantic continental shelf of the
United States, Cape May to Cape Hatteras.
Mem. Soc. Royale des Sci. de Liege, 6(10):
187-200.

Observations from two sets of experiments on
the northeast continental shelf of the United
States reveal details of the response of the shelf
waters to strong wind forcing. Measurements of
currents within a cross-shelf section show that
northerly winds can move water on the outer shelf,
one shelf-width to the south within a three-day
interval. These observed high-velocity motions
are in contrast with the long-term mean flow to
the south of order 5 - 10 cms-!. For both the
winter (unstratified) and the summer (stratified)
seasons, lateral shear is evident in the storm-
driven iongshore flows, with velocities increasing
in the offshore direction. Cross-shelf motions
during these wind events are qualitatively con-
sistent with Ekman theory. Southerly wind events
can drive offshore motion in the upper Ekman layer,
requiring subsurface return flow. This return
flow, which consists of high salinity Slope Water,
appears to occur in a bottom Ekman layer during
the unstratified season. Under stratified con-
ditions, the return flow occurs at mid-depth,
above the cold water band at the shelf break.

The second set of experiments, designed to
measure the longshore variability of the response
to strong wind events, were made with two current
meter moorings separated along the 35 m isobath.
The results show that at separations of 130 km and
235 km, the longshore component of velocity is well
correlated during both high and low flow conditions
The cross-shelf component is poorly correlated,
except during the highest flows. The shelf
appears to respond as a unit to strong wind
events over longshore scales of at least 235 km.

Boicourt, W. C., D-P Wang, and W-S Chuang. 1979.
Low-frequency current variability on the
southern Mid-Atlantic Bight. J. Phys.
Oceanogr. 9:1144-1154, November 1979.

+ "Results of this study indicate that circula-
tion in the southern Bight is affected by local
alongshore wind forcing as well as the disturbances
propagating from the north. Stratification is
essential in determining the cross-shelf circula-
tion. Persistence of alongshore wind seems to be
another important factor. Therefore, three-dimen-
sionally, time dependency and density stratification
are all essential in modeling the circulation of
the Mid-Atlantic Bight.”

This paper is an objective analysis of low-
frequency current variability on the continental
shelf taken during a 4 month period in 1975
(March to June). A current meter mooring
iTocated 84 km off the coast of the Chesapeake Bay
collected data at depths of 10, 20, and 30 m.



Harrison et. al 1967 continued. Hart, J. E, 1975p, Baroclinic instability over a slope
part II: Finite-amplitude theory. J. Phys. 0c 5:
Part III.- Vectors of surface and bottom 634-641.

drift inferred fron drifter recovery data are
correlated with winds and runoff by means of
multiple linear regression procedure. Pre-
ictands are U and V drift components for each
straight line drifter trajectory. Predictors
are u and v wind components for each of three
lightships, averaged over the period a drifter
was adrift, and 2] stream-discharge values

Baroclinic instability of a circular current is
modified by the presence of a unidirectional bottom slope.
An analytical theory is developed for the slightly unstable
flow regime over a weak slope. The presence of the slope
creates azimuthal sidebands ntl to the basic azimuthal
wavenunber n, of the instabi The interaction of the
sidebands with the slope causes a decrease in the stability

lagged in time to provide estimates of runoff
at each of three points along the coast. (The
sense of the U or_u components is from east
to west and V or V components from north to
south. )
A partial correlation model between wind
or runoff and surface and bottom drift com-
ponents is constructed in a series of sketches
based_upon the stronger correlations between
U or V and the strongest predictor. The model
reflects the importance of "permanent" flow
on certain correlations and reveals weaknesses
inherent in the two-variable correlations. The
importance of developing multivariate equations
for predicting surface and bottom drift is apparent
after a detailed examination of the model,
Predictor equations containing four predictors
are developed by subjecting 27 possible predictors to
a computerized screening procedure. The resultant
equations are evaluated by the R2 criterion and by
testing acceptable equations on an independent set
of data that is synchronous with the dependent data.
The root mean square error (RMSE) resulting from
the application of a given equation to independent
data is compared to the standard deviation of the
observations (dependent data) from which the equa-
tion was derived. If the RMSE is less than one-fifth
the standard deviation, and if the first two pre-
dictors seem physically significant, the equation
is deemed acceptable for final evaluation. Some
equations do not make reasonable predictions on the
dependent data during periods in which drifter
recovery data are sparse. These equations are
considered reliable for interpolation of the drift
only during those periods when most of the observa-
tions on which they are based were gathered.

Hart, J. E. 19754. Baroclinic instability
over a slope. Part I: Linear theory.
J. Phys. Oceanogr. 5:625-633.

We consider the instability properties
of a circular current in the upper layer of a
two-layer quasi-geostrophic ocean over a uni-
directional slope. This particular flow
topography geometry is intended as a crude
model of geophysical gyres where the variation
of the Coriolis force is negligible, Such
currents occur in the Arctic and in Gulf Stream
rings. The slope destabilizes the flow; the
critical Froude number is lowered as the slope
increases. Baroclinic instabilities tend to
generate time-independent or mean currents in
the upper and lower layers which, because of the
slope, are markedly asymmetric across the gyre.

132

of the flow compared with that in the case with a flat
bottom.
baroclinic wave produces a time-independent asymmetric
current. In addition, the basic wave self-interaction
produces a time-independent current which flows up the
slope and generates asymmetric vorticity. This latter

effect is predominant when the Rossby radius of deformation

is much smaller than the radius of the basic current.

Hatcher, P. G. and P. A. McGillivary. 1979.
Sewage contamination in the New York
Bight. Coprostanol as an indicator.
Env'l Sci. & Tech. 1225-1229,

Hayes, R. M. 1975. Oceanographic observations Nova
Scotia to Cape Hatteras, North Carolina
October-November 1969 and May-June 1970.
Oceanographic Report No. CG 373-66. U.S.

Sgast Guard Oceanographic Unit, Washington, DC
3 pp.

A volumetric statistical (T-S) analysis of water
masses is presented for two Coast Guard oceanographic
cruises in support of the International Commission
for the Northwest Atlantic Fisheries, Nova Scotia to
Cape Hatteras, North Carolina from 25 October to
22 November 1969 and 19 May to 9 dune 1970. The fall
cruise data exhibited a 54% greater volume of Gulf
Stream water in the survey area than the spring cruise,
a result of a Gulf Stream meander which brought large
volumes of tropical water into the slope region,
Effectively the Gulf Stream meanders resulted in an
exchange of water masses bringing oceanic water into
the coastal zone and vice versa. Seasonal changes
in the geostrophic conditions shoreward of the Gulf
Stream may influence the extent of intrusion of that
water mass into the continental shelf region.

Hazelworth, J. B. and S. R. Cummings. 1979. Chapter
5. Physical conditions compared with previous
years. In: Oxygen Depletion and Associated
Benthic Mortalities in New York Bight, 1976.
Swanson, R.L. and C. J. Sindermann (Eds.).
NOAA Prof. Paper 11, pp. 125-135.

* This paper compares density (sigma t), tempera-
ture, and salinity data obtained in 1976 with the
same data obtained in previous years.

Heezon, B. C., C, 0. Hollister and W. R. Ruddiman.
1966. Shaping of the continental rise by
deep geostrophic contour currents.

Science 152:502-508.

The interaction of the sidebands with the primary


(seaward edge of cold pool) average about 1 meter-day-! (Garrett and Horne,
1978). While the cold pool is easily identifiable along its lateral
boundaries as a thermal feature and less so as a salinity feature, it is
totally unidentifiable laterally as a density feature. Therefore, mixing
could occur with surrounding water masses along density surfaces laterally

(cross shelf) far easier than with overlying water.

Hypoxia

During the summer of 1976 oxygen-deficient (hypoxic) conditions
developed in sub-thermocline waters, including the cold pool, on the con-
tinental shelf off New Jersey, causing mass mortalities of benthic organisms
and displacements of finfish populations. These conditions persisted
from July through September and extended over an area of about 8600 km2.
Because of the large magnitude of this catastrophe, considerable attention
was directed toward determining the circumstances that caused the severe
depletion of oxygen. A summary report was prepared of the findings
(Swanson and Sindermann, 1979) in which it was concluded that (1) a
combination of natural, but anomalous, events generated the Tow oxygen
condition, (2) man's activities had little or no discernible effect, and
(3) future recurrences should be expected, particularly since low oxygen-
related marine mortalities had also developed in the same area in 1968,
1971 and 1974, although they were of lesser extent than that which
occurred in 1976.

Factors which were identified as contributing to the hypoxia of
1976 were (1) early initiation of stratification of the waters due to

early warming of the surface waters and lowering of surface salinities

54



Beardsley, R. C. and W. C. Boicourt. 1981. Gn
estuarine and continental shelf circulation
in the Middle Atlantic Bight. Chap. 7
(p. 198-235) In: Evolution of Physical
Oceanography Scientific Surveys in honor of
Henry Stonmel. The MIT Press, Cambridge, MA
623 pp.

7.3.4 Summary and Some Remaining Problems

We have attempted here to describe the shelf
response to wind forcing on three time scales.
Synoptic-scale atmospheric disturbances and in
particular winter cyclones can drive strong transient
current fields that tend to move along the shelf in
phase with the forcing. The cross-shelf momentum
balance is approximately geostrophic and both the
current and subsurface pressure fluctuations are
generally coherent over much of the Middle Atlantic
Bight, reflecting the relatively small size of this
shelf region with respect to the atmospheric forcing.
The synoptic-scale shelf response appears to be con-
sistent with continental shelf-wave theory. The
direct effect of wind forcing is also evident in the
monthly-mean shelf circulation, although the observed
currents have a complex spatial structure and other
processes like runoff and offshelf forcing contribute
to the variability on this time scale. The mean flow
over the Middle Atlantic Bight is primarily driven not
by local runoff and wind stress but by the large-scale
wind stress and heat-flux patterns over the western
North Atlantic. Thus the observed currents can be
decomposed into a mean component driven by a steady
offshelf forcing and a fluctuating component driven by
the regional wind stress field acting over the shelf.

This review has focused on the wind-driven circu-
lation components in the Middle Atlantic Bight. The
actual influence of density stratification on the dif-
ferent components of the general circulation is stil]
not clear, and only a crude estimate of the flushing
rate of the shelf is available. The processes control-
Ving the local position and movement of the shelf-slope
water front are poorly known. As noted by Fofonoff
(chapter 4, this volume), satellite infrared mapping
of the sea surface temperature has greatly added to
our perception of the spatial variability and complex-
ity of the near-surface current and thermal fields.

Beardsley, R. C. and 8. Butman. 1974. Circulatior
of the New England continental shelf: Response
to strong winter storms. Geophys. Res. Letters
14:181-184.

* A brief data-modelling paper in which the
authors engage in a discussion of "current
measurements along with coastal sea level observa~
tions and suggest a simple model for the wind-
driven response of the shelf circulation to strong
winter storms".

The study "focuses on the winter circulation
of the continental shelf waters on the section of
the Mid-Atlantic Bight from Nantucket Shoals to
Sandy Hook, New Jersey" in March of 1973.

During the period of data collection three
winter storms passed through the area.

“The observations show that large westward
mass transports along the shelf were produced
by strong easterly winds, while westerly winds
produced little elongshore flow. Significant
cross-shelf and alongshelf surface pressure
gradients occur during the storms."

108

Beardstey, R. C. and C. N. Flagg. 1976. The water
structure, mean currents and shelf water/slope
water front on the New England continental
shelf. Mem. Soc. Royale des Sci. “de Liege.
6(10): 209-225.

Beardsley, R. C. and D. B. Haidvogel. 1981
Model studies of the wind-driven transient
circulation in the Middle Atlantic Bight.
Part 1: Adiabatic boundary conditions.
Jour. Phys. Oceanog. 11(3):355-375.

A numerical model of the wind-driven transient
ocean circulation in the Middle Atlantic Bight is
described. The model incorporates realistic topog-
raphy and covers the continental shelf between the
coast and the 200 m isobath from Cape Hatteras to
the southern tip of Nova Scotia. The traditional
shallow-water dynamics are used, i.e., the vertically
integrated and linearized equations for the flow of
a homogeneous fluid driven by atmospheric pressure
and wind stress fluctuations and damped by a quad-
ratic bottom stress. The equations are integrated
in time using a simple modification of Plataman's
(1972) Finite-difference scheme, with a 12.7 kn
grid spacing. At the coast, normal flow is re-
quired to vanish; at non-coastal boundaries, the
equivalent surface elevation is held fixed.

Several classes of initial value experiments
are used to study the free and forced modes of
this model, and the damped flow driven by a
spatially uniform and stationary wind stress and
by an idealized traveling synoptic-scale wind-
stress pattern, The numerical experiments indicate
that several time scales are important in the
regional adjustment process. These are an inertial
time scale dependent on the regional long-wave
propagation speed, a local frictional time scale
dependent on the strength of the depth-averaged
velocity field, and a longer time scale which
reflects the adjustment process within the entire
model. The transient response within the Middle
Atlantic Bight proper from Cape Cod to Cape
Hatteras to an alongshore wind stress is clearly
dominated by friction and rotation. The effective
spinup time scale for a 2 dyn cmr2 wind stress is
about 10 h at New York. This is sufficiently
short in comparison to the 4-10 day time scales
characterizing atmospheric transients that the
storm-driven currents should be quasi-steady.
Within the deeper Gulf of Maine basin, the ef-
fective spinup time scale is much longer and the
normal modes of the basin excited by the wind forcing
are only weakly damped in tine.

A comparison of model and observational data
on current and sea level variability indicates
that the model response is more realistic within
the Middle Atlantic Bight section of the model
domain, Differences within the Gulf of Maine are
due primarily to the specific boundary condition
imposed on the upcoast (Scotian shelf) boundary.



Acid Dump Site

Dumping of non-toxic chemical wastes from National Lead Corporation
at the so-called "acid site" located 28 km east of the northern New
Jersey coast near 40°20'N, 73°40'W (Fig. 14) has occurred since 1948.
Some of the earliest studies of dispersion and mixing of dumped wastes
were conducted there (Redfield and Walford, 1951; Ketchum and Ford, 1952).
These investigators found that dilution of the waste due to the dumping
barge's wake turbulence was from 250 to 500:1 immediately behind the
barge. After the barge's passing, the polluted wake continues mixing
with the surrounding waters, and initial wideriing of the wake plume
continues for about 30 min., but its vertical deepening reaches the maxi-
mum extent almost immediately. Vertical measurements showed identifiable
waste near bottom at 24 m, 410 m astern of the dumping barge during
January 1950 (Redfield and Walford, 1951), but during April 1948 measure-
ments showed a vertical penetration of only about 10-12 m. Increased thermal
stratification (in April) leading to a decrease in density of the surface
waters is believed responsible for the noted differences in vertical pene-
tration of the waste. Discrete measurements of the jron concentrations
and some simplifying assumptions allowed Ketchum and Ford (1952) to estimate
mixing coefficients (effective diffusivities) for the acid waste plumes.
They assumed that each unit length of the barge wake contained the same
amount of dumped waste and that the concentration distribution across the
wake's axis was normal. Thus, from: Y = N/2(ken)~3(t) 72, where Y = iron
concentration, t = time, N = barge discharge rate, ke = effective diffusivity,
they computed k, from data collected in the field. They found that effective

diffusivities varied from 2 x 103 cm@-sec-! in April and July to nearly

72



Massachusetts Bay

Analyses conducted by Kangas and Hufford (1974) of temperature profiles
collected by bathythermographs on the Boston Lightship (32 m water depth)
during 1964-71 revealed that upwelling commonly occurs there during summer.
Prevailing winds from the southeast to west, common during the summer,
provide the offshore transport of surface waters followed by upwelling of

deeper, cooler water.

Middle Atlantic Bight

During the periods of prevailing southwesterly winds, mostly in the
summer months, upwelling should occur along the New Jersey-Virginia coast.
An analysis of surf temperatures wind velocities, and nearshore tempera-
ture sections off Monmouth Beach, N.J. by Hicks and Miller (1980) demonstra-
ted the linkage between southerly winds and shoreward motion of the cold
bottom water, which in many cases came into the surf zone.

In the analysis of data and events involved in the development of
anoxic conditions in the bottom water and resulting high benthic mortalities
off New Jersey in the summer of 1976, some evidence of upwelling was un-
covered. Mayer, Hansen and Minton (1979) found indications of upwelling
off northern New Jersey in 5 of 13 months and off western Long Island in
8 of 12 months of current meter data; in each case it was persistent enough
to register in monthly mean current vectors. Analysis of wind field ob-~
servations for the inner New York Bight for February-June 1976 by Diaz
(1979) produced monthly mean offshore transports (computed Ekman) in the
surface layer each month, but strongest off New Jersey in February. Steimle

and Sindermann (1978) reported observations of dead and dying fish and

24


Reference

Beardsley & Hart
(1978)

Harrison, et al.
(1967)
Kao (1981)

Garvine (1979a, b,
1980)

ESTUARINE EFFLUENT PLUMES

Area
Hudson & Chesapeake Bay
estuaries
Chesapeake Bay mouth

Chesapeake Bay plume

Connecticut River plume

90

Description

2-D flow of estuary onto
shelf, driven by runoff

multiple linear correlation
of drifters with winds and
runoff

2-D model driven by fresh
water

2-D model, integral technique



2
&
BS

Sp

150

100M
40M

CAPE HATTERAS

The North American coast and waters of the
shelf and slope from Nova Scotia to Cape
ina.

Hatteras, North Carol

Figure 2.


7 x 103 cm@-sec"] in January and proposed that the higher diffusivity
measured in January was due to the less stable water column present at
that time relative to the other two experiménts.

Gordon and Gerard (1973) more recently summarized their findings
regarding the spread of contaminants in shelf water. Using a combination
of dye tracer studies and free drifters in the vicinity of Ambrose Light
Tower together with aerial photographs from the nearby acid site, they
found large vertical and horizontal shear zones occurring in the upper
portions of the water column related to wind. The largest vertical shear
values, 12 cm-sec-1, were observed across the pycnocline between the
surface mixed layer and underlying water during periods of highly stable
(stratified) conditions, and the least vertical shear was observed during
neutrally stable (unstratified) conditions. Thus, waste plumes produced
during the highly stratified seasons could be expected to remain coherent
for longer time periods, as long as they remained above the pycnocline.
Large scale lateral discontinuities also occurred with lateral shear be-
coming evident by the displacement of either dye or waste plumes on either
side of the shear. These discontinuities were attributed to convergence

zones.

Midshelf Sites

A midshelf dumpsite for non-toxic chemical wastes exists 35 nm
(64 km) southeast of Cape Henlopen at 38°30'N, 74°15'W. (Fig. 14). Although
the site is now deactivated, acid-iron waste from the duPont Edgemoore

facility was dumped there from 1969 until early 1977, when the disposal

73


towards the sea bottom. Some vertical shearing of the remaining surface
plume by currents was noted.

The 106 Mile site already receives (or may receive in the near future)
a variety of waste types with widely varying physical and chemical character-
istics. These wastes may be separated based on their dispersion character-
istics into four groups:

Group 1 (American Cyanimid wastewater) has densities less than sea-
water, will not impact the ocean bottom and are most affected by horizontal
dispersion. Vertical mixing to the seasonal pycnocline may not be instan-
taneous although distribution of the waste throughout the seasonal mixed
layer will probably occur.

Group 2 (duPont Grasselli and Edgemoore wastewaters) has densities
which are close to seawater density and also will not impact the ocean
bottom. Vertical barge-wake mixing to the seasonal pycnocline (if present)
or deeper (if not present) is almost instantaneous; further dispersion is
horizontal. -

~

Group 3. (coal ash) has densities (particle densities) much greater
than seawater, with high sinking rates and will most probably impact the
bottom. This group is affected almost exclusively by its sinking rate
while barge wake mixing and horizontal dispersion are almost insignificant.

Group 4 (sewage sludge) composition varies widely but usually is
more than 95% water with a bulk density close to that of sea water. A
small fraction of the sludge is particulate material heavy enough to sink
to the sea floor quickly. The remainder is suspended or dissolved material;
the former sinks very slowly, the latter sinks only if its fluid density
is greater than sea water, coming to rest when dilution reduces it or

when it encounters the pycnocline.

79


INTRODUCTION

What is the health of the marine ecosystem in the coastal and offshore
waters of the northeastern United States? What are the impacts of man's
waste disposal activities on the living marine resources in this ecosystem?
These questions fall within the purview and are the concern of several
Federal agencies which have a general commitment to answer them. In the
Northeast, several elements of the National Oceanic and Atmospheric Adminis-
tration (NOAA), with expertise to respond to this commitment, have jointly
developed an integrated program, the Northeast Monitoring Program (NEMP), to
provide a scientific basis for the answers. Managers and investigators
involved in NEMP have selected a wide array of physical, chemical and biological
variables to measure for establishing baselines and for monitoring changes
at about 140 locations (Fig. 1), including areas where impact is expected,
as well as those that are thought to be currently relatively uncontaminated.

Determining and understanding changes in the health or quality of living
resources is not simple, because of the dynamic and complex nature of the
ecosystem and the variety of ways man can or does influence this system,
many of which are very subtle and difficult to measure. There are many
questions that need to be answered to fully understand how significant these
effects can be at the population or ecosystem level. A major area of
understanding that is yet incomplete is the role of physical oceanographic
processes and features in the transport, dispersion, and fate of pollutants

in the coastal and offshore waters of the northeastern United States.


Aikman, F. 1981. The effects of fresh water on
the shelf water pycnocline: a numerical study.
Paper presented at Middle Atlantic Physical
Oceanography Workshop, Univ. of Rhode Island,
Oct. 21-22, 1981.

Anderson, D. L-T., K. Bryan, A. E. Gill, and
R. C. Pacanowski. 1979. The transient
response of the North Atlantic: Some
mode? studies. J. Geophys. Res. 84(C8):
4795-4815. .

Four numerical experiments have been designed
to clarify the role of stratification and topography
on the transient response of the ocean to a change
in wind forcing. The geometry and topography
appropriate to the North Atlantic between the
equator and 50°N are used to make the study more
appropriate to a real ocean. In all four experi-
ments, zonally symmetric wind stresses are
"switched on' at the upper surface of a resting
model ocean. Two short experiments, 1 and 2, with
a duration of 100 days, are first discussed. These
are for a homoaeneous ocean with and without topog-
raphy. The response in the flat-bottomed case can
be described either in terms of planetary waves or
basin modes, but when topography is present, no
obvious wave propagation was identified. Higher-
frequency basin modes are detectable, but their
amplitude is much lower than that in the flat-
bottomed case. They are damped out on a time
scale of 0 days. Two longer experiments, 3 and
4, are then analyzed. These are the analogs of
Vand 2, but stratification was included. The
introduction of stratification for the ocean with
topography leads to a new, longer time scale, not
just for the baroclinic modes, but also for the
barotropic. Despite the presence of topography,
modal analysis was found useful in analyzing the
results. Propagation effects are analyzed, both
on the moderately fast time scale of internal
Kelvin waves and on the slow time scale of internal
planetary waves. Kelvin waves are apparent aTong
the equator, the northern boundary, and on the
eastern coast in the Gulf of Guinea from the
equator to 20°N. They are not clearly visible any-
where on the west coast. Planetary waves can be
detected in the interior both in the presence and
absence of topography. When topography is present
without stratification, the transport of the Gulf
Stream is reduced from 30 to 14 million tons per
second, This is a well-known result. With stratifi-

cation there is no significant difference in transport

between the case with or without topography.

Armstrong, R. S. 1979. Chapter 6. Bottom oxygen
and stratification in 1976 and previous years.
In: Oxygen Depletion and Associated Benthic
Mortalities in New York Bight, 1976. R. L.
Swanson and C. J. Sindermann (Eds.). NOAA
Prof. Paper 11, pp. 137-148.

* Comparison of climatological conditions, dis-

solved oxygen content and stratification data obtained

in 1976 with that obtained in previous years in the
New York Bight area.

Atwood, D., D. W. Brown, V. Cabelli, J. Farrington,
C. Garside, G. Han, D. V. Hansen, G. Harvey,
K. S. Kamlet, J. O'Connor, L. Swanson, D. Swift,

J. Thomas, J. Walsh, and T. Whitledge. 1979.
The New York Bight. In: Assimilative Capacity
of U.S. Coastal Waters for Pollutants. Pro-

ceedings of @ workshop at Crystal Mountain,
Washington, July 1979. £. D. Goldberg, (Ed.),
NOAA, Boulder, Colorado.

107

Azarovitz, T. R., C. J. Bryne, M. J. Silverman,
8. L. Freeman, W.G. Smith, S.C. Turner,
B. A. Halgren and P. J. Festa. 1979.
Effects on finfish and lobster. Chapter 13.
In: Oxygen depletion and associated
benthic mortalities in New York Bight,

1976. R. L. Swanson and C. J. Sindermann
(eds). NOAA Prof. Pap. No. 11, U.S.

Dept. Commerce, Rockville, Maryland

Barinov, A. A, and V. A. Bryantsev. 1972. A
volumetric statistical analysis of the Nova
Scotia shelf and Georges Bank water masses.
ICNAF Res. Bull. No. 9:21-25.

Barrett, J. R. 1965.
Cape Hatteras.

Subsurface currents off
Deep-Sea Res. 12:173-184.

Barrientos, C. S. and N. A. Pore. 1976. Storm
Surges. MESA NY Bight Atlas Monograph 6.
MESA NY Bight Project and NY Sea Grant
Institute, 44 p.

* — A historical summary analysis of storm
surges is offered-in this monograph. Major storms
affecting the Bight region were hurricanes of
September 1938 and 1960, extratropical storns of -
November 1950 and March 1962.

Beardsley, 8. C., W. C, Boicourt and 0. V. Hansen.
1976. Physical oceanography of the Middle
Atlantic Bight. Am. Soc. Limnol. Oceanogr.
Spec. Symp., Vol. 2:20-34.

Kinetic energy spectra from moored current
meters in the mid-Atlantic Bight reveal marked
differences in current variability between the
inner shelf and the outer shelf and slope regions.
The nearshore subtidal current variability appears
to be dominated by meteorological forcing. The
amplitude of the semidiurnal and diurnal tidal
peaks decreases in the offshore direction.

Shallow water records show little or no inertial
energy, while at the shelf break and over the
slope, inertial motion contributes significantly
to the current variance. A simple conceptual
model is presented to explain how intense winter
Tow pressure systems ("northeasters") drive strong
alongshore currents which are coherent over much
of the bight. A map of "mean" currents measured
in recent moored array experiments demonstrates
subsurface water flow along the shore toward the
southwest. The average currents generally
increase in magnitude offshore and decrease with
closeness to bottom. At most sites, the mean
current veers toward shore with increasing depth.
The alongshore volume transport measured at three
transects across the bight shows surprising
uniformity, considering the possible sources for,
discrepancy. This transport (order 2.0 X 105m°s">)
of water within the 100-m isobath implies a mean
residence time of the order 3/4 year. Much of the
shelf water observed flowing westward south of
New England must originate in the Gulf of Maine-
Georges Bank area.


Investigations of duPont Edgemoore (acid-iron) waste dispersion at
the 106 Mile site began in July 1977, because earlier in 1977 the disposal
operation was moved from the 35 Mile site to the 106 Mile site. ‘Acoustic
detection of the particulate phase of the waste during July 1977 showed
accumulations in regions of high density gradients with occasional pene-
trations of the gradient to depthsof 40 to 60m. Initial sinking rates
of the waste plume after release were 1-3 m-sec-l, with rapid decreases in
the rate by about 20 minutes. During winter conditions, when deep mixed
layers and an absence of seasonal thermoclines occur, the acid-iron waste
sank farther and appeared to remain in dense patches which did not show
rapid dispersion. Hydroscience (1978a, 1978b, 1979a) studied dispersion
of acid-iron waste at the 106 Mile site in May 1978, July 1978 and October
1978 and found minimum dilutions of 75,000:1 after 4 hours.

Horizontal dispersion of both the Grasselli and Edgemoore wastes
appeared to be generally enhanced (after initial barge-wake mixing) by
current shear, such as that noted during the July 1977 study when a warm
core Gulf Stream ring was located at the 106 Mile site. Csanady (1981)
in an analysis of several diffusion experiments clearly differentiates
between rapid "wake dispersion" caused by barge-generated eddies, and
"oceanic dispersion" caused by the mean shear and turbulence in the ocean.
Under stratified (summer) conditions, any further decrease in concentration
after the wake dispersion phase is completed, is a result of one dimensional
diffusion processes in the cross-plume direction. Csanady (1981) determined
that effective diffusivity values determined from the experiments were
orders of magnitude too low, meaning that other processes such as shear

diffusion must be responsible for the observed dilutions. A calculated

77


°, eo

"Os

“uoLzeoLsLyeays AZLsuap [euoseas HuLouatuadxa Jou seauy

°6, 20, °e, °9
c oe ec ¢
LL SL LZ

“BL aunBL4

od,

103


MIDDLE ATLANTIC BIGHT CIRCULATION (cont.)

Reference

Csanady (1980)
Han & Mayer (1981)

Bennett & Magnell
(1979)

Cornillon, Reed,
Spaulding & Swanson
(1980)

WES-COE (1982) @
Garrett (1974)

Csanady (1978)
Garfield (1978)
Qu, Beardsley, Mayer

Boicourt & Butman (1981)

Bush & Kupferman
(1980)

Schmitz & Owens
(1979)

Csanady (1974)

Area

Long Island coast

off Long Island

New Jersey coast

Georges Bank, Gulf of
Maine

Atlantic City to
Nantucket Island

Bay of Fundy, Gulf of
Maine

Middle Atlantic Bight
shelf
Middle Atlantic Bight
shelf

Middle Atlantic Bight

Middle Atlantic Bight

North Atlantic
(MODE area)

Gulf of Maine

88

Description

simple model to show
offshore winds could cause
longshore pressure gradient

tide and wind response
models based on current
meter records

use numerical model to
analyze current meter data

use SEASAT altimetry to
compare with 2-D vertically
averaged model

2-D storm surge model
(after Butler (1980))

examine normal modes
(after Platzman (1972))

steady-state, depth
averaged 'global' model
of shelf circulation

box model for transports

examine sub-tidal (wind-
forced & free wave)
current fluctuations in
current meter data

show that Csanady (1976)
model is sensitive to
alongshore wind stress
and pressure gradient

compare model results
(Bretherton & Karweit (1975))
with statistical properties
of mesoscale eddy field

from long-term moored
instrument data

linear model of aperiodic
motions over idealized
shelves


oa

i)

Dissolved Oxygen (ml/ I)
rN

0
On
Cc
°
=
Lo]
ot 2
= WH
ed
= 'e
zs
as
~>— 4
=
a
c
o
a
6
Figure 12.

Annual
Trend

New Jersey Shelf

[es a SO |

Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct

roses ve Bares ae Dery ergs Ds T T T T
ve

Range of Values

Cruise Average —| } for the Cruise

1 1 1 1 1 1 L 1 n 1 1

Seasonal cycles of dissolved oxygen concentration (m1-17 1) in
bottom waters (>20 m) and vertical density stratification
(surface minus subpycnocline ot difference) in New Jersey shelf
waters. From Armstrong, 1979.

56



TABLE 1.

Maximum, minimum, average and differences in bottom temperatures at 60 meters
depth (mid point of the cold pool) collected for 5 years (1977-1981) for

the southern New England and New York ship of opportunity transects (from
data collected by the NOAA/NMFS/Atlantic Environmental Group, Narragansett,
Rhode Island).

Transect Min. Avg. Timing Max. Avg. Timing |Ava.
Location Year |Temp.°C | Min Temp. |of Min.|Temp.°C|Max Temp.|of Max.| AT°C
1977 1.1 16.8
1978 1.6 13.6
Southern
New England 1979 1.9 14.9
1980 2.4 17.2
1981 3.3 12.0
2.1 Mid 14.9 Early | 12.8
March Nov.
1977 3.8 13.0
1978 3.8 12.0
New York 1979 3.8 12.0
1980 4.6 12.9
1981 4.7 11.6
4.1 Early 12.3 Late 9.1
June Nov.

52


41°

40°

39°

38°

37°

;
76°

Figure 4.

I ! |
75° 74° 73° 72°

Effluent plume from the Hudson-Raritan estuary as revealed by
surface salinity (parts per thousand). From a report of
results of cruise NEMP-81-07 of the GEORGE B. KELEZ, 3-9 June
1981, by C. E. Warsh, 18 June 1981.

14


Gulf of Maine

The thermal stratification of the waters in the Gulf of Maine follows
an annual cycle in response to seasonal heating and cooling by the atmos-
phere and direct solar insolation. The thermal influence on the stratifica-
tion is complemented by salinity changes in the surface waters due to the
annual variation in coastal fresh water runoff. Together the temperature
and salinity changes combine to yield a regular seasonal cycle of density
stratification in the Gulf of Maine.

In winter the Gulf of Maine is generally well-mixed to about 100 m
depth with temperatures of 2-5°C. This uniformity is due to convection
induced by surface cooling and strong winter winds. In extreme years
the mixing may extend to near bottom (>200 m). Below the cold mixed Tayer
normally there is a warmer (5-8°C) and saltier layer of bottom water that
originates over the continental slope and enters the Gulf through Northeast
Channel. During the spring, coastal runoff reaches a maximum and begins
to stratify the nearshore surface waters of the Gulf by decreasing the
salinity. Increased solar insolation then warms the surface layer and a
strong thermocline forms inhibiting vertical exchange and isolating a mid-
depth layer as a temperature minimum region of 4-5°C, remnant from the
past winter cooling. The temperature minimum slowly warms during the
summer. With the beginning of fall, atmospheric cooling begins to break
down the thermal stratification in the surface waters. By winter stronger
winds and continued surface cooling drive convection that mixes the upper

portion of the Gulf of Maine and begins again the annual hydrographic

cycle.

43


23 4 5 6 7 8910 N2 34 15 617
0 Se ae ae SO
FE 2 2a
Z SS = 7
504 22) 16: 4
20:
1004
~ 18
no
(oa
w= =1604 2
- 100fm r 16
WW 10:
2 2004 .
~~ “AIT L
14
fa 2504 72° 70° ,
a
W
2 3005 7 2
MORMAC ARGO
350-44 78-07
10°
7/29/78
10._NM 8 /
490 ——
Figure 10. Vertical section of temperature (°C) showing thermocline

STATION NO.

development in shelf and slope waters. From Cook and

Hughes, 1978.

47



waste was less dense (1.020 g'cm-3) and tended to remain in the upper
waters. Upon mixing with seawater, the duPont waste produces a white floc
which was found (under laboratory conditions) to settle at 0.5 m-min7!,

After 17 hours the duPont waste at 10 m was diluted to 12,500:1, while the
American Cyanimid waste at 10 m was only diluted to 2,500:1 after 17 hours.
These differences were again probably caused by the differences in the
initial densities of the wastewaters relative to seawater. Dye concentra-
tions decreased rapidly in the first 5 hours and then began to asymptotically
approach a constant value.

Hydroscience (1978f, 1979c) studied the dispersion of American
Cyanimid Warner wastewater and found dilutions after 4 hours of 25,000:1
in May, 14,000:1 in July, and 9,200:1 in October 1978. Acoustic back-
scattering data (Orr and Hess, 1978) indicated that Grasselli waste tended
to reside in the mixed layer above the seasonal thermocline in the summer
season. Winter data showed deeper penetration and uniform vertical dis-
tribution of the Grasselli waste to greater than 60 m depth (Orr et al.,
1980).

Falk and Gibson (1977) reported on a dispersion study which was con-
ducted by EG&G Environmental Consultants for duPont in September 1976 at
the 106 Mile site using dyed Grasselli waste and a series of fluorometers.
This study was done during calm sea conditions and with a well developed
seasonal thermocline. Within 2 minutes of dumping, Grasselli wastewater
dilution was 5,000:1 and increased to 15,000-30,000:1 after 17 hours.
Similar results were reported by Hydroscience (1978c, 1978d, 1979b) for

Grasselli waste dumped in May, July and October 1978.

76



Iselin, C. O'D. 1939. Some Physical factors
which may influence productivity of New
England's coastal waters. J. Mar. Res.
2(1): 74-85,

* Discussion of physical factors such as

salinity, temperature, large scale mixing

mechanisms, and eddies which affect the pro-
ductivity of New England's coastal waters.

Iselin, C. 0'0. 1955. Coastal currents and the
fisheries. Deep Sea Res. 3 (Supp].) :346-357.

Johnson, 0. 8. 1973. The seasonal density
structure and circulation on the continen-
tal shelf. EOS Trans. Amer. Geophys.
Union 54(4):316-317,

Johnson, R. E. 1976. Circulation Study near
Cape Henry, Virginia, using lagrangian
techniques. Tech. Rep. 21, Inst. Oceanogr.,
Old Dominion Univ., Norfolk, Virginia.

Johnson, Ronald E. 1981. Lagrangian circula-
tion study near Cape Henry, Virginia. In:
Chesapeake Bay Plume Study - Superflux 1980.
p. 175-197. NASA Conference Publication
2188. J. W. Campbell and J. P. Thomas (Eds)
516 p. Scientific & Technical Information
Branch, National “Aeronautics and Space
Adninistration, Wash., DC.

Summary

A study of the circulation near Cape Henry,
Virginia, has been made using surface and seabed
drifters and radar-tracked surface buoys coupled
to subsurface drag plates. Drifter releases
were conducted on a line normal to the beach just
“south of Cape Henry. Surface drifter recoveries
were few; wind effects were strongly noted. Sea-
bed drifter recoveries a1] exhibited onshore mo-
tion into Chesapeake Bay. Strong winds also
affected seabed recoveries, tending to move
them farther before recovery. Buoy trajectories
in the vicinity of Cape Henry appeared to be of
an irrotational nature, showing a clockwise ro-
tary tide motion. Nearest the cape, the buoy
motion elongated to almost paralle] depth con-
tours around the cape. Buoy motion under the
action of strong winds showed that currents to
at least the depth of the drag plates substanti-
ally are altered from those of low wind con-
ditions near the Bay mouth. Only partial evidence
could be found to support the presence of a clock-
wise nontidal eddy at Virginia Beach, south of
Cape Henry.

Joseph, E. B., W. H. Massman and J. J. Norcross.
1960. Investigations of inner continental
shelf waters off lower Chesapeake Bay.
Part I. General introduction and hydro-
graphy. Chesapeake Sci. 1:153-167.

138

Kangas, R. E. and G. L. Hufford. 1974, An
upwelling rate for Massachusetts Bay.
Jour. Geoph. Res. 79(15): 2231-2236.

Contours of time series bathythermograph
data taken at the Boston light vessel station
over several years (1964-1971) indicate that
upwelling occurs in Massachusetts Bay during
most summers. Cold more saline water is noted
near the nottom progressing upward through

the water column. Upwelling rates for 1971

of 2.0 X 10-" cms"? and 5 X 10-4 cm s~l were
computed from the upward migration of iso-
therms and by the equations of Yoshida (1955),
respectively. The upwelling period (sumer)
coincides with the time of predominate south-
easterly to westerly winds. A definite de-
crease in sea level height observed during the
summer of 1971 may have been due to the off-
shore wind-driven transport of surface water.

Kao, A. F. 1975. A study of the current
structure in the Sandy Hook-Rockaway
Point transect. Mar. Sci, Res. Center
Tech. Report. Mar. Sci. Res. Center,
SUNY, Stony Brook, L. I., NY

Kao, T. W. 1980. The dynamics of ocean fronts.
The Gulf Stream. J. Phys. Oceanogr. 10:483-
492.

The establishment and maintenance of the
mean hydrographic properties of large-scale
density fronts in the upper ocean is considered.
The dynamics is studied by posing an initial
value problem starting with a near-surface dis-
charge of buoyant water with a prescribed den-
sity deficit into an ambient stationary fluid
of uniform density. The full time-dependent
diffusion and Navier-Stokes equations with
constant eddy diffusion and visosity coeffi-
cients and for a constant Coriolis parameter
are used in this study. Scaling analysis re-
veals three independent length scales of the
problem, vis., a radius of deformation of in-
ertial length scale Ly, a buoyancy length scale
hg and a diffusive length scale hy. Two basic
dimensionless parameters are formed from these
length scales: the thermal (or more precisely,
the densimetric) Rossby number, ‘RS = Lo/ho

and the Ekman nunber E = (hy/ho)?. The gov-
erning equations are then suitably scaled and
the resulting normalized equations are shown

to depend on E alone for problems of- oceanic
interest. Under this scaling, the solutions
are similar for all ®i,sufficiently large. It
is also shown that 1/ROis a measure of the
frontal slope, so that“Ro is large for all
oceanicdensity fronts. The governing equa-
tions, in the form used in a previous paper by
Kao et al. (1978), are solved numerically and
the scaling analysis is confirmed. The solution
indicates that an equilibrium state is estab-
lished. The front can then be rendered station-
ary by a barotropic current from a larger scale
alongfront pressure gradient. In that quasi-
steady state and for small values of E, the
main thermocline and the inclined isopycnics
forming the front have evolved together with
an intense alongfront jet and a crossfront

(or cross-stream) circulation with surface dis-
charge toward the front and return flow at
greater depth. Conservation of potential vor-
ticity is also obtained in the light water pool.


Hansen, 0. VY. 1977. Circulation. MESA NY
Bight Atlas Monograph No. 3, N.Y. Sea
Grant Inst., Albany, NY. 23 p.

* This MESA monograph extracts and summarizes
archived and original source current meter,
sea-bed drifters and Euleran method data in an
attempt to give an exact picture of circulation
in the Bight. The major feature of Bight
circulation is a relatively slow flow to the
southwest over most of the outer continental
shelf. There is evidence that this general
pattern may be altered or even reversed for
periods of up to 3 months during the sunmer
over New Jersey's shallow shelf. Indications
of a clockwise eddy exist in the inner Bight
influenced by the Hudson/Raritan estuary,
angular coastlines and the Hudson Shelf Valley
topography. Mapping of the inner Bight tends
to be inadequate due to temporal and spatial
variability from tides and wind actions.

Harding, J., S. Larson, T. Laevastu, and K. Rabe.
1976. Ocean atmosphere interactions off the
northeast coast of North America. Am. Soc.
Limnol. Oceanogr., Spec. Symp. 2:35-43.

* This article summarizes data not given by the
author in past literature, including objective
analysis of large scale effects of sea-air
interactions in the New York Bight-Middle Atlantic
continental shelf, response of surface air
properties to sea surface properties (micro-
scale analysis of interaction within 10 m of
surface); and the effects of energy feedback

from the ocean to atmosphere.

Hardy, C. C., E. R. Baylor, and P. Moskowitz.
1976. Sea surface circulation in the north-
west apex of the New York Bight - with
appendix: Bottom drift over the continental
shelf. NOAA Tech. Memo. ERL MESA-13. 132 p.

Hargis, W. J., dr. 1981. A benchmark multi-
disciplinary study of the interaction
between Virginian Sea. In: Chesapeake
Bay Plume Study - Superflux 1980. NASA
Conference Publication 2188. J. S. Campbell
and J. P. Thomas (Eds.), 516 p. Sci. and
Tech, Information Branch, National Aeronautics
and Space Administration, Washington, D.C.

Harrison, W., M. L. Brekmer and R. B. Stone.
1964. Nearshore tidal and nontidal currents,
Virginia Beach, Virginia. U.S. Army Corps
of Engineers Tech. Memo. 5, 20 p.

Harrison, Wyman. 1966. Partial correlation model
for waters of the southern portion of the Middle
Atlantic Bight, U.S.A. Proceedings of the
10 Conf. on Coastal Engineering, 4 p

The model holds for waters of the Atlantic
continental shelf of the United States between
Cape Henlopen, Delaware, and Cape Hatteras,
North Carolina. It iS based upon correlations
between environmental driving forces (winds and
runoff) and surface and bottom drift inferred
from drifter recoveries.

131

Harrison, W., J. J. Norcross, N. A. Pore, and
E. M. Stanley. 1967. Circulation of shelf
waters off the Chesapeake Bight - Surface
and bottom drift of continental shelf waters
between Cape Henlopen, Delaware and Cape
Hatteras, North Carolina. June 1963-
December 1964, ESSA Prof. Paper No. 3,

82 p.

Part I. - The coastline between Cape Cod,
Mass., and Cape Hatteras, N.C., is known as the
Middle Atlantic Bight. The configuration of this
coastline permits distinctton of two smaller bights -
New York Bight in the north and Chesapeake Bight
in the south. The mouth of Chesapeake Bay is,
found at the apex of the Chesapeake Bight.
Coastal or shelf waters considered in the Study
extend from the shores of the Chesapeake Bight
to the 183-m isobath. These shelf waters are
of interest to fisheries biologists because a
nunber of important fish spawn in them; species
whose early life stages are spent in nursery
grounds of Chesapeake Bay or other coastal
embayments. The present Study was designed to
reveal possible modes of transport of young
fishes from the offshore spawning sites to the
nursery grounds,

Part I summarizes much of the earlier
research on continental shelf waters off Middle
Atlantic Bight. Included are descriptions of
the seasonal distribution of temperature and
salinity, as affected by atmospheric conditions
and river discharge, and the surface and bottom
circulation of shelf waters. Since 1951,
knowledge of the drift of bottom water has
been enhanced by use of the Woodhead seabed
drifter. Recovery of seabed drifters released
off the Chesapeake Bight during 1963-1964
indicated shoreward drift of bottom water which
at times was ortented toward Chesapeake Bay.

Part II.-Beginning in June 1963 and lasting
for 17 consecutive months, drift bottles and sea-
bed drifters were released from U.S. Navy aircraft
over the continental shelf off the Chesapeake
Bibht. Temperature and salinity variations across
the shelf off Chesapeake Bay were determined in
15 monthly shipboard surveys. Results obtained
did not indicate significant changes in the sur-
face flow patterns compared to previous findings,
but a complex pattern of surface circulation was
noted during the surmer of 1964. The effects of
winds, runoff, and characteristics of the thermal
structure of shelf waters are offered as explana-
tions for variations in the surface flow.

Bottom drift of shelf waters off Chesapeake
Bight, although exhibiting areal and monthly
variations, tended toward the southwest, irre-
spective of the season and direction of the
surface flow. The influence of Chesapeake Bay
circulation on continguous bottom waters of the
shelf was evidenced by the recovery of seabed
drifters in the Bay or near its entrance. The
direction of the inferred bottom drift toward
Chesakeake Bay appeared to be related to changes
in river discharge and seasonal prevailing winds.
The rate of bottom drift was estimated to be
highest when the water column was not thermally
stratified and to increase with increasing dis-
tance from shore.


The slope water mass has been thought of as a mixture of shelf water
and Gulf Stream water, the masses which abut it on the shoreward and sea-
ward sides, because its temperature and salinity ranges lie in between
those of its neighboring masses.. Recent work by Fairbanks (1982) using
oxygen isotope ratios to identify source areas of Atlantic coastal water
masses revealed that slope water mainly is derived from the Labrador Sea
with some Gulf Stream water mixed in (via warm core rings). The average
motion of this water mass is much like that of the shelf water, parallel to
the bathymetry and toward the southwest. Aperiodically, the slope water
area is invaded by meanders of the Gulf Stream or warm core rings separated
from the Stream, either of which radically change the local water mass
Properties and circulation at any given location.

Circulation of the surface layer of shelf and slope water is strongly.
influenced on short (multi-day) time scales by weather conditions in the
overlying air mass. Summaries of long-term mean weather conditions have
been prepared for the Middle Atlantic Bight and Georges Bank (including
the Gulf of Maine) by Williams, et al. (1977) and Godshall, et al. (1980).
Together, the two summaries adequately cover the geographic area of concern
to this study in terms of surface wind, visibility, air temperature (Georges
Bank) and superstructure icing. Earlier atlases for the North Atlantic
(Meserve, 1974; U.S. Naval Oceanographic Office, 1963; and Naval Weather
Service Detachment, 1976) include our area of interest only in their broader
Portrayal of mean monthly or seasonal conditions.

According to Godshall, et al. (1980), the northern part of our area
of interest falls between the normal summer and winter locations of the

Polar Front, yielding two distinctly different wind regimes in the two_


Hicks, D.C. and J. R. Miller. 1980. Meteoro-
jogical foreing and bottom water movement
off the northern New Jersey coast. Est. &
Coast. Mar. Sci. 1980 11:563-571.

+ Archive temperature, salinity and density
data from NODC and standard weather observations
at JFK airport and Atlantic City NJ from NCC
were analyzed to determine atmospheric forcing
of oceanographic conditions at _a section across
the New Jersey continental shelf (39 40-40N,

72 45-74W). Additional data from Monterey
Beach were used to examine extent of upwelling
events in the surf zone. Prolonged southerly
winds created upwelling and moved "cold pool”
water near shore. Prolonged north winds
created downwelling conditions. Time scale of
1 day was seen in response of shelf waters to
meteorological functions.

Hicks, Steacy D. 1963. Physical oceanographic
Studies of Narragansett Bay, 1957 and
1958. Spec. Sci. Report: Fisheries No. 457.

Hilland, J. E. and R. S. Armstrong. 1980.
Variation in the shelf water front
position from Georges Bank to Cape Romain
in 1978. Annis biol. Copenh. 35:46-50.

Hilland, J. E. 1981. Variations in the shelf
water front position in 1979 from Georges
Bank to Cape Romain. Annis biol. Copenh.
36 :34-36.

Holland, W. R. 1978. The role of mesoscale
eddies in the general circulation of the
ocean ~ numerical experiments using a
wind-driven quasi-geostrophic model. J.
Phys. Oceanogr. 363-392.

Results from a two-layer, quasi-geostrophic,
general circulation model of the ocean with fine
horizontal resolution are presented. As in Holland
and Lin (1974a, b), mesoscale eddies spontaneously
arise due to instabilities in the oceanic currents,
giving rise to transient ocean circulations
that reach a statistical equilibrium. In these
final equilibrium states, the interaction of the
eddy field with the mean is examined, and it is
shown that the eddies determine the character of
the large-scale mean flow. In particular, the
eddies act to limit the amplitude of the mean flow
in the upper ocean, are responsible for a downward
energy propagation that fills the deep sea with
eddy energy, and create a downward momentum flux
which is responsible for the creation of deep,
time-mean, abyssal gyres that are an important
component of the vertically averaged mass transport
in the ocean.

Three new aspects of the mesoscale eddy prob-
Jem are discussed. First, the Holland and Lin
(1975a, b) results are extended to highly non-
Tinear free jets, a simple but more realistic
treatment of the Gulf Stream as the source for
mesoscale eddy energy. Second, bottom friction is
examined as the likely mechanism for energy dis-
sipation in a quasi-geostrophic turbulent flow;
lateral dissipation enters as an important en-
strophy sink but not as an important energy sink.
Finally, the usefulness of the quasi-geostrophic
nature of the model is demonstrated; only one-tenth
of the computer time needed for two-layer primitive
equation experiments is required for quasi-
geostrophic ones with comparable resolution.

133

Holland, W. R. and A. D. Hirschman. 1972.
A numerica] calculation of the circulation
in the North Atlantic Ocean. J. Phys.
Oceanogr. 2:336-354,

A series of numerical experiments are
carried out to simulate the three dimensional
Circulation in the North Atlantic Ocean and to
examine the dynamics therein. The calculations
are partly diagnostic in that the density field
is not predicted but is given from observations.
The main predicted quantities are the velocity
and pressure fields.

The results of the basic experiment are
compared with observations. The surface currents
are quite similar to observations based upon
ship drift data, and the surface pressure field
is nearly identcal to the height of the free
surface constructed from a level of no-motion
hypothesis. The deep pressure variations are
nowhere flat or level, however, and the pre-
dicted deep currents are quite complex. They
are, in fact, strongly controlled by botrom
topography and tend to follow f/II contours,
where f is the Coriolis oarameter and II the depth.
The Gulf Stream transport is quite large,
reaching a maximum value of 81 X 10%m?sec-*
despite the lack of important inertial effects
in the western boundary current. Subsidiary
experiments show that this large transport
value results from an important interaction
between the variable density field and bottom
topography in the western North Atlantic.

When in one experiment the density field was a
homogeneous one and in another the depth was
constant, the maximum transports in the western
boundary current were only 14 and 28 X 10®m°sec-*
respectively.

Other experiments show that the details
of the wind-stress distribution are unimportant
when the density field is known; the density
field contains most of the information about the
Jong term wind driving. For example, when the
wind stress is set equal to zero everywhere (but
the density field is maintained in its observed
configuration), the Gulf Stream transport is
reduced by only 5%. Thus, the pressure torques
associated with bottom topography provide the
main vorticity input. Finally, it is shown
that the results discussed in the basic experi-
ment aré not very sensitive to the details of
the density field used in the calculation. When
these data are highly smoothed and used in a
subsidiary calculation, the important features,
such as the enhanced transport in the Gulf
Stream and the topographic steering of currents
jn the deep ocean, are unchanged.


shelf, sometimes moving the cold pool off the bottom and causing it to
bulge seaward, leading to "calving" (Whitcomb, 1970 and Wright, 1976).

Bathymetric features such as the Hudson Shelf Valley and the submarine
canyons which underlie the outer edge of the cold pool at several locations,
from Corsair Canyon at the eastern edge of Georges Bank to Norfolk Canyon
at the southern end of the Middle Atlantic Bight can affect the cold pool.
Flow in the canyons can cause movement in the position of the cold pool.
According to Mooers et al. (1979) down canyon transport of cold pool water
was observed along the southwestern side of Wilmington Canyon. In contrast
to this, Han and Niedrauer (1981) observed that cold pool water did not
sink into the Hudson Shelf Valley, but rather stayed at the same level
as on the surrounding shelf. Nevertheless, bottom water flow in the
canyons and shelf valleys should act to displace the cold pool either
onshore or off.

At the southern edge of the cold pool, near Cape Hatteras, where the
shelf is narrow, the Gulf Stream entrains both surface shelf water and
subsurface cold pool water (Ford et al., 1952; Fisher, 1972; and Kupferman

and Garfield, 1977).

Seasonal and Interannual Variations

Depending on geographic location, the cold pool attains its minimum
temperature in early spring to early summer (Table 1). Off southern
New England the minimum is usually recorded in mid-March (1.1-3.3°C,mean
2.1°C), but off New York it is in early June (3.8-4.7°C, mean 4.1°C).
Off southern New England, the minimum cold pool temperatures ranged from
1.1°C to 3.3°C averaging 2.1°C in 1977-81, while off New York they ranged
from 3.8°C to 4.7°C, averaging 4.1°C (Table 1).

51


Bank and Nantucket Shoals, bounding estuarine effluent plumes, and bordering
upwelling areas in a coastal active band throughout the Middle Atlantic Bight
and Gulf of Maine. Most of these fronts can be detected by satellite infra-
red sensors.

Density stratification occurs seasonally throughout the region of interest,
except in areas of strong tidal mixing such as central Georges Bank, Nantucket
Shoals, and the eastern end of Long Island Sound. The presence of a thermo-
cline during summer months acts as a barrier to the descent of many of the
wastes presently dumped at sea, reducing the available mixing volume to the
surface mixed layer.

The cold pool is a relatively isolated layer of cool water underlying
the thermocline and mixed layer in the Middle Atlantic Bight each summer and
early fall. Replenishment of dissolved oxygen in this layer is quite slow
because of the density stratification of the thermocline. In 1976 a large
portion of this layer suffered critically low oxygen concentrations and high
mortality of benthic organisms resulted. Oxyaen-demanding pollutants may
have been a minor contributing factor, but the event was mainly caused by
early stratification and unusual circulation patterns.

Field studies of dispersion of dumped wastes have been conducted at the
12-Mile Sewage Site and the Acid Dump Site in the New York Bight apex, the
35-Mile Dumpsite off Delaware, and the 106-Mile Site. Typically, settling
velocities, mixing rates, and diffusivities were determined for selected
waste materials in these studies.

Development of conceptual and numerical models for the region of interest
has progressed mostly along general lines, covering broad areas. Few models
are being or have been developed to deal specifically with the trajectories

and dispersion of waste materials dumped in coastal and offshore waters.



Rhode Island Sound
Flow patterns
J. Geophys.

Shonting, D. H. 1969.
square kilometer study 1967:
and kinetic energy distribution.
Res. 74:3386-3395.

A square kilometer array of se]f-recordina
current meters was placed in Rhode Island Sound
for 13 days in the summer of 1967 to monitor
quasi-continuously small-scale current motions
above and below the sharp seasonal pycnocline.
The surface flow appeared stronaly isolated from
the lower layer by the pycnocline. Strong
influence of the semi-diurnal tide was observed
in both layers; however, a dominant mean flow to
the WSW occurred in the upper layer, whereas
.the lower layer showed more random and rotary
character. Instantaneous currents within the
array show occurrences of highly meandering
and unsteady motions a few hundred meters in
dimension. The kinetic eneray of mean motion
and the turbulent (or eddy) kinetic eneray of
the upper layer were about 4 to 5 times that of
the bottom layer.

Shonting, D. H. and G. S. Cook. 1970. On the
seasonal distribution of temperature and
salinity in Rhode Island Sound. Limnol.
and Oceanogr. 15(1):100-112.

sigaev, I. K. 1978. Intra-year variability
of geostrophic circulation on the con-
tinental shelf off New England and Nova
Scotia. ICNAF Selected Papers No. 3.

From the analysis of charts of dynamic
topography based on data collected in 1963-73,
seasonal types of the geostrophic current fields
on the New England and Nova Scotia shelves are
described and intra-year variations in the
circulation pattern considered. The various
types are characterized by quasi-stationary
ayres of zones of risina and sinking water,
some of which coincide with important biological
events, such as the spawning of herring on
Georges Bank in September and the spawning of
silver and red hake along the southern slopes
in early sumer.

Simpson, J. H., C. M. Allen and N.C. G. Morris.
1978. Fronts on the continental shelf.
J. Geo. Phys. Res. 83(C9):4607-4614.

* — The authors report a model of frontal regimes
in the ocean based on available turbulent kinetic
energy from tidal currents and wind stress and on
buoyancy flux input at the surface. Model valida-
tion was with sea surface temperature measurements
from an airborne radiometer and velocity measure-
ments using radio tracked drogues on 18-19 July 1973.

Earlier drogue measurements near fronts are discussed.

While the mean positions of fronts are predicted
well by the made1, detailed structure is not.

Simpson, J. H. and D. Bowers. 1981, Models of.
stratification and frontal movement in shelf
areas. Deep-Sea Res. 28(7A):727-738.

159

smith, J. D. and C. E. Long. 1976. The effect
of turning in the bottom boundary layer
on continental shelf sediment transport.
Mem. Soc. Royale Sci. Liege 6(10):369-396.

* "In this paper 2 simple time-dependent
analytical model with a Tinearly increasing
eddy viscosity near the sea bed and a constant
one in the interior, is developed and compared
to current meter data collected in recent years
during studies of circulation on the Washington
continental shelf. The results indicate that
reduction of the turbulent diffusion coefficient
due to flow stratification and the effects of
density-induced pressure gradients in the
interior of the water column must be included

in the mode? in order to explain the salient
features of the measured velocity hodoaraphs.
Reasonable estimates of these parameters in-
dicate approximately 18 degrees of turning
between the center of the water column and the
sea bed in a layer about 30 m thick. When
combined with the observation that the direction
of the vertically averaged velocity closely
parallels that of the isobaths, this yields a
ratio of offshore to lonashore sediment trans-
port of nearly 1:3."

Smith, K. L., dr., C. H. Clifford and 6. T.

Rowe. 1974." Sediment oxygen demand in
an outwelling and upwelling area. Tethys.
6:223-230.

* In situ analysis is given of oxygen demand
of sediments from New York Sight outwellings
and California current upwellings to evaluate
the influence or organic enrichment on benthic
carbon utilization and to provide a basis of
comparison. Studies reveal that enrichment
‘increases the oxyaen demand of sediments.

"The mud sediments of the outwelling area were
high in oraanic carbon and infaunal abundance
and biomass whereas in the fine sediments of
the upwelling, organic carbon, infaunal abund-
ance and biomass were lower. ‘Oxygen demand, in
both areas were equivalent."

Smith, R. A., J. R. Slack, and R. KX. Davis.
An oilspill risk analysis for the Mid-
Atlantic outer continental shelf lease
area. U.S. Geological Survey Open-File
Report 76-451.

1976.

An oi1spill risk analysis was conducted to
determine relative environmental impacts of
developing of1 in different regions of the Mid-
Atlantic Outer Continental Shelf lease area. The
study analyzed probability of spills, likely path
of pollutants fron spills, and locations in space
and time of recreational and biological resources
likely to be vulnerable. These results are com-
bined to yield estimates of the overall oilspill
risk associated with development of the lease area.


Field experiments to determine the trajectories and dispersion of
waste materials have been conducted with particular classes of wastes at
specific dump sites. The short-term behavior of dumped wastes depends
a great deal upon the characteristics of the site at which they are
dumped and on the nature of the wastes. Accordingly, the results of

field studies and their applicability are limited.

12-Mile Sewage Sludge Site

The 12 mile dumpsite, situated in about 25 m water depths in the
apex of the New York Bight, about 15 km off Long Island and about 20 km
off Sandy Hook, New Jersey (Fig. 14), is in a highly variable marine
environment. The water column in the vicinity of the site undergoes
regular seasonal changes in stratification because of heating and cooling,
wind mixing and influx of low salinity water from the Hudson-Raritan
estuary. Average currents are toward the south-southwest, but vary widely
under the influence of local wind forcing and stratification.

Summaries of currents and hydrography in the waters of the inner
portion of New York Bight (Hansen, 1977; Han and Niedrauer, 1981; EPA,
1978) show long-term mean flows to the southwest, ranging from 5-6 cm+sec~1
(0.1 knot) in the surface layer to less than 2 cm-sec7! (0.04 knot) in the
bottom water. On shorter time scales the currents are stronger and highly
variable in-direction and speed. Wind-driven surface currents can occur
in any direction and compensating flows in bottom waters can result from
some wind conditions (Charnell, 1975; Nelsen et al., 1978; Hicks and Miller,
1980; and Bennett and Magnell, 1979), producing either shoreward advance and

upwelling of bottom water off New Jersey and in the Hudson Shelf Valley, or

68


been made that imply that the process of upwelling occurs either continuously
or intermittently. However, direct observations of upwelling have not
yet been made.

Lagrangian bottom drifters released along the Northeast Channel
(Lauzier, 1967) show a zone of divergence implying upwelling of bottom water
along the northeastern edge of Georges Bank. Current meter moorings placed
in an array across the northern slope of the bank have shown evidence of a
divergence off the northern edge (R. J. Schlitz, personal communication)?
The meters located below 80 m on two moorings in water depths of 200 m and
220 m all showed components of current away from the bank (north). The
average speeds were between 2 and 6 cm-sec~! for the duration of the records,
up to 47 days. In addition to evidence from direct measurements of current,
Pastuszak, et al. (1982) have concluded that there are indications of up-
welling near the northeastern edge in nutrient and hydrographic data col-
lected over the period of one year.

One mechanism that may induce upwelling has been proposed by Garrett
and Loucks (1976) from a study of upwelling near the southwest corner of
Nova Scotia. Centrifugal forces generated by strong tidal currents associ-
ated with features of bottom topography of smal] radius of curvature produce
upwelling independently of the current direction. Both conditions are
found at the eastern end of Georges Bank where the bottom contours turn
from an east-west to a north-south orientation. A second mechanism was
proposed by Loder (1980) in his model of rectification of tidal currents
along the northern edge of the bank, in which cells develop in the cross-
isobath direction involving flow onto the bank along the bottom above the

60 m isobath.

2 Dr. Ronald Schlitz, U.S. Dept. of Commerce, NOAA/NMFS, Woods Hole,

MA 02543

23


flow to the west due to the geostrophic force balance. This current
parallels the westward wind stress which caused the initial setup. Storms
located over the land, however, cause eastward wind stresses setting up a
large alongshore Pressure gradient force which causes large current oscil-
lations but little net alongshore flow. These storms cause Ekman transport
away from shore and cause sea levels to fall along the coast. Bishop and
Overland (1977) showed that during the winter season wind-driven circula-
tion predominates on the shelf while during the summer, density driven
currents are more common.

Many workers have found that these meteorologically forced subtidal
currents increase in magnitude away from the coast and decrease near
bottom. Boicourt and Hacker (1976) showed near-bottom currents of between
12 and 36 cm-secu!, increasing in a seaward direction. They also showed
that cross-shelf currents may be enhanced by near-bottom onshore flow
along the outer shelf in response to offshore Ekman flow at the surface
under certain wind conditions. Beardsley et al. (1976) showed that
currents veered shoreward closer to bottom, suggesting that near-bottom
materials may move shoreward, in agreement with the earlier sea bed drifter
work already discussed.

Seasonal stratification due to the development of a pycnocline in
shelf water has several implications for the current structure, response
and sediment transport of the region. Patchen et al. (1976) determined
for the apex of New York Bight that weak stratification resulted in the

entire water column responding strongly to the wind, while response was

limited to the upper stratified layer when a thermocline was present.
Han et al. (1980) showed a decoupling of currents above and below the

pycnocline in the New York Bight, with near-bottom currents varying from

66


Lavelle, J. W., P. E. Gadd, G. C. Han, P. A. Mayer,
W.L. Stubblefield, 0. J. >. Swift,
R. L. Charnell, H.R, Brashear, F. N. Case,
K. W. Haff and C. W. Kunselman. 1976.
Preliminary results of coincident current
meter and sediment transport observations
for wintertime conditions on the Long
Island inner shelf. Geophys. Res. Letts:
3(2):97.

We have observed late fall and winter
bedload sediment transport and the overlying
current field in ridge and swale topography

on the inner continental shelf south of Long
Island, and can report movement of bed material
at a water depth of 20 m to a distance of
approximately 1500 m after several storm events.
Movement over an 11-week observation period was
Yonashore and oblique to the ridge crest at the
experimental site. Currents were also predomin-
ately longshore, but long term averages demon-
strate that a vertical shear existed in the
fluid motion. Although the number of sediment
transport "events" suagested by the current
meter data is nearly balanced in eastward and
westward directions, both estimates of transport
from current speeds and sand tracer dispersion
patterns show that several westward flowing
events dominated the transport during a two and
one-half month period. A quantitative upper
bound of 31 cm/sec on the threshold velocity
for sediment movement in this size range i
also set by the data.

Lavelle, J. W., D. J. P. Swift, P. E. Gadd,
W. L. Stubblefield, F. N. Case, H.R
Brashear, and K. W. Haff. 1978. Fi
weather and storm sand transport on the
Long Island inner shelf. Sedimentology 25:
823-842.

Lavelle, J. W. and D. J. P. Swift. 1982.
Near-shore currents measured in ridge-and-
swale topography off Long Island, New York.
J. Geophys. REs. 87(c6) :4190-8194.

Eightegn near-shore current records within an
area 11 km? on the Long Island inner shelf have
been examined for indication of small-scale topo-
graphic influence. In the frictionally influenced
near-shore water column, currents over the 39-day
records are generatly oriented slightly clockwise
of the longshore direction toward the principal
axis of the local ridge-and-swale topography.

This orientation angle is largest and closest to
the local topographic axis when semidiurnal tidal
currents dominate other flows, a result which may
suggest that tidal currents play a role in molding
the local topography. Viscous tidal current
theory for a constant depth surface describes the
observed dependence of the semidiuran] (Mz) tidal
current ellipticity and ellipse orientation on
depth. The inferred vertical eddy viscosity
coefficient ranges from 5 to 35 cn*/s.

Lavelle, J. W., R. A. Youna, D. J. P. Swift
and T. L. Clarke. 1978. Near bottom
sediment concentration and fluid velocity
measurements on the inner continental shelf,
New York. J. Geophys. Res. 3:6052-6062.

142

Lear, D. W., M. L. O'Malley, W. C. Muir and
G. Pence. In press. Environmental
effects of sewage sludge at the Phila~
delphia dumping site. In: Ecological
Stress and the New York Bight: Science
and Management, G. F. Mayer (Ed.).
Estuarine Research Federation.

The Philadelphia sewage sludge disposal site
is located about 70 km east of Ocean City,
Maryland. Sludge has been dumped at this
site since 1973, and the environmental effects
of the practice have been under detailed
observation since that time. The site
showed no evidence of departures from
typical, temperate mid-shelf conditions
prior to the onset of sludge dumping.
Since then, trends of environmental
modification and degradation have appeared
in areas contaminated by sludge-derived
materials. The changes seen limited to
the ocean bottom environment and include
increased concentrations of metals in
organisms, elevated metals and total
organic carbon levels in sediments,
changes in abundance of some species,
apparent mortalities of molluscan
shellfishes, unique occurrences of

sewage bacteria, and appearance of
pathological conditions in endemic
crustaceans,

Circulation
Pesticide

Leetma, A. and H. Stonmel. 1972.
on the continental shelf.
Monit. Jour. 69:3380-3384,

Lesht, B. M. 1978. Field measurements of the bottom
frictional boundary layer in the New York Bight.
ERL MESA-28, NOAA, Wash., OC, August 1978.

A detailed field study of near sea floor fric-
tional boundary layer of the inner continental shelf
in the apex of the New York Bight was undertaken to
present a coherent picture of boundary layer processes
affecting sediment transport. High resolution,
simultaneous measurements of turbidity were made in
order to correlate sediment transport with the flow.
Mave activity is discussed and relationships between
wave time scales and mean flow turbulence presented.
The study provides a basis for modeling long term
average observations and allows for a more accurate
assessment at sediment transport.

Lettau, B., W. A. Brower, Jr. and R. G. Quayle,
1976. Marine Climatology. MESA New York
Bight Atlas Monograph 7. N.Y. Sea Grant
Inst., Albany, NY 239 p.

* — The climatology of the New York Bight is
presented in narrative and atlas form, based
on data collected by ships of various registry
travelling through the study area, US. Coast
Guard Tight stations, and seven other coastal
land stations. The narrative section “utilizes
selected data as examples and illustrations of
the seasonal variation of meteorological
parameters." It is intended as an overview
indicating the range and scope of the climatic
variation, The atlas is a detailed presenta-
tion of wind, visibility, present weather, sea
level pressure, temperature, cloud, and wave
data in the form of maps and graphs.


4l°4

40°

POINT PLEASANT,

MANASQUAN

Oo |
39 bj
CAPE MAY
T
75° 74° 73° 72° 7I°
Figure 13. Dissolved oxygen concentration (m1-17)) in bottom water in the

New York Bight during August - September 1976. (From Swanson
and Sindermann, 1979).

59


indirect indication of effluent plume characteristics (Pape, 1981). Nine
releases of surface drifters during the. April 1979-March 1980 period showed
predominantly out-of-bay and southward trajectories along the DelMarVa
shore to the Chesapeake Bay entrance and beyond. After one deployment
(July 31) drifters passed Cape Hatteras and were recovered along the coast
of North Carolina. Some northward motion was indicated by a few drifters
on four releases, and on one release (November 15) all the drifters moved
north outside the bay entrance.

A study of 129 satellite clear-sky images, both color and infrared,
conducted by Fedosh and Munday ( 1982 ) showed that the turbidity plume
from Delaware Bay often was manifested in two bands. One band was located
off Cape May (north of the bay) and the other off Cape Henlopen (south of
the bay). The Cape May turbid zone was the larger of the two, usually
filling about 70% of the bay entrance. Its configuration was highly
variable, often extending southeastward, but occasionally northeastward
along the New Jersey coast. The Cape Henlopen turbidity plume was more
linear in shape and about one-tenth as large. Its orientation was character-
istically southeastward, veering southward along the coast.

Most of the plumes detected remained within 20 km of the Delaware
coast and extended southward as much as 40 km. None of the plumes reached
the acid waste disposal site located 60 km southeast of Delaware Bay. The
thermal images revealed a different plume pattern, occasionally showing
three bands corresponding with the turbidity pattern and at other times

showing only a single warm plume near Cape Henlopen.

16



The ring shown in cross section in figure 8 apparently also has inter-
acted with the shelf water in a relatively common manner. Water from the
cold pool lying beneath the thermocline on the shelf (<10°C) has been
removed and warm slope water (>12°C) has been thrust up on the upper
slope by the ring. Such exchanges can involve slope water that has re-
ceived wastes from dumping operations at the 106 mile site, which may
be thrust well up onto the shelf.

Other workers have continued to study the production of warm core
rings in succeeding years (1976-1980) and have shown 3 to 6 rings occur-
ring per year at the 106 mile dumpsite (Mizenko and Chamberlin, 1979a,
1979b; Mizenko and Chamberlin, 1981; Celone and Chamberlin, 1980;
Fitzgerald and Chamberlin, 1981, 1982 (in press). Although the occur-
rence of the rings in the slope water and at the 106 mile site are com-
monplace, there is apparently no regular seasonality or periodicity to
them.

Of the three principal water masses which may occupy the upper
portion of the water column of the 106-Mile Dumpsite, Sargasso Sea
water in warm core rings provides the greatest mixing depths (depth
to thermocline) for dissolved or slowly settling wastes. Dumping
near the center of a warm core ring would provide for isolation from
interaction with shelf water or slope water and would allow the greatest
dilution to occur in a water mass having a relatively low average
density of marine organisms. Dumping in the periphery of a ring should
be avoided, however, to avoid the risk of mixing the waste-bearing water
with slope water or shelf water, where the population densities of

organisms are greater.

33


Pease, T. £. 1969. A study of temperature and
salinity changes along the northern New
Jersey coast. N.Y. Univ. Dep. Met.
Qceanog. Geophys. Sci. Lab. Rep. TR
69-7, 51 p.

W. D. and $. G. Ackleson. 1981. Remote
sensing of optically shallow, vertically
inhomogeneous waters: A mathematical mo-
del. In: Chesapeake Bay Plume Study-
Superflux 1980. p. 283-299. NASA Confer-
ence Publication 2188. J. W. Campbell and
J.P. Thomas (Eds.), 516 pp. Scientific
and Technical information Branch, Aeronau-
tics and Space Administration, Wash. OC.

Philpot,

A multiple-layer radiative transfer model
of a vertically inhomogeneous, optically shallow
water mass is briefly described. This model is
directed toward use in remote sensing of water pro-
perties. Some preliminary results and qualitative
predictions are presented.

Posmentier, E. S. and R. W. Houghton. 1978.
Fine structure instabilities induced
by double diffusion in the shelf/slope

water front. J. Geophys. Res. 83(C10):
5135-5138.
* Analysis of temperature-salinity data

from 13 stations across the shelf/slope front
southeast of Long Island between 39.8 N, 71.5 W
and 40.5 N, 72.2 M taken on R/V CAPE HENLOPEN in
Nay 1977. ‘Intervals of negative stability are
found in the TS diagram at the frontal zone.
Analyses indicate double-diffusion mixing with
salt fingering as the mechanism responsible.

Posmentier, £. S. and R. W. Houghton. 1981.
Sprinatime evolution of the New England
Shelf break front. J. Geophys. Res. 86(C5):
4253-4259.

The shelf break frontal shape and T-S relation-
ships in the frontal vicinity have been observed to
undergo a transition in the spring. It is shown that
this transition should result from two simple assump-
tions: (1) during the early spring, the offshore
density gradient becomes reversed in a layer of
intermediate depth; and (2) the front is cravita-
tionally stable. Observations south of Nantucket
preceding and following the transition during 1979
illustrate the metamorohosis from a monotonically
sloping front to @ convoluted shape which delineates
two layers of shelf and two of slope water. The
convoluted shape of both the front and the T-S
curves after the transition are found to be consistent
with the observed density oradients if it is further
assumed that the front is Margules-type with a
velocity discontinuity of 5 cm/s.

153

Pratt, S. D., $. 8. Saila, and Polgar. 1972.
Dredge spoil disposal in Rhode Island
Sound. Univ. of Rhode Island Tech. Rep.
2:48 p.

* Technical report which discusses dredge
spoil disposal in Rhode Island Sound. The re-
port contains general information on the spoil
disposaT dumpsite, characteristics of the phy-
sical environment of the area, and reviews some
direct effects of spoil dumping on marine
animals and the benthic invertebrates of the
Sound.

Pritchard, P. W. 1955. Estuarine circulation
patterns. Proceedings of the Aner, Soc.
Civil Eng. 81: Sep. No. 717, 11 pp.

Proni, J. R., H. M. Byrne, F. C. Newman and D. J.
Walter. 1977. Acoustic imaging of the New
England shelf-slope water mass interface.
Nature, 269:790-791.

+ — This is an analysis of data taken from June 15-23,
1976 by the NOAA ship George B. Kelez along the New
England continental shelf. Measurements were made
along three tracklines. Profiles using XBT and CTD
were obtained at regular intervals. Acoustics were
used to detect the interfaces associated with the
intrusion of cold New England shelf water into the
warmer slope water during this period. It was
found that the shelf-slope water transition zone
apparently fluctuates significantly in location

on a time scale of a few days.

Proni, J. R. and D. ¥. Hansen. 1981, Dispersion
of particulates in the ocean studied
acoustically: The importance of gradient
surfaces in the ocean. P. 161-173. In:
Ocean Dumping of Industrial Wastes. (B. H.
Ketchum, D. R. Kester and P. K. Park, Eds.)
Plenum Press, New York and London.

Knowledge of the rate of dispersion of
particulate matter dumped in the upper ocean and
of the processes governing that dispersion is
fundamental to an understanding of the effects
of dumping on the ocean environment. Accurate
chemical dilution rates of dumped material
cannot be determined without a knowledge of the
spacial distribution of ocean dumped material
and the way in which that distribution changes
with time. Acoustical methods offer one approach
to studying ocean dispersion of dumped material.
Acoustical results presented herein show some
of the complicated effects which gradients in
oceanic parameters, such as temperature and
density, produce in the dispersion of particulate
matter dumped in the ocean.


Maximum cold pool temperatures occur when the vertical stratification
of the water column is destroyed during fall overturn. The warmest
temperatures off southern New England (11.6-13.0°C, mean 12.3°C) precede
the maximum temperatures off New York by an average of only 20 days (usually
in November). Differences between seasonal maximum and minimum temperatures
are larger off southern New England (almost 13°C) than off New York
(about 9°C).

Role of Convective and Advective Mechanisms

Traditionally the cold pool has been described as a stationary parcel
of remnant winter water that slowly eroded away during the summer and
early fall. Then, because the coldest part of the cold pool in summer
often was located off New York, it was suggested that the source of the
cold water was within the Middle Atlantic Bight. Recent analyses of more
detailed thermohaline data and long-term current meter measurements have
shown a slow (1-3 cm-secTM!), mean flow of the cold pool from the north-
east to the southwest (Beardsley et al., 1976 and Mayer et al., 1979).

Data collected in the cold pool from ships of opportunity along two
transects in the Middle Atlantic Bight (south across the shelf along 71°W
and southeast across the shelf from New York) also indicate that pulses
of cooler water are advected southwestward between these two transects
until mid-June with a speed consistent with current meter observations.

With the onset of spring warming and development of thermal stratifi-
cation, vertical mixing processes essentially cease between the cold pool
and the surface. As an indication of how weak this vertical mixing is,

estimates of vertical velocities for subsurface fronts in slope water

53


The estuarine circulation of lower Chesapeake Bay involves two-layer
flow, with the upper layer discharging low-salinity water onto the contin-
ental shelf while the lower layer moves higher-salinity shelf water into the
bay (Pritchard, 1955). Generally, over a series of tidal cycles and as a
result of estuarine circulation, freshened bay water exists at the surface
on the southern side of the bay mouth (Cape Henry) and is deflected to the
right by the earth's rotation. Boicourt (1973) in a synoptic study following
Hurricane Agnes showed that the outflow turned to the south and flowed as
a quasi-qeostrophic jet along the Virginia-North Carolina coast with greatest
thickness nearshore, with the halocline shoaling to a high-shear lateral
front 8-15 km offshore.

For a recent, time-series perspective, Munday and Fedosh (1981) examined
81 dates (1972-80) of Landsat images using enhancement and density slicing
techniques and showed that the Chesapeake Bay plume usually lies off the
Virginia coast south of the bay mouth. Southwesterly winds spread the plume
eastward over a large area. Ebb tide images (compared to flood tide images)
showed a more dispersed plume.

The remote sensing aspects of the SUPERFLUX experiments (Campbell and
Thomas, 1981) further confirmed the two-dimensional structure of the plume
with respect to salinity, chlorophy11, suspended solids and crude phyto-
plankton assemblages in much greater detail and more synoptically than the
traditional sampling used to estimate its character. Of particular interest
was the identification of patches of higher or lower salinity water in the
plume (Kendall, 1981).

Waters emanating from Chesapeake Bay to the contiguous shelf are not

homogeneous. Oertel and Wade (1981) demonstrated the lack of congruence

19


Ketchum, Bostwick H. and Nathaniel Corwin, 1964,
The persistence of "winter" water on the
continental shelf south of Long Island, New
York, Linmol. Oceanogr. 9(4); 467-475.

The deep water on the continental shelf
south of Montauk Point, Long Island, remains
cold throughout the summer. Since this cold-
water pool is surrounded by warmer water, it
appears to be formed in the winter and to per-
sist, with only gradual modification, for
several months.

The temperature and salinity of the water
in this area have been observed on 20 cruises
made during a 3-year period. The cycle of
temperature is described. The salinity changes
in the deep water as it gradually warms are
used to evaluate qualitatively whether the
temperature change in each year was associated
with admixture of high-salinity warmer off-shore
waters or lower-salinity, warmer surface waters.

The average salinity of the water on the
continental shelf was closely correlated with
the 6-month average river flow of the Connecti-
cut River, and it is shown that the salinity
can be predicted to within error of estimate
of approximagely 0.3% from this river flow.

Ketchum, B. H. and W. L. Ford. 1952. Rate of
dispersion in the wake of a barge at sea.
Trans, Am, Geophys. Union. 33(5):680-684.

Ketchum, B. H. and D. J. Keen. 1955.

Cape Cod and Chesapeake Bay.
to 3:346-357.

Summary - The depth mean salinities for the waters
of the continental shelf between Cape Cod and Chesapeake
Bay show a seasonal variation in the concentration of
The spring and the winter accumulations
are about the same, but about 25% more river water. is
The total volume of fresh water
in spring and winter is equivalent to that produced by
The extra
accumulation in summer is equal to half a year's flow,
and reflects, in part, the fact that the high spring

river water.
present in the summer.

the rivers in about one and a half years.

flows of two successive years are present_on the
shelf at this time.

There is a decrease in the average content of river
water in the direction of the flow of the coastal current,
in spite of the addition of river water along its course.
It is concluded that considerable transport of river

water and of salt normal to the coast is necessary.

horizontal mixing coefficients normal to the coast are
computed from the seasonal changes in salinity. They
range from 0.58 to 4.96 x 10® cmé/sec, with the values
for the decrease in salinity from spring to summer being
smaller than those for the increase from sumer to winter
At both times, the values decrease with

conditions.
increasing depth and distance from shore.

The accumulation
of river water over the continental shelf between
Deep-Sea Res. Suppl.

iho

Ketchum, B. H., A. C. Redfield and J. C. Ayers.
1951. The oceanography of the New York
Bight. Papers in Physical Oceanography
and Meteorology. 12(1) 1046. Massachu-
setts Institute of Technology and Woods
Hole Oceanographic Institution.

Six cruises were made at different seasons
to survey the hydrographic conditions in the
inner part of the New York Bight, where the
effluent from the Hudson and other rivers enters
the sea. The distributions of salinity, tem-
perature, oxygen and iron are described.

Sea water diluted with river water varies
greatly in distribution from the more conmon
pattern with the diluted water confined to a
narrow band along the New Jersey shore, to a
pattern with the diluted sea water widely
distributed over the surface.

On four of the six cruises, when the
river flow was fairly great, the distribution
patterns were well defined. Dynamic calcula-
tions indicated that the current velocities
required to maintain these distributions in
steady state were possible. Both widespread
and confined patterns of distribution were
included.

Ketchum, B. H., R. F. Vaccaro, and N. Corwin.
1958. The annual cycle of phosphorus and
nitrogen in New England coastal waters.
J. Mar. Res. 17:282-301.

Klemas, V. G., R. Davis and R. D. Henry. 1977.
Satellite and current drogue studies of
ocean-disposed waste drift. J. Water
Poll. Control Fed. May 1977. 757-763.

Klemas, V. and W. 0. Philpot. 1987. Remote
sensing of ocean-dumped waste drift and
dispersion. P. 193-211 In: Ocean Dumping
of Industrial Wastes. Eds. 8. H. Ketchum,
0. R. Kester and P. K. Park. Plenum Press,
New York and London.

The drift and dispersion of sixteen acid
waste plumes 64 km off the Delaware coast were
investigated using Landsat imagery, current
drogues and ship data. The waste plumes
imaged by Landsat were found to be drifting
at average rates from 0,59 km fir-1 to 3.39 km
hr“? into the southwest quadrant. The plumes
seemed to remain above the thermocline which
was observed to form from June through August
at depths ranging from 13 m to 24m. During
the remainder of the year the ocean at the
test site was not stratified, permitting wastes
to mix throughout the water column.

The magnitudes of plume drift velocities
were compatible with the drift velocities of
current droques released over a 12 month period
at the surface, at mid-depth and near the
bottom. However, during the stratified warm
months, more drogues tended to move in the
north-northeast direction, while during the non-
stratified winter months a southwest direction
was preferred.

Rapid waste movement toward shore occurs
primarily during storms, particularly north-
easters. Duirng such storms however, the plumes
are rapidly dispersed and diluted. The plume
width was observed to increase at a rate of
about 1,5 cm sec~! during calm sea conditions,
yet attain spread rates in excess of 4 cm sec”
‘on windy days. These results indicate that by
the time a waste plume would reach shore, di-
lution would be at least one million to one.


Impact of Ocean Disposal

The work of O'Connor, Okubo, Champ, and Park (1981) can be viewed as
a "global" model for addressing the question of what will happen if sewage
sludge is dumped at the 106 Mile dumpsite. It can be viewed as a global
model because it addressed the "big picture" in terms of what will happen.
They are not concerned with specific details or developing new models.
Rather, they determine what the existing information base can tell them
and then piece together what they hope to be a consistent picture. The
various components they use can range from observations and estimates up
to actual model results. A product of this type of modeling is the

indication of the areas where more research is needed.

86


Oceanographic Office and the National Earth Satellite Service of NOAA

have prepared weekly charts of the Gulf Stream front position.

Nantucket Shoals Front

Most of the information on the hydrographic characteristics of Nan-
tucket Shoals was collected in a series of cruises during May, July, and
September 1978 (Limeburner and Beardsley, 1979). Along the eastern and
southern side of the shoals the general characteristics of a tidally-
generated front (boundary of well mixed area) were found at about the 40
m contour. The shallower region was always homogeneous since the mixing
caused by the high tidal currents overcomes the heating and fresh water
inputs that tend to produce vertical stability. Outside the 40 m contour
the frontal structure was complicated by localized upwelling regions.
These were spatially variable, but generally found in an area 15 km wide
and 50 km Tong. Although general frontal characteristics were seen in the
temperature, salinity, and density fields, the vertical difference of
density defines the well-mixed zone most clearly. Within the shallow
area of the shoals the vertical density differences were always 0.1 g.1-1
or less while in the stratified area values up to 4.0 g.17! were found in
duly.

After fall overturn of the water column the fronts along the eastern
and southern side of the shoals disappeared. This was due to the atmos-
pheric cooling and increased wind stress. Limeburner (1979) found well-
mixed conditions both on Nantucket Shoals and to 100 m depth in the Gulf

of Maine from data collected in January and March.

40



once enough is known of the forcing factors, of the flow factors,

of the control factors, then a prediction can be made about the effects

of a perturbation of some part of the system on some other part of

the system. There may never be a complete model of the New York

Bight, including the circulation, the geology, and biology, the ecology,

the benthic biology, the phytoplankton, the zooplankton and all of

their interactions. But that doesn't say that a model can't be
useful; it doesn't have to be complete, but it does have to be
realistic. Approximations or estimates can be used for some of the

‘unknowns' and the results checked against reality."

These comments are quite appropriate as one reviews the state of
modeling the marine environment of the northeastern United States. If
one were to pinpoint a major failing of models (and modelers) for the
region, it would have to be that they are not available when major environ-
mental decisions for the marine system have to be made. This is not to
indicate that the researchers have somehow failed, but rather to point
out an area that has not been addressed adequately by modelers; providing
our decision makers with the best scientific information available on
which to base their judgments. What are needed are models that can
answer the many "what if" questions that decision makers need to consider,
predictive models that have a firm basis in the real world.

From descriptions of the features and processes in the preceding
chapters, it is quite apparent that the marine environment off the north-
eastern U.S. is quite complex. It is so complex that the process of
"building" models for the various systems is difficult, because many of
the underlying processes and interactions are not sufficiently understood.

However, much modeling work has been done, and some of it is quite useful.

81


Jersey shelf would have been below 2 ml-t7! Gn August, with essentially
totally depleted oxygen developing over some portions of the shelf. Off
Long Island, average minimum concentrations would have been reduced to
about 2.3 ml-1-!. Diaz (1979) found that from February through June of
1976, storm activity over the New York Bight was well below the norm. This
condition would also have reduced replenishment to the bottom waters
because of decreased vertical exchange with surface waters from a lack of
mechanical mixing. Disruption of the normal southwesterly currents
because of abnormal winds were considered to have diminished replenishment
because of reduced flushing by advection and to have enhanced utilization
by concentrating the bulk of oxygen-demanding material over the New Jersey
shelf (Mayer et al., 1979; Han, et al., 1979). Added to these factors

was increased utilization of oxygen because of the extensive bloom of the
dinoflagellate Ceratium tripos. Located in the upper levels of the cold
pool during spring and early summer, respiration by this population repre-
sented a significant increase above normal jn oxygen demand (Malone, 1979).
As the bloom collapsed in mid-summer, dead dinoflagellates coated the
bottom,and the decay of this mass placed further demand on the oxygen
supply in the bottom water (Mahoney, 1979).

The extensive and persistent hypoxia and mass mortalities off New
Jersey in 1976 (Fig. 13) resulted from the combined occurrence of all the
factors described above. More limited hypoxic events developed in the
summer of 1974 and in the fall of 1968 and 1971. In each of the latter
two years summer was prolonged and overturn of the water column by autumnal
cooling was delayed, so that the length of the season of stratified water

conditions was extended (Armstrong, 1979). Although all of these cases

58



Table 2 presents a summary of modeling activities that have been completed
and/or are underway. The table is organized roughly in accordance with
the pertinent features and processes discussed in the previous chapters.

It would be impossible in the space allotted to discuss a significant
fraction of the models listed in Table 2. . Instead, six modeling activities
were chosen as examples to be discussed. This is not to say that those
picked are the best. Rather, these particular activities serve as good
examples that can be used to point out good aspects of modeling as well

as problem areas.

Diagnostic Modeling in New York Bight

The term diagnostic as applied to modeling means that not all of
the typically dependent variables are calculated. Instead, one or more
of the dependent variables are specified, and the other dependent
variables are calculated based on this specification. A good example of
this type of modeling is the work of Han, Hansen and Galt (1980) and Han,
Hansen and Cantillo (1979) applied to the New York Bight. They specified
the currents at the boundaries-and the interior density field, then
"interpolated" the currents in the interior using the appropriate hydro-
dynamic equations. Galt (1980) provides a clear description of this
"interpolation" procedure. This method is very useful for deriving a flow
field over a region from a few point current measurements. One problem
with this model is that it is very data intensive and is only as good as
the data it uses. Also, the model is only useful during relatively steady
conditions, and it is not a predictive model.

A possible alternative to requiring field data as input would be

to use a coarse-grid predictive model over a much larger region. Then

82 4


Celone, P. J. and J. L. Chamberlin. 1980. Anti-
cyclonic warm-core Gulf Stream eddies off
the northeastern United States in 1978. Annis.

Biol. Copenh. 35:50-55.

Chamberlin, J, L. 1978. Unusual offshore distribu~
tion of cold Atlantic Shelf water during the
spring and summer of 1978. Coastal Oceanog.
and Clim, News 1(1):1-2.

1975, Assessment of offshore
Physical oceanography, geological
ERL

Charnell, R. L.
dumping
oceanography, chemical oceanography.
NESA-1, 90 p.

* _ A data report which examines the physical,
geological, and chemical oceanographic features
of the New York Bight and their relationship to
waste and sewage disposal in the area. The in-
vestigation includes studies of ocean currents,
sea floor topography, sedimentation, methods of
sewage disposal, and the chemical composition of
sewage.

Charnel1, R. L., G. Han. W. L. Stubblefield. D. J. P.
Swift, H. Mofjeld, Peter £. Gadd, J. W. Lavelle,
H.-R. Brashear, F..N, Case, C. S. kunselman.,

1976. Preliminary results of coincident current
meter and transport observations for winter time
conditions on the Long Island inner shelf, Georphys.
Res. Letters. 3(2): 97-100.

Data report which discusses the "preliminary re-
sults of an experiment recently completed in the New
York Bight to directly measure offshore cohesionless
sediment and its inmediate forcing mechanism, the
overlying water velocity field."

Charnell, R. L., D. M. Hansen. 1974. Summary
and analysis of physical oceanography data
collected in the New York Bight Apex, MESA
Report No. 74-3. 44 pp.

Charnel?, R. L., and D. S. Mayer. 1975, Water
movements within the Apex of the New York
Bight during summer and fall 1973, NOAA
Tech. Memo. EORL MESA - 3. 29 pp.

Charney, J. G. 1955.
inertial boundary layer.
Sci. 41:83-92.

The Gulf Stream as an
Proc. Nat. Acad.

Chase, J. 1955. Winds and temperatures in relation to broa
strength of Georges Bank haddock. Journ. Du Conseil.
21(1):17-24,

117

Chase, J. 1959. Wind induced changes in the water
colunn along the east coast of the United
States. J. Geophys. Res. 64:1013-1022.

* Data report which presents data from eleven

lightships stationed along the U.S. late in 1955.
The survey extended from Frying Pan Shoals

Lightship (about 145 miles southwest of Cape

Hatteras) to Ambrose Lightship just north of Sandy

Hook, New Jersey.

Salinity, temperature and surface pressure

was taken to determine what effect if any, did

wind pattern have on the water column at these

lightships. It.was found that two types of changes
in the water column at certain lightships are
linked to the wind pattern. In one type there is

a replacement of the whole water column, whereas

in the other there is a fluctuation in the thick-

ness of the upper layer.

Surface salinity along the east

Chase, J. 1969.
Deep-Sea Res.

coast of the United States.
16 (Supp1.): 25-29.

Salinity determinations daily at 12 light-
ships from Savannah to Portland ‘during 1956-
1967 are descriptively analyzed using decadal
means. Seasonal cycles appear well-defined.
Annual minima generally follow spring thaw and
run-off.

1979. The coastal longshore pressure

Chase, R. R. P.
Temporal variations and driving

gradient:

mechanisms. J. Geophys. Res. 84(C8):
4898-4904,
Cheney, R. E. 1978. Oceanographic observations

in the western North Atlantic during FOX 1,
May 1978. Tech. Note 3700-79-78, V. 5 U. S.
Naval Oceanographic Office, Washington, 0.C.

Chervin, M. B. and Malone, T. C. 1979. The pro-
duction and fate of phytoplankton size frac-
tions in the plume of the Hudson River, New
York Bight. Limol. Oceanogr. 24(4): "683-696.

* The causes of seasonal blooms of net plankton

in Feb-March, and nanoplankton in June-July are

explained by changes of water columm stability,
phytoplankton growth, and copepod grazing. Sampl-
ing was done at six stations in the New York Bight

from September 1973 through March 1978.

Net plankton blooms as correlated with
periods of weak stratification.

Nanoptankton dominated during the summer
when primary productivity and copepod biomass
reached their seasonal maxima. These small cells
were almost entirely consumed before they could
sink from the surface layer.


Cresswell, G. M. 1967. Quasi-synoptic monthly
hydrography of the transition region between
coastal and slope water south of Cape Cod,
Massachusetts. WHOI Tech. Rot. 67-35.

Crist, R. W. and J. L. Chamberlin. 1979, Bottom
temperatures on the Continental Shelf and
Slope south of New England during 1977.
Biol., Copenhagen. 34:21-27,

Annis.

Csanady, G. T. 1973.
at the edge of the continental shelf.
Oceanog. 3(3):274-279.

Wind-induced baroclinic motions
J. Phys.

In a two-layer model of stratified fluid flow,
motions in the internal mode are governed by the
distribution of an equivalent depth hg. For a typical
continental shelf, the distribution of he with distance
from shore may be closely approximated by two straight-
line distributions patched at the shelf break, one
of constant slope and one of constant (equivalent)
depth. For such a simple model the forced response
to a suddenly imposed wind stress (in the internal
mode) is easily calculated. The component of the
wind stress perpendicular to shore produces a step-like
feature of the thermocline at the shelf, and a long-
shore Ekman drift gradually reducing to zero at the
coast from the infinite ocean value far offshore.

Wind stress parallel to the shore produces a thermo-
cline step and a longshore jet at the shelf break,
both of linearly increasing amplitude (in time),

and an onshore or offshore Eknan drift, again reducing
to sero at the coast but having the infinite-ocean
magnitude far offshore.

Csanady, G. T. 1974.
continental shelf.
357-371.

Barotropic currents over the
J, Phys. Oceanogr, 4:

We study below with the aid of linearized
equations, but using a quadratic bottom friction
jaw, the barotropic forced (aperiodic) response to
wind stress or external pressure gradient of
varjous ‘simple continental shelf models. The
frictionless response to longshore wind stress
shows many of the characteristics of the classical
"coastal jet" problem but is complicated by depth
variations, mainly because of the generation of
vorticity over a sloping bottom. Positive vorti-
city is generated where the depth increases to
the left of wind (in the North Hemisphere) and
negative vorticity where the depth gradient is
opposite. Thus, in a deep guif separated from
the open ocean by a shallow bank (in the Gulf

of Maine, for ezample), a double-gyre circula-
tion tends to be established.

Friction places a definite limit on the
maximum velocities which are produced by a storm
of given intensity, the limit being more or less
independent of depth. For typical shelf condi-
tions the time of establishment of frictionally
controlled flow is 2 few times 104 seconds,
Tonger where the establishment of geostrophic
balance requires larger influx of water into
the shore zone (e.g., in a wide gulf). Outside
the shelf break, frictionally controlled flow
is never established by any Storm of realistic
duration. The response remains essentially of
the frictionless transient type with a progressive
development of a coastal jet that intensifies
with time. A realistic, combined model may be
obtained by patching a coastal jet over the open
ocean to frictionally controlled flow over the
shelf. This reveals the further slow change in
surface level over the shelf, which, however,
does not significantly influence the frictionally
controlled flow pattern.

A comparison of the theoretical results with
observations in the Gulf of Maine suggests that
the observed double-gyre circulation known to. be
most intense in May) is a barotropic response to
northeasterly wind stress, It is hypothesized
that these winds dominate the air-sea momentum
exchange early in the season because air blowing
off the continent is much warmer than the sea
surface and produces only iow stresses.



at an average speed of about 6 cm-sec7! (Halliwell and Mooers, 1979).
Meanders reaching amplitudes of around 150 km or more often detach from the
Stream and close into rotating masses of water called Gulf Stream rings or
eddies.

Warm core rings form in slope water from meanders on the left (shore-
ward) side of the Gulf Stream (Fig. 6). The detached meanders close into
clockwise (anticyclonic) rotating masses of water with measured velocities
from as slow as 30-50 cm/sec (Saunders, 1971) to as fast as 140 cm/sec
(Cheney, 1978). These rings have a warm core because they enclose Sargasso
Sea water that moved shoreward with the originating meander. Greatest in
area near the sea surface, when newly formed they have ranged in diameter
from about 150 to 230 km and may reach depths of over 2000 m. Unlike Gulf
Stream meanders which move in the direction of the Stream, warm core rings
move in the slope water in a direction opposite to that of the Stream, at
average speeds up to about 15 cm/sec over extended periods. However, they
have been observed to stop or move in other directions for days or even
several weeks. Because most warm core rings seen off New England and the
Middle Atlantic coast have formed southeast of Georges Bank, where Gulf
Stream meanders often reach high amplitude, many have been absorbed back
into the Gulf Stream near their place of origin within a few weeks or
inonths after formation, by encountering one of these meanders. Those which
escaped such destruction and reached the longitude of Cape Cod usually have
persisted for a few more months until eventually resorbed by the Gulf
Stream at the latitudes of Virginia, where the Stream runs close to the
continental slope. The frequency distribution of ring longevity provides
more direct evidence that warm core rings tend to be either short- or long-

lived. The production rate of rings occurring in the slope water west of

27


Parker, B. B. and R. B. Pearce, 1975.
The response of Massachusetts Bay to
wind stress. MIT Sea Grant Program Rep.
MITSG 75-2. Massachusetts Inst. of Technol.,
Cambridge, MA. 02139. 107pp.

The effect of atmospheric stability on the
wind stress coefficient (or drag coefficient),

Cy, of the commonly used quadratic law is de-
monstrated. The method of determining values
for Cp is essentially a "wind set-up" method
using Doodson filtered tidal records from
Boston and Sandwich, Massachusetts and simi-
larly filtered wind and barometric

Pressure data, The mean values for Cp for the
three stability groups are: 1.10X10-" for
stable conditions, 1.40X10-3for neutral con-
ditions, and 1.84X10~ for unstable conditions.
The wind set-up method has been objected to
for various reasons, but all these objections
are fairly well answered for as far as this
particular investigation is concerned.
Excellent correlation exists not only between
Boston-Sandwich sea level differences and

the component of wind stress along the longi-
tudinal axis of the bay (which is necessary
to carry out the above method), but also
between Boston-Portsmouth sea level differences
and the onshore component of wind stress.
Filtering Boston, Sandwich, Portsmouth, and
Eastport, Maine tidal records results in very
similar non-tidal sea level curves even after
Pressure correction, This fact, combined
with the several hour lag between changes in
the onshore wind stress component and sea
Tevel changes at Boston, implies that the
Gulf of Maine has an important effect on
Massachusetts Bay.

Wind data at Boston is used for this study
but it is corrected for the frictional effect
of land using the result of comparisons with
other wind stations around the bay. This has
apparently not been done for many wind set-
up investigations and is perhaps one reason
why Cp's from wind set-up methods have usually
been larger than from other methods.

Wind stress was generally much greater in
the winter of 1971 than in the sunmer, not
only because of generally higher wind speeds,
but also because of greater atmospheric in-
stability and denser air. There is however,
reason to believe that wind-driven currents
(in the upper layer of water) are greater in
the summer due to thermal stratification.
Current data off Salem harbor generally support
this contention and also indicate the existence
of internal waves.

A sceptical look is also taken at the basic
quadratic law and an alternative approach is
Suggested.

Parr, A. E. 1933. A geographical ecological
analysis of the seasonal changes in
water along the Atlantic coast of
the U.S. Bull. Bingham Oceanogr.
Collect. 4:1-90.

152

Pastuszak, M., W. Redwood Wright, and D. Patanjo.
Unpubl.” One year of nutrient distribution
in the Georges Bank region in relation to
hydrography, 1975-1976. ICES C. M. 1981/
c:7 Hydrography Committee. International
Counc. Expl. Sea, Copenhagen.

A series of nine cruises were conducted in
the Georges Bank region between July 1975 and
August 1976. The sampling included measurement
throughout the water colunn of temperature, salinity,
dissolved oxygen, nitrate, orthophosphate, and
silicate. The distribution of the variables and
their annual cycle are described for the waters on
Georges Bank and in the adjacent areas of the Gulf
of Maine to the north and over the continental
slope to the south.

Patchen, R. C., and B. W. Gottholm. 1981.
The response of the shelf to hurricane Belle-
August 1976. NOAA Tech. Rep. NOS 89, 36pp.

On 10 August 1976 Hurricane ge11e passed
‘through the New York Bight; the data set in-
cluded meteorological information from the
National Weather Service, water level information
from the National Ocean Survey, and current meter
and Salinity/Temperature/Depth (STD) information
from the Marine Ecosystem Analysis Program.
Hurricane Belle can be classified as a fast-moving
storm translating over a two-layer density struc-
ture. The temporal and spatial responses to the
hurricane were determined by spectral and resi-
dua? techniques. The STD information and the
temperature records obtained at the current meter
locations indicate that a cooling and mixing of
the surface waters was observed at stations to
the right of the storm, and that only weak mixing
was observed at stations directly in the path of
the storm. At current meter locations on deeper
areas of the continental shelf (greater than 55 m)
the baroclinic response of a generation of internal
inertia-gravity waves in the lee of the hurricane
can be seen in the two layers. For stations of
the shallower area of the shelf (less than 55 m),
a strong barotropic response indicated by the
generation of localized quasi-geostrophic baro-
tropic Rossby waves, 18 to 20 hours after the
hurricane entered the New York Bight, is ob-
served. The data compared favorably with the
results of Chang and Anthes for a hurricane
translating at 11 ms-!. The topographic restraint
of the velocity field for stations located in
the Hudson Canyon is described.

Patchen, R. C., B. B. Parker and E, E. Long, 1976.
Analysis of current meter observations in
the New York Bight apex August 1973-June 1974.
ERL 368-MESA 5, 08/73-06/74. Environmental
Res. Lab., Boulder, CO., 24 pp.

+ A comprehensive field program in the apex region
was devised and carried out to establish the signifi-
cant temporal and spatial scales and water dynamics.
Data from 13 stations and 2 transects during 1973 and
1974 were studied along the outer apex boundaries.
Results show a frictional bottom boundary layer 7 m
above the bottom and the impacts of the principal
lunar semidiurnal (m2) and Lunisolar diurnal (ki)
constituents on circulation. Statistical analysis
shows a fall seasonal clockwise circulation with a
30% counterclockwise deviation occurring. For the
Spring season, the development of stratification and
depth of thermocline and wind driven fluxes appear
to determine the mean westward geostrophic current.
Data is on file at NODC.


The physical oceanography of this area (the NEMP area) probably is as
well studied and understood as any other coastal marine area in the world,
as the number of entries in the bibliography of this summary attests. How-
ever, much of the data or information contained in these documents is often
not readily available to or understood by non-oceanographers, especially
those who need insights to plan research and monitoring programs or have to
draw conclusions about cause and effect of pollution and are required to
make management decisions on such topics as the siting of waste dumps.

In an attempt to make this information base more available and useful
to researchers and managers concerned about resource health and ocean
dumping impacts, a team of oceanographers was asked to work together to
summarize what is known about the physical oceanographic processes of the
marine waters off the northeastern United States, with special emphasis on
those processes that influence the distribution of pollutants. This summary
report is the result of this effort.

The organization of this summary basically treats relevant features
and processes wherever they occur in the area of interest. Accordingly,
chapters are devoted to estuarine effluent plumes, upwelling, Gulf Stream
rings and meanders, fronts, density stratification, the cold pool, bottom
currents and sediment transport, and dispersion of dumped pollutants.
Following these chapters is one dealing with models of various processes.
The information on models is consolidated in one chapter rather than
scattered through the preceding chapters, in order to reduce the number
of citations resulting from the multiplicity of applications of many of
the models. The final chapter is.a geographic summary composed of charts,

locating the sites of the various relevant features and processes in the


Hopkins, T. S. 1982. On the sea-level forcing
of the Mid-Atlantic Bight. J. Geophys.
Res. 83(C3):1997-2006.

The Mid-Atlantic Bight circulation is dis-
cussed with particular comment directed toward
the role of the parabathic pressure gradient.

A distinction is made between external and local
sea level forcing. External forcing consists of
an oceanic boundary condition on the sea level
gradient. The shelf response to this is geo-
strophic: the diabathic component drives the
parabathic flow, and the parabathic component
drives diabathic flow. The latter, together
with the bottom stress generated by the former
and the physical dimensions of the shelf, deter-
mine the degree of convergence or divergence
within the shelf volume, which, in turn, deter-
mines the sea level dependence required to
satisfy continuity over the shelf. Local
forcing due to the wind stress, the internal
field of mass, and the total bottom stress, in
conjunction with local bathymetry, determines
the extent of local convergence or divergence,
and as a consequence, generates additional sea
level distortion. Conceptually, local and
external forcing can be considered as. independent
although they are, in fact, coupled through
bottom stress and internal field of mass
adjustment.

Hopkins, T. and N. Garfield. 1977, Physical
oceanography. Chapter 4. In: Sunmary
of Environmental Information - Continental
Shelf-Bay of Fundy to Cape Hatteras (1977).
U.S. Dept. of Interior, Bur. of Land
Management.

Hopkins, T. S. and N.Garfield.
of Maine Intermediate Water.
37(1):103-139.

The thermohaline dynamics of the Gulf of
Maine are analyzed from the two year, eight cruise,
data set of Colton, Marak, Nickerson, and
Stoddard (1968). Six water masses are described:
the Maine Surface Water, Maine Intermediate
Water, and the Maine Bottom Water as interior
water masses; and the Scotian Shelf Water, the
Slope Water, and the Georges Bank Water as
exterior water masses. Particular attention is
given to the formation and disposition of the
Maine Intermediate Water. Salt balance, T-S
volume, and T-S drifé analyses are used to
provide transport and mixing estimates for the
year 1966. The Slope Water entered at depth
‘through the Northeast Channel at a rate of
2600 km3/yr; while the Scotian Shelf Water
entered the surface and intermediate layers,
mostly during winter intrusions, at a rate of
5200 km3/yr. The surface and intermediate
layers exported a total of 7900 km3/yr in a
3:5 ratio, respectively. The Maine Intermediate
Water tends to collect over the Wilkinson Basin
during the stratified season, to exit via the
Great South Channel during early spring, and
to exit via the Northeast Channel during spring
and summer. Comparisons are made between the
estimated winter heat Toss of 280 Ly/d and the
observed heat losses of 230 Ly/d (surface layer)
and 360 Ly/d (surface and intermediate layers).
A limit for the Scotian Shelf Water contribution
is about -70 Ly/d. It is concluded that the
Maine Intermediate Water is produced locally
and that it is exported in significant quantities.

1979, .Guif
J. Mar. Res.

135

Hopkins, T. S. and N. Garfield, III. 1981.
Physical origins of Georges Bank Water.
J. Mar. Res. 39(3):465-500.

The seasonal behavior of the Georges Bank
Water mass is described from the context of
the historic National Oceanographic Data Center
file (1910-1978). The Georges Bank Water is
defined as the water type most commonly found in
the top 40 m of water within the 65 m isobath.
Plots of its distribution show it unique within
the Georges Bank/Gulf of Maine region. The
uniqueness is more a result of isolation and
low volune replenishment than of vertical
mixing of advective inputs from adjacent strati-
fied waters. Large scale renewal by isopycnal
intrusions of Wilkinson Basin Water is only
observed during late fall-early winter. These
conclusions are based on an analysis of
horizontal salinity gradients, on salt budget
calculations, and by comparisons with T-S
cycling in adjacent water masses. Horizontal
salinity gradients are typically <0.2 °/oo per
}00 km across the Bank and <0.1 0/00 per 100 km
along the Bank, and do not reflect a mean input
of fresher Scotian Shelf Water nor of saltier
upper Slope Water. Evaporative heat flux is a
minimum in late spring 50 Ly/day and a maxi-
mum in‘early fall ~400 Ly/day. The Georges
Bank Water has a salinity maximum of ~32.9 9/00
‘in early March and a minimum of ~32.1 °/oo in
early August, making the freshening cycle
shorter ts months) than the salting cycle. The
historic mean salinity is 32.5 0/00. Some
aspects of the circulation are analyzed. An
explanation for the observed jet flow along
the northern flank is given from a geostrophic
balance with tidal pressure force. The jet is
centered over the 50 m isobath with amplitudes
20 cm/sec. Local convergences and divergences
are created by veering of the surface Ekman
transports about the perimeter of the Bank (<60
Steady sea level response to these transport
discrepancies appears to be more effectively
maintained on an integrated Bank-wide scale
rather than locally. A sea-level high pressure
over the Bank appears to be maintained under
prevailing southwesterly winds. Its existence
requires local satisfaction of continuity in
the perimeter barotropic and tidally rectified
flows and necessitates a lack of closure in the
anticyclone circulation about the high pressure.
The completeness of the anticyclonic gyre is _
inhibited further by the lack of deep baroclinic
ajustment.

Hotchkiss, F. $. and C. bunsch. 1982.
Internal waves in Hudson Canyon with geo-
logical implications. Deep-Sea Res. 29
(4A) :415-442.

Data from an array of instruments in Hudson
Submarine Canyon for 15 weeks are qualitatively
consistent with theoretical and laboratory re-
sults concerning the concentration of internal
wave energy by canyon topographies. Internal
wave energy was intensified at the head and
near the floor of the canyon, with phase lags
Suggestive of propagation of internal waves up
the canyon from the deep sea. Significant
diurnal and semidiurnal internal tides were pre-
sent, indicating their generation at the topo-
graphic relief around the canyon, Internal wave
energy is apparently dissipated by mixing at the
head of the canyon. A major storm during the
experiment induced strong currents in the can-
yon. These currents are probably more important
‘than internal waves as carriers of sediment ex-
cept in the very head of the canyon.


Limeburner, R. 1979. Hydrography and circulation
about Nantucket Shoals. N.S. Thesis, Massa-
chusetts Institute of Technology, 113 pp.

Limeburner, R. and R. C. Beardsley. 1979.
Hydrographic station data obtained in the
vicinity of Nantucket Shoals, May, July,
and Septenber 1978. Tech. Rep. WHOI
79-30, 88 pp.

Limeburner, J. A., J. Vermersch and R. Beardsley.
1978. Hydrographic station data obtained in
the vicinity of Georges Bank, May and August,
1976. WHOI Tech. Rept. 78-82. 116 p.

Loder, John W. 1980. Topographic rectification
of tidal currents on the sides of Georges
Bank. J. Phys. Oc. 10(9):1399-1416.

The rectification of Mp tidal currents on
the sloping sides of Georges Bank is predicted
to make an important year-round contribution
to its observed mean clockwise circulation. A
rectification mechanism involving continuity
and Coriolis effects, but regulated by bottom
friction ((Huthnance, 1973), is operative.
Huthnance's (1973) depth-averaged theory for
the along-isobath mean Eulerian current associ-
ated with this mechanism and with a second,
purely frictional, mechanism is extended to
include mean current-tidal current interaction,
spatial ly-varyina bottom friction and rotary
tidal currents. The ratio of cross-isobath
tidal excursion Le to topographic length scale L
is found to be an important nondimensional
parameter in determining the degree of non-
linearity of the Coriolis mechanism. A sig-
nificant Stokes velocity is associated with
both receification processes, so that, for the
Coriolis mechanism, the mean Lagrangian
current is only about two-thirds of the mean
Eulerian current.

On the sides of Georges Bank. Le and 1

are of the same order, and the rectification
is sufficiently nonlinear that interaction of
the mean current with the tidal current is
important. The mean Eulerian and Lagrangian
currents, and the cross-isobath mean sea
surface slopes, are predicted for half-sinusoid
representations of bottom topography on the
northwestern, northern and open ocean sides
of the Bank. The mean flow is clockwise and
concentrated over the edge of the Bank, but
smeared out onto the top of the Bank by the
mean current-tidal current interaction. The
predicted current speeds, which are areatest
on the northwestern and northern sides, are
of the same order as those observed.

Luyten, J. 1977. Scales of motion in the deep
Gulf Stream and across the continental
rise. J. Mar. Res. 35(1):49-74.

+ An array of 15 moored current meters was
deployed across the continental rise near

70°W in the western North Atlantic. Data is

an examination of the space-time structure of
the low frequency fluctuation field in the
deep water near the Gulf Stream. Data provides
the first synoptic views of spatial structure
of the large amplitude fluctuation character-
istics. This report addresses a few of the
many aspects and implications of these observa-
tions, focusing upon the broader inferences

as to the scale and chara ter of this flow
regime and its possible dynamics.

Luyten, F. R. and A.R. Robinson, 1974.
Transient Gulf Stream meandering. Part II.
Analysis via a quasi-geostrophic time-
dependent model. J. Phys. Oceanogr.

4(2) :256-269.

Simultaneous path and bottom velocity
measurements made during the Transient
Meander Experiment, reported in Part I, are
analyzed in terms of a quasi-geostrophic thin
jet mode! of the meandering Gulf Stream. The
theory gives an explicit representation of
the velocity field which may be used to decom-
pose the observed velocities, This representa-
tion is shown to be consistent with the observa-
tions. The dynamics of this model provides
an equation of the path of the Stream, a cross-
sectional average of the vorticity equation. A
linearized form of this equation is used to
examine the relations between the space and
time scales of the variability. The historical
data on the space and time scales of the mean-
dering are shown to be consistent with those
implicit in the linearized form of the path
equation. The contributions to the local vorti-
city balance are estimated from the observations
reported in Part I. The data, although com-
plicated by observational errors, suggest a
balance between the local rate of change of
vorticity and the advection of vorticity. The
contributions from vortex stretching due to
variable topography appear to be unimportant
for the scales of the meandering. The local
dynamics appears to be fully time-dependent.

Magnell, B. A., S. L. Spiegel, R. I. Scarlet, and
J.B. Andrews. 1980. The relationship of
tidal and low-frequency currents on the north
slope of Georges Bank. J. Phys. Oceanogr.
10(8) 1200-1212.

Measured currents at the steeply sloping north
edge of Georges Bank show an unusually strong cor-
relation between tidal and lower frequency com-
ponents. The dominant current constituents are
the rotary semidiurnal tides (amplitude ~ 30 cm s
ellipticity 0.6) and the mean isobath-parallel
flow to the northeast (ranging from zero to 40
cm s-l). At the middle water depth in the period
range of 3-5 days, the along-isgbath Tow frequency
component is highly coherent (y@>0.8) with the
amplitude of the semidiurnal tidal current. The
fact that variation of the tidal current ampli-
tude occurs on time scales appropriate to wind-
driven events suggests that the tidal structure
must be significantly baroclinic, and this is
supported by hydrographic data. The evidence
thus suggests a local nonlinear interaction
between tidal and low-frequency currents, with
both the steep bottom topography and the density
structure being important factors.

-1

143


Newton, C. W. 1978, Fronts and wave disturbances
in Gulf Stream and atmospheric jet stream. J.
Geophys. Res.

Similarities in their basic features, including
spatial variations of frontal structure along the
current, suggest that Gulf Stream meanders are
dynamically analogous to atmospheric jet stream
waves, with descending motions upstream and ascending
motions downstream from a Wave trough. In a sym-
metrical wave with uniform speed along the current
it is shown that confluence, together with the
distribution of vertical motions, accounts for the
greater baroclinity in the frontal zone at troughs
than at crests, a necessary feature of such a wave.
Gross features of the three-dimensional motions
are discussed for an eddy in the process of cutting
off to form a Gulf Stream ring. Prior to its
detachment from the slope water mass, deduced sinking
motions exceed, by 2 orders of maani tude, the
vertical motions in ring eddies that have become
isolated. The large downward volume flux during
the formative stage is associated with the asym-
metrical structure (more water pouring into a cold
tongue on its west side than leaves it on its east
side) and with the vertical distribution of volume
transport (greater inflow than can be accommodated
by horizontal expansion in the upper layers).

The inflation time for a Gulf Stream ring is about
a month, much shorter than the decay time.

Noble, M. and 8. Butman. 1979. Low frequency wind
induced sea-level oscillations along the East
Coast of North America.

Atmospherically adjusted coastal sea level observa-
tions (ASL) and wind measurements at stations along
the east coast of North Anerica from Cape Hatteras,
North Carolina, to Eddy Point, Nova Scotia, for a
6-month winter period were used to study the spatial
structure of ASL and wind stress on the continental
shelf and to determine the low-frequency response
of ASL to wind forcing. ASL and wind stress were
coherent over distances of 1300 km for motions with
periods between 60 and 600 hours. Northward move-
ment of storm systems and the associated ASL response
was observed for stations north of Cape May, New
Jersey. South of Cape May the phase of ASL suggested
southward movement of pressure disturbances.
Longshore wind accounted for 55% of ASL eneray and
Ted ASL by 8-12 hours. Cross-shore winds were
generally not coherent with ASL. In the Middle
Atlantic Bight (MAB), sea level response was 17 om
for a 1 dyn cm- longshore wind and symmetric in
the longshore wind stress directions. In contrast,
from Nantucket north, sea level response to long-
shore wind stress was weaker (9 cm for a 1 dyn cm”
wind to the northeast). The response for wind to
the northeast was twice as large as the response for
wind stress toward the southwest. If coastal winds
were representative of winds over the shelf, the
observations imply that the wind-driven Tongshelf
geostrophic currents were larger for unit wind
stress in the MAB than in the Georges Bank-Scotian
Shelf region. The regional change in ASL response
may be due to the large semidiurnal tidal currents
which occur in the Georges Bank region or to the
rough topography on the Scotian Shelf, which
effectively increases bottom friction. The region-
al change in ASL response suggests a divergence in
longshore flow and an onshore flow on the shelf
south of Nantucket for winds to the southwest. A
low-frequency longshelf ASL slope was observed
in the MAB that was incoherent with longshelf
wind stress.

J. Geophys. Res. 34(6):3227.

149

Norcross, J. J. 1960. Investigations of
inner continental shelf waters off Tower
Chesapeake Bay, Part I - General intro-
duction and hydrography. Chesapeake Sci.
1:155-167.

* This paper serves as an introduction to a
proposed series describing the results of a
series of monthly exploratory cruises into the
neritic waters of the Atlantic Ocean adjacent to
lower Chesapeake Bay in 1959. Twenty-two off-
shore stations in addition to three stations

jn Chesapeake Bay were sampled monthly. Routine
hydrographic data were taken at each station.
Data analyses show that from December through
March the water columm was essentially homogen-
ous with respect to temperature. Vernal warming
began in April and thermal stratification
progressed through May. The distribution of
salinities was generally coasta? in character
with isohatines parallel to the coastline.

O'Connor, D. J. and J. L. Mancini. 1979. The
carbon-oxygen distribution in New York Bight
Phase I - Steady State. MESA-New York Bight
Project Report. NOAA Office of Marine Pollution
Assessment, Biology Bldg., SUNY, Stony Brook, NY

O'Connor, DO. J., J. L. Mancini and J. R, Guerriero.
1981. Evaluation of factors influencing
the temporal variation of dissolved oxygen
‘in the New York Bight - Phase II. Report
from Manhattan College, Environmental
Engineering and Science, Bronx, NY 10471.
Tp.

The purpose of this project is to evaluate
the mechanism influencing dissolved oxygen
levels in the New York Bight and to evaluate
potential engineering solutions, such as nutrient
control, for existing water quality problems.

The study employed existing data on Bight
water quality and a nonlinear water quality
mode? which considers oxygen-carbon-and nitrogen
distributions to evaluate alternative water
quality control options.

O'Connor, T. P., A. Okubo, M. A. Champ, and P, K. Park.
1981. Deep ocean dumping of sewage sludge.
Presentation to Ocean Pollution ‘81 Conference,
19-23 Oct. 1981, Halifax, Nova Scotia.


Coastal Active Band

Fronts develop because of estuarine effluent plumes, wind-driven
upwelling,or mixing in a nearshore band throughout the NEMP area of interest.
Their existence is highly variable in space and time and frequently depends
upon weather conditions. A perusal of infrared imagery from GOES and polar
orbiter satellites provides an estimate of the average width of this band
of frontal features to be about 20 km. In spite of the relatively small
scale of features in this band, they may have considerable influence on the
distribution of water-borne pollutants, because the band receives a signifi-
cant portion of the regional inputs of pollutants from estuarine effluents,

outfall discharges, and dumping.

DENSITY STRATIFICATION

The seasonal development of a surface mixed layer of low density water
and underlying pycnocline influences the dispersion of pollutant materials
introduced into the surface waters by dumping or other means. Those pollu-
tants which are dissolved or suspended will remain in the mixed layer above
the pycnocline, which forms a virtual barrier to vertical mixing. Pollutant
components which are slightly more dense than sea water in the mixed layer
sink slowly to the pycnocline then accumulate there (Orr, et al., 1680)
because of the sharp increase in water density encountered. As a consequence
of these characteristics, the water column involved in the dispersion of
dissolved or suspended pollutants is considerably shallower in the late
spring and summer when stratification occurs, than in the winter when the

water column is vertically isothermal in the upper 100-200 m.

42



iz |

casteoat
: wn

Zo Nova
P) scotia

8 ane
G2 HUDSON-RARITAN ESTUARY
SEWAGE DUMPSITE +

BUZZARDS BAY ° Bn
P 6 aad e °
ne “ pwo logttoxig  FRARRAGANSETT Bay cee °.
. _/ MATERIAL” OUMPSITE . . °° °
. KM ° e 2
. 3, eg ® oy. "ELYDONIA CANYON
72° a) °

OCEANOGRAPHER CANYON
OIL DRILLING LEASE AREA

PHILADELPHIA DUMPSITE

La2e

L 40°

L3ge

[36°

Figure 1.

KM
a7
abe ° 100 200
e..
HATTERAS ~
T T T T T T
76° 74° 72° 7o° 68° 66°

Northeast Monitoring Program area of interest, with major ecosystems
indicated. (From Annual NEMP Report on the Health of the Northeast
Coastal Waters of the United States, 1980. NOAA Tech. Memo.
NMFS-F/NEC-10).



surface mixed layer cuts across the front (Bowman and Wunderlich, 1977).
The vertical temperature and salinity structure within the front can develop
complex patterns because of inter-leaving of shelf and slope waters in the
form of offshore extrusions of "cold pool" water at mid-depth, intrusions
of slope water onto the shelf along the bottom and exchanges of surface
waters. Gordon and Aikman (1981) hypothesized that considerable transfer
of salt occurs from slope water to shelf water across this front during
the summer stratified season. During this period the horizontal density
gradient is minimal across the front facilitating the transfer of about
half the salt required annually to balance fresh water inflow.

Examination of sea surface temperature patterns has shown that the
front exhibits large wavelike motions of 100 km or more, propagating at
speeds of about 5 cm-sec-! (Gunn, 1977; Halliwell, 1978). Robinson, et al.
(1974) found meanders along the front on scales of tens of kilometers with

displacement speeds of 5 to 20 cm-secTM!,

Such variations in the frontal
position have been attributed to a dynamic response to atmospheric forcing
(Stommel and Leetma, 1972; Csanady, 1973; Flagg and Beardsley, 1978), Gulf
Stream meandering (Wright, 1976), to the passage of warm-core rings through
the slope water (Beardsley and Flagg, 1976; Celone and Chamberlin, 1980)
and because of destabilization of the front resulting from river discharge
into the shelf water (Ketchum and Keen, 1955; Ketchum and Corwin, 1964).
Wind stress may be another cause of the offshore movement of the
shelf-slope front due to Ekman transport (Boicourt and Hacker, 1976;
Beardsley and Flagg, 1976) or interference with the normal momentum balance

of the front in a direction parallel to the front, thus causing geostrophic

adjustment normal to the front (Csanady, 1978). Warm core Gulf

36



Butman, B., R. C. Beardsley, and M. A. Noble.
1982. Long-term current observations on
the southern flank of Georges Bank. £0S
63(3):92-93. Abstracts for AGU/ASLO
Joint meeting in San Antonio, TX.

Feb. 16-19, 1982.

Nearly continuous current measurements at
45 and 75 m were made from May 1975 to March
1979 at 40°51'N, 67°24'W on the southern flank
of Georges Bank in water 85 m deep. The mean flow
at 45 and 75 mwas southwestward at approximately
8.6 and 3.5 cm/s respectively. At 45m, an
average seasonal change of approximately 6 cm/s
was observed in the monthly mean flow; maximum
southwestward flow was in early September and
minimum flow in early March. At 75 m, there
was no significant seasonal change in the
monthly mean flow. Hydrographic sections
suggest that much of the seasonal change in
the flow at 45 mwas caused by a cross-bank
density gradient established by summer heating.
Loder (Jour. Phys. Oceanog., 1980, p. 1399)
has suggested that part of the mean along-bank
flow may be driven by tidal rectification. His
theory predicts that the low-frequency along-bank
flow is proportional to the squared amplitude
of the cross-isobath tidal current in deep
water, On Georges Bank, the squared amplitude
of the surface tide varies by approximately
55% at fortnightly (355 hrs) and monthly
(655 hrs) periods and thus the low-frequency
flow should exhibit a similar modulation.
However, no significant spectral peaks (greater
than 1 cm/s above background) were observed
in the along-bank flow at 45 or 75m. The Tack
of coherence at 355 and 655 hours between a
simulated tide (Mp, N2, Sp constituents) and
the along-bank flow suggests that the modulation
of the along-bank flow was less than .9 and
-6 cm/s at 45 and 75 m respectively. Thus,
assuming the predicted 55% modulation, Tess
than approximately 30% (1.1 and 1.6 cm/s at 45
and 75 m) of the observed non-seasonal flow at
this location can be attributed to tidal
rectification at 90% confidence.

Butman, B. and M. Noble. 1979. Low-frequency
wind-induced sea level oscillations along
the east coast of North America. J.
Geophys. Res. 84(C6):3227-3236.

* Report on detailed analysis of wind, tide
level, and barometric pressure data for November
1973 through April 1974 for 14 coastal stations
between Cape Hatteras, North Carolina and Eddy
Point, Nova Scotia. Atmospherically adjusted
sea level was coherent with longshore winds at
low frequencies (periods 60-600 hours) over

as much as 1300 km. Response of sea level to
winds was 8-12 hours. Cross shore correlation
was weak. Response to SW winds was twice as
great as that for NE winds.

Butman, B., M. A.-Noble, R. C. Beardsley,
J. A. Vermersch, R. A. Limeburner,
B. Magnell and R. J. Schlitz. 1980.
The mean circulation on Georges Bank as
measured by moored current meters. ICES
Report ICES C.M. 1980/C:34 Hydrography
Committee. International Council for the
Exploration of the Sea, Copenhagen.

116

Butman, 8., M. Noble and D. W. Folger. 1979.
Long-term observations of bottom current
and bottom sediment movement on the Mid-
Atlantic continental shelf. J. Geophys.
Res. 84(C3):1187-1205.

Bye, J. A. T.. 1966. The wave-drift current.
J. Mar, Res. 25(1):95-102.

* Using an irrotational wave-drift current
mode1, the author shows that wave-drift current
may contribute to surface-drift velocities.

Callaway, R. E., M. Clansy, and A. Stroud, 1974.
Computation of tides, currents and dispersal
of pollutants in the New York Bight from
Block Island to Atlantic City with large grid
size, single and two layer hydrodynamical -
numerical models. Environ. Pred. Res. Fac.
Tech. Report. No. 4-74,

Callaway, R. J., A. M. Teeter, E. W. Browne, and
F. R, Ditsworth. 1976. Preliminary analysis
of the dispersion of sewage siudge discharged
from vessels to New York Bight waters, ASLO
Spec. Symp. Vol. 2: Middle Atlantic Continen-
tal Shelf and the New York Bight. p. 199-211,
New York City sewage treatment plant wastes

discharged to the New York Bight apex average 2.6%

solids with an average solids density of 1.50 9

cm73. Bulk waste density is about 1.000 g cm},

whereas the density of surface seawater in the
sludge dumping area ranges from 1.019-1.025.

Solids concentration of the wastes in the Sludge

vessels ranged from 5 to 50g liter-!. Correlation

of extinction coefficient from a 10-cm light-path
beam-transmissometer with total suspended matter

(TSM) allowed continuous profiling of TSM, STD

and beam transmittance profiles were made either

by towing the instrument through a sludge patch or

wake or by making vertical profiles. Dilution in

the wake of a release ranged from 500-1000.

The time for TSM to reach background or equil-
ibrium values (0.5-2 mg liter-!) depends on initial
concentration. Equilibrium time was approached
exponentially for well mixed conditions in about
5.5 h. Pycnocline formation in the upper 8 m
caused a similar approach to equilibrium tine;
below that depth TSM increased slightly with time.

Settling velocities for the larger flocculated
sludge particles averaged about 0.5-Icm s~!, Values
of 0.01-0.3 cms) were obtained from plots of
the center of mass of the waste field. The remain-
der of the dispersing sludge field had velocities
of 10-3cm s-} and less.

TSM from New York Harbor can reach the permit
area, but oceanographic conditions in the apex
usually prevent this.

Relocating the permit area to other deeper
areas would cause the affected bottom area to in-
crease in proportion to the increased depth, but
concentrations of settled-out material would be
inversely proportional, if the oceanographic
environment was similar.

Campbell, J. W. and J. P. Thomas (eds.). 1981.
Chesapeake Bay plume study: Superflux
1980. NASA Conf. Publ. 2188, NOAA Conf.
Publ. 2188, NOAA/NEMP IIT 81 ABCDFG 0042.
NTIS Springfield, Virginia, 522 pp.



surface waters off Long Island or bottom waters off New Jersey. The
greatest concentrations, except in high runoff periods, were found in bottom
waters off western Long Island, assumedly due to resuspension of sediments
from the broad, shallow shelf by wave action. Concentrations measured on
eight cruises at least showed traces of the plume. During the April cruise,
during high runoff, the particulate plume extended broadly southward along
the New Jersey coast at least 70 km.

Drake (1974 and 1977) and Nelsen (1979) found average surface concen-
trations of suspended particulate matter in the plume to range from 1 to
10 mg-L7! and the edge of the plume to generally lie 5 to 10 km offshore.

Fedosh and Munday ( 1982 ) analyzed 86 cloud-free images from satellite
sensors (58 Landsat color and 28 infrared) for indications of surface con-
figuration-of the Hudson-Raritan plume. In the mouth of the estuary the
turbidity plumes were typically lobed, filled the entire entrance, and
curved southward in the alongshore drift. Those plumes which extended
farther seaward tended to be more linear in form and spread farther later-
ally. Plumes extended farthest seaward under the influence of northwesterly
winds. Thermally mapped plumes had longer frontal regions than turbidity
plumes.

They also found that 51% of the plumes extended to the dredge spoil
dumpsite (25 km) and 12% reached the sewage sludge dumpsite (35 km). None

of the 82 plumes studied reached the acid waste dumpsite (45 km).

Delaware Bay Plume
Studies of surface circulation in Delaware Bay and on the adjacent

continental shelf out to about 50 km offshore using drifters provide some

15


seasons. Summer (actually May-August) is characterized by southwesterly
winds associated with large-scale circulation of subtropical anticyclones
(highs). Winter (October-March) winds are northwesterly or westerly,
stronger, and associated more with smaller-scale circulation systems.

For the Middle Atlantic Bight, the southern part of our area of
interest, Williams, et al. (1977) attribute the northwesterly wind field
of winter to the dominance of the Icelandic Low (cyclonic), yielding a
vector mean of 7-9 knots (3.5-4.5 m-sec-!) from the WNW-NW. The summer
wind field is dominated by the Bermuda Subtropical High (anticyclonic),
characterized by SW winds of 3.5-4.5 knots (1.8-2.2 m-sec-! vector mean).

In their discussion. of estuarine and continental shelf circulation
in the Middle Atlantic Bight, Beardsley and Boicourt (1981) summarize what
is known about atmospheric forcing over the continental shelf. They point
out that synoptic scale (>2 days, >500 km) disturbances are responsible
for most of the surface wind variance over the shelf and open ocean. This
is manifested in the Middle Atlantic Bight as frequent, intense cyclones
(low pressure systems); 2.5 per month in summer, 5 per month in winter and
more intense in winter than in summer. The cyclones are produced by the
interaction between warm, moist, maritime air and cooler, drier, continental
air, and characteristically intensify as they move northeastward along the
shelf toward Georges Bank and Nova Scotia. The mean surface wind stress
is eastward-southeastward except in summer, when it is northeastward, and
the mean stress is generally stronger offshore (2 to 8 times at the shelf
edge) and veers cyclonically (up to 30°) with increasing distance offshore.

Air temperature in winter over the coastal water from Maine to Virginia

is strongly influenced by the cold, continental air masses moving over the

10



INTRODUCTION . .

CONTENTS

AVERAGE CONDITIONS . 2 2. ee ee ee

ESTUARINE EFFLUENT PLUMES . 2 2 2 2. ee ee ee ee eee

Hudson Raritan Plume ...... 2.2.2.2... .000-

Delaware River Plume 2... . ee ee ee

Chesapeake Bay Plume .... 2... ....0.2.02..004

Connecticut River Plume... ...... eee ee ee

Gulf of Maine Tributary Plumes . 2... 2... ....004

UPWELLING. . . .

Northern Georges Bank... ... 2... ee ee

Massachusetts Bay 2... . ee

Middle Atlantic Bight... 2... ee eee

WARM CORE RINGS AND GULF STREAM MEANDERS ............

Continental Shelf Interactions .............4.

Interactions

FRONTS...

with the 106 Mile Dumpsite ..........

Shelf-Slope Front... 2... ee ee

Gulf Stream Front. 2... ee ee

Central Georges Bank Front... ........2..00208

Coastal Active Band «2... ee ee

DENSITY STRATIFICATION. ©. 2... ee

Gulf of Maine. ee

Georges Bank

Middle Atlantic Bight. . 2... 2... eee ee

Slope Water

12
15
7
21
2)
22
22
24
24
26
29
32
35
35
39
40
4
42
42
43
44
44
45


Gibbs, Ronald J. 1982. Turbid horizons
at mid-depth in the Wilmington Canyon
area. Estuar, Coastal Shelf Sci.,
14:313-324,

Turbid horizons have been discovered at
depths of 20 to 40 mon top of an extension
of the ‘cold pool" over the Wilmington Can-
yon and across the continental shelf to its
south. Twelve detailed profiles of salinity
temperature and light scattering were obtained
along with water samples at various depths.
These data showed no turbid horizons in areas
over the slope where the extension of the ‘cold
pool' was missing. Particle-size distributions
showed these turbid horizons are composed of
certain larger sizes of material while clay-
size material is in all samples. The turbid
horizons were composed mainly of dinoflagel-
lates and silicoflagellates.

Gingerich, K. J. and G. F. Oerte?. 1981.
Suspended particulate matter in Chesapeake
Bay entrance and adjacent shelf waters.
P, 199-221 In: Chesapeake Bay Plume Study -
Superflux 1980. NASA Conf. Publication 2188,
J. W. Campbell and J. P. Thomas (eds.),
Scientific and Technical Information Branch,
NASA, Washington, DC, 516 pp.

The Department of Oceanography, 01d Dominion
University, participated in a 1980 NASA/NOAA
Superflux program. To support the scientific
objectives of the program, water samples were
collected and analyzed for hydrocarbons, chloro-
phyll, nutrients, and suspended solid concentra-
tions and size distributions. The program
consisted of three experimental study periods
(March, Superflux I; June, Superflux II; and
October, Superflux TIT) in 1980 to study the
plume of Chesapeake Bay under various seasonal
conditions.

This report utilized the data collected
during the Superflux II mission to describe
the distribution of several component character-
istics of suspended solids that may have
influenced the Chesapeake Bay entrance and
adjacent shelf waters.

Godshatl, Frederic A., Robert 6. Williams,
Joseph H. Bishop, Fred Everdale and
Steven W. Fehler. 1980. A climatologic
and oceanographic analysis of the Georges
Bank recion of the outer continental
shelf. NOAA/EDIS Report to the Bureau
of Land Management, USDI - Interagency
agreement AAS51-1A8-14 (Sept. 1980), 290 pp.

Gordon, A. L., and Frank Aikman III. 1981. Salinity
maximum in the pycnocline of the Middle Atlantic
Bight. Limnol. Oceanogr. 26(1):123-130.

A persistent salinity maximum is observed in the
upper part of the pycnocline in sunmer-autumn over
the outer shelf of the New York Bight, induced by a
nearly isopycnal transfer of slope water to the
outer shelf. The transfer is possible only in the
stratified seasons when isopycnals are continuous
across the shelf-slope front. Estimates of the
slope-shelf salt flux required to produce the
pycnocline S-max suggest that it may provide about
half of the salt required annually in the shelf
region to balance input of river water.

128

Gordon, A. L., A. F. Amos and R. D. Gerard. 1976.
New York Bight Water Stratification ~ October
1974, Am. Soc. Limnol, Oceanogr. Special
Symp. Vol. 2:45-57.

Thermohaline stratification of New York Bight
continental shelf water during October 1974 is
basically of the summer regime. Salinity increases
markedly with increased distance from the coast,
yet a basic vertical structure is maintained; an
upper isohaline layer; a salinity maximum at the top
of the thermocline; a salinity minimum at the base
of the thermocline; a deep isohaline layer associated
with the cold near-bottom winter residual stratum;
and (over the outer shelf) a bottom intrusion of
Telatively saline and warm slope water. Inversions
in temperature and salinity are common within the
thermocline.

The pycnocline is continuous over the shelf
and slope, though some weakening and deepening occurs
over the shelf break. Over the shelf it is mainly
supported by the thermocline and over the slope
by the halocTine. The pycnocline may not be an
effective barrier to isopycnal interchange of surface
and deep layers in view of the relative slope of
isopycnals to pycnocl ine.

In October 1974 oxygen distribution of the
continental shelf was primarily two-layered, with a
sharp division at the pycnocline. The lower cold
layer has an oxygen concentration of near 60% of
full saturation, with values near 3.6 ml/liter.
This is low; if the deeper layer is principally
a residue of the winter homogeneous condition with
initial saturated oxygen values, it would represent
oxygen consumption at a rate of 2.6 ml/liter during
the six summer months after accounting for the low
oxygen influx of slope water,

Gordon, A. L. and R. D. Gerard. 1973. Wind drift
surface currents and spread of contaminants
in shelf waters. U.S. Coast Guard Report
CG-D-5-75. U.S. Dept. Transportation Pub.,
64 pp.

From July 1972 to February 1973 a number of
experiments were carried out in the vicinity of
Ambrose Tower, designed to study the velocity field
in the upper few meters of the water column and
dependence of local environmental factors. The
experiments consisted of aerial photography of a
pattern of dyed water, free drifters, dye plumes

from anchored generators, drogues set at 1, 3 and

5 meters and floating computer cards. Also photo-
graphed were the acid-iron discolored water pattern
farther off the coast which enabled large-scale study.
The basic aim of the set of experiments is to

better understand the fate and behavior of of]
contamination.

The results of the experiments indicate the
presence of strong vertical and lateral shear with-
‘in the upper few meters of the water. The upper
few centimeters, the layer which would contain the
oil contamination, often moves at velocities quite
different from average "surface drift.” The
convergent zones detected by the dye also accumu-
late the oil and move the 072 windward at accelerated
rates, The oil and dye have been observed to be
frequently transferred to long discontinuity lines
in the velocity field, often seen running north-
south in the New York Bight.

OiT spilt on the ocean does not spread Jater-
ally in a uniform way, but responds to the basic
velocity field of the upper few meters (and may,
in turn, influence the velocity field directly).

The velocity field of the upper few meters is com
plex in its variants and does not appear to be
related to the wind in a simple manner. Significant
shearing was observed under calm wind conditions.

We believe that the wind factor for of] is larger
than the wind factor which is valid for average
surface drift and that this difference grows as
the surface heating increases.


BIBLIOGRAPHY

The following list of references includes all relevant published
items discovered by the authors of this report. It is not restricted
to items cited in the text, but all cited items are listed.

When abstracts or summaries were readily available to the editor
they were included. Summaries preceded by an asterisk were taken from
an annotated general bibliography prepared for the Northeast Monitoring

Program by the NOAA Environmental Data and Information Service.

106


Tidal and Sub-Tidal Near-Bottom Currents

Superimposed upon the weak alongshore mean currents discussed
above are currents in the tidal (6-24 hours) and sub-tidal (2 to several
days) frequencies which have been measured by many workers in the past
several years with current meters.

Tidal currents have reqular semi-diurnal (12 hour) periods and are
generally strongest near the coast. The tidal currents are generally
described as rotary, constantly varying in direction, thus describing
what are known as tidal ellipses. Beardsley et al. (1976) and Patchen
et al. (1976) noted from current meter data that tidal currents in the
Middle Atlantic Bight are related to the Mp and K, tidal components. The
tidal currents decrease in magnitude away from the coast and also decrease
with depth. Scott and Csanady (1976) noted moderately strong (20 cm: secTM!)
tidal currents 11 km south of Long Island during September 1975.

Subtidal currents are mostly barotropic (caused by changes in sea
level) and constant with depth. The sea level changes are due to meteoro-
logical forcing caused by either local winds or the propagation of a shelf
wave from some distant oceanic or meteorological event (Ou et al., 1981;
Bennett and Magnell, 1979; Scott and Csanady, 1976; Beardsley and Flagg,
1976). Beardsley and Butman (1974) proposed a conceptual model to explain
simultaneous measurements of sea level changes along the coast and current
meter measurements on the continental shelf. They proposed that offshore
winter storms dominate the shelf circulation by causing strong westward
wind stresses south of New England which drive water shoreward (north)
due to Ekman transport. This causes sea level to rise along the coast

which sets up a cross-shelf (seaward) pressure gradient force causing a

65


between graphic presentations of the various constituents within the plume.
They were able to define three separate subplumes emanating from the bay;
one each for salinity, total suspended matter, and hydrocarbons associated
with total suspended matter.

On ebb, water emerges from Chesapeake Bay and fiows south along the
coast, while shelf water from along the DelMarVa Peninsula is transported |
southward between the plume and shelf water southeast of the bay entrance
(Sarabun, 1981). South of Cape Henry, the three water types interact and
mix. During flood, the tidal currents off Virginia Beach are directed
roughly northwest which results in the scalloping of the plume edge seen
in Seasat-SAR imagery of the coast south of Cape Henry.

Upper-layer flow measurements Tend further credence to the idea that
the Middle Atlantic Bight shelf currents are ordered in a series of bands
parallel to the coast (Boicourt, 1981). The outer shelf water is moving
south in the mean, while the inner shelf is at the mercy of the winds, such
that the summer flow is typically to the north. The narrow (10-20 km)
band along the coast can be affected by estuarine circulation such that,
along the Virginia and North Carolina coasts, the flow is to the south.

The strength and spatial extent of this influence depends primarily on the
magnitude of the estuarine outflow. Evidence of banding (parallel to the
coast) for this area is seen also in satellite thermal imagery (Vukovich

and Crissman, 1981). The southward-flowing shelf waters along with admix-
tures of the Chesapeake Bay plume eventually become entrained in the Gulf
Stream off Cape Hatteras (Fisher, 1972; Ruzecki, et al., 1976) except on
occasions when strong northeast winds force these waters around Cape Hatteras

and into Raleigh Bay (Stefannson, et al., 1971).

20


Kao, T. W. 1980. continued

The surface jet exhibits anticyclonic shear in
the light water pool and cyclonic shear: across
the front. It is also shown that horizontal
diffusive effects are umimportant. Compari-
sons with known hydrographic features of the
Gulf Stream are made, showing good agreement.
especially on the major features, It is thus
seen the mean Gulf Stream dynamics can indeed
by interpreted in terms of a solution of the
Navier-Stokes and diffusion equations, with the
cross-stream circulation responsible for main-
tenance of the front. This mechanism is thus
suggested in this paper as a mechanism for the
maintenance of the Gulf Stream Dynamics.

For large values of E, it will be shown
that another type of scaling is required. That
result will be shown in a subsequent paper as
Part II of this series, and is relevant to the
study of density and current structure on the
East Coast continental shelf of North America
from Newfoundland to Chesapeake Bay, a region
subject to forcing by freshwater river discharges.

Kao, T. W. 1981. The dynamics of oceanic fronts.
Part II: Shelf water structure due to fresh
water discharge. J. Phys. Oceanogr. 11(a):
1215-1223.

In Part I of this series, a framework was

introduced for the study of oceanic frontal dynamics.

The dynamics was studied by posing an initial value
problem, starting with a near-surface discharge

of buoyant water with a prescribed density deficit
{nto an ambient stationary fluid of uniform density.
An essential aspect of the framework was the
identification of the proper length scales: an
inertial length scale Lo, q buoyancy length scale
ho and a diffusive length scale hy. In Part I,

the horizontal and vertical dimensions were scaled
by Lo and ho, respectively; and two dimensionless
parameters were formed, viz., RO = Lo/ho and

E = (hy/hg)2, It was shown in Part I that under
this scaling the normalized equations depended on

E only for RO sufficiently large. The solution

for E small, i.e., for the almost inviscid case,
was given in Part 1; and the equilibrium state

was discussed in a frame of reference in which the
front was stationary.

In this paper, we present the solution for
Jarge E. It will be shown that a universal similar-
ity (in the sense of a fully scaled set of governing
equations without any parameter) is obtained, when
the horizontal and vertical dimensions are now
scaled by Lo and hy, respectively, for a given
dimensionless depth dsd constitutes the only param-
eter of the problem and enters it through the
Jocation of the bottom. The solution for d=10
is relevant to the study of the establishment of
current and density structure of the shelf water
subject to forcing by freshwater discharge along
the coast, such as the mid-shelf region of the
east coast continental shelf of North America.

It is shown that when equilibrium is reached, a
frontal region can be identified, which propagates
steadily but slowly across the shelf. Behind the
frontal region the horizontal flow field is steady.
The nature of the force balance in the cross-shelf
and along-shelf directions is clarified.

This paper is totally self-contained and can
be read without reference to Part I.

139

kao, T. W. and R. E. Cheney. 1982. The Gulf
Stream front: A comparison between SEASAT
altimeter observations and theory, J. Geophy.
Res. 87(C1):539-454.

In a recent paper by Cheney and Marsh (1981),
SEASAT altimeter data were used to derive quantitative
information on sea surface height anomalies across
the Gulf Stream. In another recent paper by Kao
(1980), the dynamics of the Gulf Stream front was
investigated, and a similarity solution was obtained.
The mode? gives a universal shape of the sea surface
height rise and the width of that anomaly across
the Gulf Stream, In this paper we present a
quantitative comparison between the model and six
Gulf Stream altimeter profiles representing a broad
range of conditions. The remarkable closeness of
fit is mutually reinforcing to both the model and
to the role of satellite altimetry in ocean dynamics.
Comparisons of the data with the well-known
theories of Stonme? (1966) and Charney (1955)
are also made, and implications of these comparisons
are explored.

D. Lambert, 6. Rowe, and
1973. Bottom currents in
Science 180:181-183.

Keller, G. H.
N. Staresinic.
the Hudson Canyon.
April 1973.

In-place measurements of the bottom currents
in the Hudson Canyon reveal that the current regime
js characterized by a pronounced reversal of flow
up and down the canyon. Velocities are commonly
of the order of 8 to 15 centimeters per second,
reaching 27 centimeters per second on occasion in
the upper and central portion of the canyon.
Although a 2.5 day recording of currents showed
a net transport upcanyon, a combination of 66
current measurements from the submersible Alvin,
the analysis of sediment texture and organic carbon,
and the determination of the benthic fauna-nutrient
relationship indicate that over the Tong term there
is a net transport of fine material through the
canyon to the outer continental rise.

Kendall, 8. M. 1981, Remote sensing of the
Chesapeake Bay Plume salinity via microwave
radiometry. Chesapeake Bay plume study:
Superflux 1980. Campbell, J. W. and J. P.
Thomas (Eds.)._ NASA Conf. Pub). 2188, NOAA/
NEMP III 81 ABCDFGOO42, NTIS, Springfield,
Virginia. 522 pp.

Ketchum, B. H. 1976, The old and the new: New
York Bight research in perspective.
Middle Atlantic Continental Shelf and th
New York Bight. (M. Grant Gross, ed.).
ASLO Special Symposia Vol. 2.



O 50 100 150NM Ue.

Zz

Figure 3. General surface layer circulation of northwestern
Atlantic coastal and offshore waters.


Ichiye, T., M. Inove and M. Carnes. 1981.
Horizontal diffusion in ocean dumping experi-
ments. p. 131-159. In: Ocean Dumping of
Industrial Wastes. B. H. Ketchum, D, R.
Kester and P. K. Park (Eds.). Plenum Press,
New York and London.

During two experiments monitoring ocean dump-
ing operations in the Gulf of Mexico and off
Arecibo, Puerto Rico, a number of drifters were
tracked with a ship-borne radar and aerial photo-
graphs of the plumes were analyzed by use of the
results of drifter experiments in the Gulf of
Mexico. Horizontal eddy diffusivity was deter-
mined from increases of the variances of the drifter
positions with time and were calculated with
Okubo's method (1976). The variances of drifter
positions did not increase with time when the wind
speed exceeded critical values off Puerto Rico.

It was speculated that the wind rows caused the
drifter convergence during the Puerto Rico
experiments. The speculation is partially confirmed
by analyzing the aerial photos of the plumes which
show striations alona the direction of the
prevailing winds.

Ikeda, M. 1981a. Meanders and detached eddies of
a strong eastward-flowing jet using a two-
layer quasi-geostrophic model. J. Phys.
Oceanogr, 11(4): 526-540.

The process of meander growth on and eddy
detachment from an eastward flowing oceanic jet,
which is modeled after the Gulf Stream east of Cape
Hatteras, is studied using numerical solutions of
nonlinear equations. The equations express
potential vorticity conservation in a two-layer
quasi-geostrophic model with a weak planetary 6
effect. Solutions are restricted to a spatially
periodic, temporally growing case. Initially,
small-amplitude meanders are given, being super-
imposed on the jet. The solutions describe a
process in which the meanders grow increasingly
larger, the larger meanders are cut off, and cyclonic
and anticyclonic eddies are detached southward
and northward, respectively. Concurrent with the
eddy detachment, an eastward flow is restored in
the upper layer, and the lower layer develops
an eastward flow under the restored jet and two
westward flows north and south of it. A baroclinic
instability is very effective in meander growth,
while a weak @ effect is necessary for eddy de-
tachment; i.e., the meander grows large enough
for the detachment by taking potential eneray
from the basic flow, and the @ effect then cuts
off the large amplitude meanders.

This two-layer weak planetary 8 case is
contrasted with a one-layer case when meander
amplitude is much smaller, as well as a two-layer
zero 6 case when no eddy is detached in spite
of large amplitude meanders. A topographic &
effect is examined, when southward increase of
depth is introduced instead of latitudinal gradient
of the Coriolis parameter. In a weak topographic
8 case, flow patterns are very similar to those
of a weak planetary 8 case. In a strong topo-
graphic 8 case, no eddy is detached. The results
are compared with Gulf Stream meanders and
detached eddies.

137

Ikeda, M. 1981b. Instability and splitting of
mesoscale rings using a two-layer quasi
geostrophic model of an F-plane. J. Phys.
Oceanogr. 11(7):987-998.

Asymmetric instability of a circular Gaussian
ring and evolution of a ring shape in a nonlinear
case are studied using a two-layer quasi-geo-
strophic model on an f plane, Ring behavior
is classified on an F- plane with other parame-
ters fixed, where F is an internal rotational
Froude number associated with a two-layer model,
and , is a ratio of the rotation speed in the
lower layer to that in the upper layer. In the
range concerned where F < 4 and 2> 0, the mode
having an azimuthal wavenumber of 2 is the fastest
growing, followed by the mode of the wavenumber 3.
The ring is more unstable as F increases and as
a decreases, where larger F corresponds to small-
er density difference or to a larger ring size.
By numerical calculations, for which an initial”
perturbation of the wavenumber 2 is superimposed
on a ring, ring behavior is classified into
four groups from the most unstable to the most
stable case: (i) a ring that splits into two
small rings, (ii) a ring that rapidly becomes a
slender ellipse and returns to a circle, (iii)

a ring that slowly becomes an ellipse and returns
to a circle, and (iv) a ring that approaches a
circle from the beginning. For the groups (ii)
and (iii), the ring is stabilized by nonlinear
effects after the ring becomes a slender ellipse,
although the ring is unstable during an infinite-
simal_perturbation.

Two connected rings are studied using
numerical calculations. A weaker companion ring
is absorbed into a stronger major ring when the
distance between the two rings is identical to
the radius of the ring, In contrast when the
distance is doubled, the companion separates from
the major ring. The theory is applied to Gulf
Stream rings.

Ingham, M. C. 1976. Variations in the shelf
water front off the Atlantic coast between
Cape Hatteras and Georges Bank. In: J.R.
Goulet, Jr. (compiler). NOAA/NMFS MARMAP
contrib. 104. p, 17-1--17-21.

Ingham, M. C., J. J. Bisagni and D. Mizenko.
1977. The general physical oceanography
of Deepwater Dumpsite 106. In: Baseline
Rep. of Environmental Conditions in Deep-
water Dumpsite 106. NOAA Dumpsite Eval.
Rep. 77-1, U.S. Dept. of Conm. pp 29-54.

Interstate Electronics Corp. 1978. A summary
of data pertaining to two ocean disposal
sites in the Middle Atlantic Bight with
recommendations for further Studies.
Unpublished report prepared for U. S. Env.
Prot. Agency, Washington, D.C. 20460

Iselin, C. O'D. 1936. A study of the circu-
lation of the western North Atlantic.
Papers in Phys. Oceanogr. and Meteor.
4:1-101.


hydrogen sulfide odors in the surf zone of the south central coast of New
Jersey in late July and early August, indicating upwelling of the anoxic
bottom layer clear into the surf zone. Nelsen, et al. (1978) and Mayer and
Han (in press) have identified a relationship between local wind stress
and onshore flow of bottom water in the Hudson Shelf Valley (upwelling) in
the apex of New York Bight.

Upwelling conditions along the south coast of Long Island have been
found to be dependent upon local winds. Scott and Csanady (1976) found
that eastward wind stress caused offshore flow in the surface layer and
compensating onshore flow near-bottom, during summer stratified conditions
in 32 m water depth 11 km offshore. They found westward wind stress caused
flow in the reverse directions. Han and Mayer (1981), however, observed
offshore surface currents and onshore near-bottom currents during periods
of both eastward and westward wind stresses, at a point 6 km offshore in
18 m water depth. Upwelling in response to westward wind stresses there is
inconsistent with Ekman theory. They found offshore bottom layer flow
(downwelling) only in response to strong westward and northward wind stresses.

Indirect evidence of upwelling south of Long Island has been reported
by Walsh, et al. (1978) in distributions of chlorophyl1, nutrients, and
zooplankton together with some wind and current data. These data showed
episodic mixing and upwelling events associated with the passage of storms.
During stratified periods, storms caused upwelling along the coast as
evidenced by higher nutrient concentrations. During unstratified periods
storms caused increased nutrient concentrations throughout the water
column over a broader area, due to mixing of near-bottom nutrients upward.

Studies with surface and bottom drifters in Rhode Island Sound (Cook,

1966) revealed surface drift to be offshore and bottom drift onshore

25


Swift, D. J. P., J. W. Lavelle, R. A. Young and
T. L. Clarke. 1978, Near-bottom sediment
concentration and fluid velocity measurements
‘on the inner continental shelf, New York.

J. Geophys. Res. 83(12) :6052-6062.

* This paper reports a series of experiments
designed to investigate the relationship between
near-bottom fluid velocity and suspended matter

fon the inner continental shelf south of Long Island,
New York during a 27 day period of October 1976.

"If conditions are reasonably similar one might
exvect that sampling near-bottom suspended matter
concentrations with conventional survey techniques
in coastal areas which are wave and wind controlled
is unlikely to yield representative samples in any
but the most quiescent of conditions. If spatial
distribution of near bottom suspended matter are
sought at time of unusual wave or current conditions
the results from this study pose the question as

to whether a synoptic view can be gathered without
an array of in situ instrumentation."

Swift, D. J. P. and T. R. McKinney. 1974. Large
scale current lineations of the central New
Jersey shelf: Investigations by side scan
sonar. Mar, Geol, 17:79-102.

Swift, D. J. P., R, A. Young, T. L. Clark,
G. L. F. Freeland, C. £. Vincent. 1981,
Sediment dispersal in the vicinity of the
New York Bight dumpsites (abstract). Proaram
and Abstracts, Third International Ocean
Disposal Symposium, Woods Hole Oceanographic
Inst., Woods Hole, Mass., October 12-16, 1981.

Talay, T. A. and C. H. Whitlock. 1975. Mave
modeling and experimental activities in
the Baltimore Canyon region. In: Marine
Environmental Implications of Offshore
Oil and Gas Development in the Baltimore
Canyon Region of the Mid-Atlantic Coast.
Proceedings of Estuarine Research Federa-
tion Outer Continental Shelf Conference
and Workshop. Published by Estuarine
Research Federation.

Taylor, C. B. 1957. Extreme sea water temperature
and densities along the North Atlantic states
during summer 1955. J. Mar. Res. 16(1):1-7.

* — Author presents an analysis of the record high
sea water temperatures and extremely low densities
observed in harbor and coastal waters of the North
Atlantic states during the surmer of 1955.

From observations of Weather Bureau and Coast
and Geodetic Survey data collected at that time, it
was determined that hurricanes Connie and Diane
were responsible for the record low densities (or
salinities) and the high sea water temperatures were
due in large part to continued high air temperatures.

Thomann, R. V. 1980. Measures of verification.
In: Proceedings of workshop on verification
of water quality models. EPA-6009-80-016
April 1980. Environmental Research Laboratory.
Office of Research and Development, U.S.
Environmental Protection Agency, Athens,
Georgia 30605.

162

Thomann, R. V., H. J. Salas and D. J. O'Connor.
1977. Water quality. MESAN.Y. Bight
Atlas Monograph No. 27, NY Sea Grant
Institute, Albany, NY, 104 pp.

* — Water quality of the New York Bight is
measured by the following parameters: tempera~
ture, salinity, turbidity, secchi depth, dissolved
oxygen, nitrogen and phosphorus forms, silicate,
pH, heavy metals, coliform bacteria and phyto-
plankton chlorophyl1. An attempt is made to
identify and monitor recent changes in water
quality, The monograph does not address benthic
or atmospheric boundary conditions.

Data encompasses ten data sets from 1948
to present. Gaps exist from 3 to 10 years.

Thomas, J. P. 1981, Chesapeake Bay plume studies
(SUPERFLUX) relative to the biology of the
contiguous shelf, fishery research and
monitoring. In:” Oceans '81 Conference
Record, Vol. 2, IEEE Publ. No. 81CHT685-7,
pp. 1216-1221,

A study was initiated in 1980 to study the
influence of the Chesapeake Bay plume on the
continuous shelf using both in situ and remote
sensing techniques. The combined use of in situ
and remotely sensed data has enabled us to define
the area of the continental shelf that is influ-
enced by the Chesapeake Bay plume. Maters
emanating from the Bay contained biostimulants,
contaminants and other materials as well as
increased biomass and biological activity, and
a different assemblage of phytoplankton.

Remote sensing added to our ability to understand
the complex and dynamic plume and adjacent shelf
area by 1) providing synoptic and detailed informa-
tion for the surface field in which in situ
measurements were made and, 2) directing surface
ships to key areas to maximize their sampling
ability. Surface ships provided information
concerning 1) the vertical structure of the water
column and 2) variables not directly relatable

to those measured by remote sensors.

Thomas, J. P. 1981, Assessment of Superflux
relative to fisheries research and monitoring.
In: Chesapeake Bay Plume Study. Superflux
1980. Campbell, J. W. and J. P. Thomas
(Eds.) NASA Conf. Publ. 2188, NOAA/NEMP Hil
81 ABCDFGO042, 522 pp-

Thurberg, F. P. and R. 0. Goodlett. 1979. Low
dissolved oxygen concentrations and surf
clams - a laboratory study. Chap. 11. In:
Oxygen depletion and associated benthic
mortalities in the New York Bight, 1976.

R. L. Swanson and C. J. Sindermann (Eds.)
NOAA Prof, Paper No. 11, U.S. Dept. Conmerce,
Rockville, Maryland.


COLD POOL/THERMAL. STRATIFICATION

Reference Area * Description

Ou & Houghton Nantucket Shoals to 1-D model with non-uniform

(1981) Hudson Shelf Valley rates of heating and with
bathymetric features

Aikman (1981) Middle Atlantic Bight 1-D, 2 layer model of

shelf and slope density stratification

Shaw (1981) cold pool theoretical model to investi-
gate dynamics of cold pool
movement

Anderson, et al North Atlantic numerical experiments to

(1979) clarify role of stratification

and topography on transient
response to change in wind

forcing
Han & Niedrauer New York Bight mixing model used to determine
(1981) cold pool diffusion coefficients

94



Howe, M. R. 1962. Some direct measurements
of the nontidal flow on the continental
shelf between Cape Cod and Cape Hatteras.
Deep Sea Res. 9:445-455,

* Author reports measurements of drift
current velocity and hydrographic properties

on 2 cruises in July-August, and November 1961,
covering 5 cross-shelf sections between Cape
Hatteras and Nantucket Shoals. The hydrographic
data are of interest but the drift measurements
were made over 2 or 3 lunar days only, thus
representing only spot measures of the highly
variable wind-driven eneray regime.

Hsueh, Y. 1980. On the theory of deep flow in
the Hudson Shelf Valley. J. Geophys. Res.
85(C9):4913-4918,

The time averaged near-bottom current in the
New York Bight for a selected 3-day period is
idealized as a steady state response to the mean
wind at the John F. Kennedy International Airport
and the mean inflow condition across the Long
Island shelf. The idealization invoked potential
vorticity conservation in a homogeneous ocean
subject to a linear bottom friction and results
in shelf currents whose longshore components are
in general agreement with the averages of the
observed. In Hudson Shelf Valley, qualitative
agreement with the observation is achieved in the
the onshore component which is directed nearly
along the valley axis. Nearshore, within 40 km or
so of the coast, the response is, to a substantial
degree, wind driven. Nearshore upvalley mean flow
is due partly to shore-paralle! wind stresses that
are directed away from the valley and is due
partly to topographic deflection of an alongshore
current that is driven in part by the inflow con-
dition and in part by the alonashore component of
the mean wind stress. Because of the important
role of bottom friction, an alongshore current
driven by longshore winds undergoes sharper (and
more realistic) deflection across the valley than
does an alongshore current driven by the inflow
condition.

Hughes, M. M. and S. K. Cook. 1981. Water
column thermal structure across the shelf
and slope southeast of Sandy Hook, New
Jersey, in 1979. Annis. biol. Copenh.
Vol. 36:15-25.

Hunter, J. R., W. C. Boicourt and P. W. Hacker.
1977, An analysis of the winter meteoro-
logical response at sub-tidal frequencies
of the Atlantic continental shelf. Ches.
Bay Inst. Spec. Rep. 57, 21 pp.

Hydroscience. 1978a. Ocean monitoring survey at
"106" Site of Edgemoore barged wastewater,
Nay 22, 1978. Submitted to E. I. duPont
deNemours and Co., September 14, 1978.

Hydroscience, 1978. Ocean monitoring survey
at "106" Site of Edaemoore baraed wastewater
July 22, 1978. Submitted to E. I. duPont
deNemours and Co,

136

Hydroscience. 1978c. Ocean monitoring survey
at "106" Site of Grasselli barged wastewater
May 19, 1978. Submitted to E. I. duPont
deNemours and Co.

Hydroscience. 1978d. Ocean monitoring survey at
"106" Site of Grasselli barged wastewater
duly 24, 1978. Submitted to E. 1. duPont
deNemours and Co.

Hydroscience. 1978e. Report on ocean monitoring
cruise at the 106 Mile Deepwater Dumpsite.
Submitted to American Cyanimid Co.,

August 29, 1978.

Hydroscience. 1978f. Report on ocean monitoring
cruise at the 106 Mile Deepwater Dumpsite.
Submitted to American Cyanimid Co.,

October 24, 1978.

Hydroscience. 19792. Ocean monitoring survey
at "106" Site of Edgemoore barged wastewater.
Submitted to E. I. duPont deNemours and Co.

Hydroscience. 1979p. Ocean monitoring survey at
"106" Site of Grasselli barged wastewater,
October 25, 1978. Submitted to E. I. duPont
deNemours and Co.

Hydroscience. 1979c. Report on ocean monitoring
cruise at the 106 Mile Deepwater Dumpsite.
Submitted to American Cyanimid Co.
February 2, 1979.

Tanniello, J. P. 1981. Tidally-induced residual
currents in Long Istand and Block Island
sounds, Est. Coast. and Shelf Sci. 12:177-191.

The tidally-induced residual currents in the
Long Island Sound-Block Island Sound (LIS-BIS)
tidal channel are investigated using a previously-
developed analytic model. Known first order tidat
properties of LIS-BIS are matched using three
different models, chosen to isolate the effects
of the factors potentially controlling the second
order currents, either breadth, depth or eddy
viscosity variations. The residual aurrents driven
ly these first order models agree to within roughly
a factor of two, indicating that the model is not
overly sensitive to these parameters. Tidally-
induced currents on the order of observed currents
in eastern LIS and BIS are predicted. The outstand-
ing structural feature of the predicted residual
currents is a region of strong surface flow
divergence and bottom flow convergence centered
at a sharp constriction in the channel. Eulerian
and Lagrangian observations in eastern LIS and
BIS are reviewed; indirect support for the
theoretical results is found.


TABLE 2.

SUMMARY OF NUMERICAL MODELS GROUPED BY INTEREST AREAS

MIDDLE ATLANTIC REGION CIRCULATION (INCLUDING GULF OF MAINE)

Reference

Han, Hansen & Galt
(1980)

Beardsley and Haidvogel
(1981)

Beardsley and Winant
(1979)

Holland (1978)
Haidvogel and Holland

(1978)

Holland and Lin
(1975a, b)

Bush (1981)

Holland & Hirschman
(1972)

Bishop (1980)

Csanady (1976)

Sarmiento & Bryan
(1982)

Han, Hansen &
Cantillo (1979)

Ou and Beardsley (1980)

Loder (1980)

Area

New York Bight

entire Middle Atlantic Bight,
including Gulf of Maine, out
to 200 meters

Middle Atlantic Bight

idealized ocean

idealized ocean

idealized ocean

Middle Atlantic Bight shelf

North Atlantic

Middle Atlantic Bight shelf

Middle Atlantic Bight shelf

North Atlantic

New York Bight

continental shelf
south of New England

Georges Bank

87

Description

diagnostic model for
circulation

2-D wind-driven
hydrodynamic model

determined that mean cir-
culation caused by large
scale mid-ocean circulation

mesoscale eddy model
including a Gulf Stream

linear stability theory
applied to Holland (1978)

mesoscale eddy model

box model for transport

3-D circulation model with
prescribed density field

mean summer and winter
transport analytic model
(combines Csanady (1976)

and Bishop & Overland (1977))

analytic 2-D model for
winter circulation

3-D robust diagnostic
model for circulation

diagnostic model of water .
and oxygen transport

propagation of free-
topographic Rossby waves
across continental margin

mean current-tidal
current interaction


water to drift southward onto Georges Bank and into Great South Channel.
There are three water masses, identified by their temperature and salinity
characteristics, found in the Gulf and variously involved in the gyre's
motion: Maine Surface Water (MSW), Maine Intermediate Water (MIW), and
Maine Bottom Water (MBW). The first two, MSW and MIW, are low salinity
masses and the third, MBW, has a higher salinity derived from incursions
of offshore slope water. The first two are involved in annual cycles of
heating, runoff, stratification and overturn, but the third is not, and it
changes only slowly, except when intrusions of warm, saline slope water
occur or complete overturn happens in unusually cold winters.

The water on Georges Bank appears to be derived principally from
MSW and MIW with minor additions of slope water which slightly increase
its salinity. Because of strong tidal currents the water over the central,
shallow (<60 m) portion of the Bank does not experience the stratification
in spring and summer found in surrounding, deeper waters. Circulation
on the Bank also involves a seasonally variable gyre similar to that in
the Gulf, but in an anticyclonic direction (clockwise). This gyre is
well developed in the spring and summer, but during the fall and winter
its west side breaks down and a drift to the west and south occurs instead.

Shelf Water in the Middle Atlantic Bight undergoes stratification in
the spring and summer, involving the development of a surface mixed layer
of warm water underlain by a distinct thermocline. Beneath this seasonal
thermocline over much of the shelf south of Cape Cod is a layer of water
variously called the cool pool, cold cell, cold pool, or cold bottom water,
isolated from surface heating effects by the thermocline. Deepening of

the surface mixed layer and the attendant erosion of the thermocline begins


Reference
Chuang & Wang
(1981)

Kao (1980)

Olbers (1981)
Garvine (1979a, b,
1981)

Flagg & Beardsley
(1978)

Posmentier and
Houghton (1981)
Kao & Cheney (1982)

Behringer, Regier &
Stommel (1979)

FRONTS

Area
continental shelf
Gulf Stream front
oceanic fronts
Gulf Stream front

shelf-slope front
off New England

New England shelf
break front

Guif Stream front

Gulf Stream

93

Description

effect of density front at
shelf on internal tides

2-D model - forced by
buoyant material

internal wave scattering
at fronts

2-D model - integral
technique

baroclinic stability of
front over variable
topography

simple model of springtime
evolution of front

use SEASAT altimeter data
to test models (Kao (1980),
Stommel (1966, p. 109),
Charney (1955))

simple model to explore

~ thermal feedback mechanism

for Gulf Stream formation


GEOGRAPHIC SUMMARY
Summarizing the locations of the various features and processes

significant to the distribution of pollutants can best be accomplished

by a series of maps (Figs. 15-21).

98


Bumpus, D. F. 1973. A description of the circula-
tion on the continental shelf of the east
coast of the United States. Proa. Oceanogr.
6:111-157.

* Interpretation of large amounts of drift
bottle and sea-bed drifter data acquired during
the 1960's over the continental shelf of the
east coast of the United States, suggests some
approaches to elicit a better understanding of
the circulation problem in the future.

Bumpus, D. F. 1976.
oceanography of Georges Bank.
Bull. 12:119-134.

Review of the physical
ICNAF Res.

Previously published information on the
bathymetry, rotating tidal currents, temperature-
salinity distribution and general circulation
of the Gulf of Maine and Georges Bank are
discussed. New information on surface tempera-
ture fronts in relation to monthly Ekman
transport vectors is presented. Data on the
distribution of herring larvae during succes-
sive periods during the autumns of 1972, 1973,
and 1974 are used as evidence of dispersion and
advection. Feasible approaches toward develop-
ment of a circulation mode] are mentioned.

Bumpus, D. F. and L. M. Lauzier. 1965. Surface
circulation on the continental shelf off
eastern North America between Newfoundland
and Florida. Serial Atlas of the Marine
Environment Folio 7, New York, Amer.
Geophys. Soc.

Bunker, A. F. 1976. Computations of surface
energy flux and annual air-sea interaction
cycles of the North Atlantic Ocean.
Monthly Weather Rev. 104(a):1122-1140.

114

Bush, K. A. 1981. Middle Atlantic Bight
transports determined from a salinity-heat
box model using historical hydrographic and
meteorological data. M.S. thesis. Univ.
of Delaware, College of Marine Studies,
Lewes, Delaware.

A salinity-heat box model of the Middle
Atlantic Bight (MAB) has been formulated to
calculate volume transports of northern shelf
and near-surface slope waters into, and of MAB
shelf water out of, the MAB shelf region. Results
were obtained for each of two years, 1967 and
1971, using tracer mean values and uncertainties
determined from historical hydrographic and
meteorological data. The atmospheric source
term, or surface energy flux, was “calculated
from the bulk aerodynamic equations for latent
and sensible heat exchange and from the radia-
tional exchange equation using Bunker's (1975)
technique.

Transports calculated from this model are
consistent with transports determined from other
MAB studies, indicating the validity of this
approach to MAB circulation studies. Variations
in transports calculated for 1967 and 1971
reflect variations in the hydrographic and
meteorological conditions during these two years.
A sensitivity analysis for each of the two years
indicates that the model is most sensitive to
changes in MAB shelf water salinity and tempera-
ture values and to changes in northern shelf
water temperature values.

Bush, K, and S. L. Kuoferman. 1980. Wind stress
direction and the alongshore pressure
gradient in the Middle Atlantic Bight. J.
Phys. Oceanogr. 10(3):470-471.

We find that the alongshore transport in
winter calculated using a circulation mode? based
on Ekman and geostrophic dynamics (Csanady, 1976)
for a shelf region similar to the Middle Atlantic
Bight is sensitive both to the alongshore compo-
nent of the wind stress and the alongshore
pressure gradient. If the total alongshore
transport in the region remains uniform along
the shelf at -2.5 x 10°m’s"? (positive poleward)
as indicated by current meter measurements, our
calculations show that the alongshore pressure
gradient must decrease from 1 x 10-? Pa m-?

Off Montauk Point to zero south of Cape Henry,
as a consequence of the change in orientation
of shelf to wind stress.


The tidal motion is rotary with excursion ellipses of about 5 km by 10 km
so that the speed of the water remains high throughout the tidal cycle.
The tidal currents are fairly uniform with depth and, at the bottom, are
strong enough to erode and remove fine-grained sediment by suspension

and to cause bedload transport of coarser material. The direction of
sediment transport is expected to follow the mean circulation pattern.

As a result of this active transport, the surface sediments on both Georges
Bank and Nantucket Shoals are comprised of sands and gravel, since finer
grained sediments (silt and clay) are constantly winnowed away (Twichell,

et al., 1981).

Middle Atlantic Bight

Sediment transport in the Middle Atlantic Bight appears to be dominated
by strong, infrequent storm-induced events separated by periods of little
transport. Finer sediments may remain in suspension for a long enough
period of time to move shoreward in the estuarine-like gravitational circula-
tion which is apparent, at least on the inner shelf. Some of these fines
may find their way into the estuaries themselves.

Sea bed drifter studies have provided an inexpensive way to study the
net bottom currents on the continental shelf. Bumpus (1973) released
thousands of sea bed drifters, about 16% of which were returned from
region beaches or waters. These data showed a general onshore (northward)
bottom movement south of Long Island and New England at speeds of about
1-2 cm'sec-!. Over the outer shelf the bottom drift was directed westward
at about the same speeds. Off the New Jersey coast, currents converge
towards the coast between about 38.5°N and 40°N latitude. South of this
region, the drift tends towards Chesapeake Bay at about 2 cmsec"!.

Hardy et al. (1976) and Charnel1 and Hansen (1974) found similar results

61


northward to southwestward. Shonting (1969) reported similar results for
Rhode Island Sound where the surface flow above the seasonal pycnocline
was strongly isolated from the lower layer.

Nearshore current meter data collected in the apex of New York Bight
by Swift et al. (1976) showed a strong onshore transport component. A
similar onshore transport was noted by Han and Mayer (1981) on the Long
Island inner shelf near the 37 m isobath in late fall. Current records
showed both tidal and subtidal forcing, while onshore near-bottom flow
appeared to respond to the net offshore surface flow resulting in a zero
net cross-shelf flux. Only strong onshore or easterly winds produced an

offshore near-bottom component.

DISPERSION OF DUMPED POLLUTANTS

In an attempt to quantify the impact of waste materials being dumped
in the ocean, measurements of spatial and temporal concentration variations
and behavior of the waste materials are of the utmost importance. Regu-
latory agencies formulate input criteria based directly on the space-time
concentration history of the waste being discharged. However, accurate
spatial and temporal histories of waste dispersion and mixing are often
poorly understood or totally absent, because of a lack of direct field
measurements. Dispersion and mixing models may offer some alternative
to the missing field measurements by providing a framework of assumptions
and equations through which dispersion may be predicted. Models, however,
must be thoroughly tested before they can be used reliably, requiring at

Teast some direct measurements.

67


understanding of the physical system prevents us from providing a
description covering the full frequency range at any point Tet

alone the entire coastal zone."

ESTUARINE EFFLUENT PLUMES

Flow from coastal estuaries forms plumes of low salinity water which
spread over the surface of the shelf water mass. These plumes often carry
pollutants from discharges and runoff in their source estuaries, and accord-
ingly can be regarded as major point sources for a variety of pollutants.
Also, the strong salinity and temperature fronts which bound the plumes
are line convergences, which tend to concentrate floating materials, in-
cluding particulate pollutants which are buoyant or attached to buoyant
materials. The characteristic form of the plumes provides an indication of
which regions of the bottom are most likely to receive particulate materials
that slowly settle from the plume waters and which portions of the shelf
water mass are likely to experience unusually high levels of phytoplankton
productivity resulting from the higher concentrations of nutrients carried

by many of the plumes.

Hudson-Raritan Plume

Ketchum et al. (1951) provided the first extensive hydrographic survey
of the apex of the New York Bight. Their salinity and temperature data
showed that the volume of river water in the plume entering the Bight from
the Hudson River rarely exceeded 1% of the total volume of the Bight apex.
This calculation, together with knowledge of the average discharge from

the river system, led them to conclude that the residence time of river

12



Saunders, P. M. 1977. Wind stress on the
ocean over the eastern continental shelf
of North America, J. Phys. Oceanogr.
7:555-566.

Employing one million ship reports gathered
in the years 1941-72 seasonal averages of the
wind stress and its standard deviation have been
computed for the shelf region of the eastern
North American continent (out to a depth of
200 m). A drag coefficient is assumed which
increases with wind speed, from 1.0 X 10-3 at
5 ms! to 2.3 X 10-3 at 25 ms-1. Atmospheric
stratification is taken into account but its
effect is shown to be small.

In the summer season the 32-year climato-
logical wind stress is toward the northegst,
having a magnitude close to 0.25 dyn cm
throughout the entire shelf region. In the
three other seasons the stress is directed
toward the south and east being strongest in
winter (1-1.5 dyn cm-2) and weakest in fall
(0.25-0.5 dyn cm-2), In addition to the ex-
pected increase in magnitude with increasing
latitude remarkabie smal?-scale variability
occurs. An offshore increase in stress is wide-
spread and dominates the mid-Atlantic Bight; in
winter the stress there increases from 0.5 to
1.0 dyn cm-2 in going 200 km offshore. In the
Gulf of Maine and especially in the Gulf of St.
Lawrence local maxima occur; the tail of the
Grand Banks 500 km from shore shows a minimum.
Probably much of this variation is associated
with the intensity (and frequency) of cyclonic
activity rather than directly with changes in
friction at the underlying surface. Some
oceanographic consequences are conmented on
but the computations are principally intended
as a data source for further research.

Schmitz, J. £. and A. C., Vastano. 1975. Entrainment
and diffusion in a Gulf Stream cyclonic ring. J.
Phys. Oceanogy. 5:93-97.

The mixing and entrainment processes present in
a cyclonic ring are investigated by means of a parametric
model which is fitted to serial temperature data for a
North Atlantic ring. The physical mode? assumes an axial
symmetric ring in which the temperature is presumed to
governed by

at 2 13 /rkhaz } , Wola
aR a) sa cB} Lae,

where K, and Kz are the horizontal and vertical eddy diffu-
sity coefficients and J{y.1) is the (r,z) Jacobian of
the transverse stream function y and the temperature t.
Data from two cruises curing the 1967 observation of a
ring by the Woods Hole Oceanographic Institution pro-
vided estimates of the derivatives of the tempera=
ture. Regression analysis was used to determine the
coefficients for polynomial representations of ¥(r,z) _
for selected combinations of Kh and Kz, The study indi-
cates upper bounds on the orger of mgghjtudes for the
diffusivities (kp, Kz) = (10°,10) cms~” based upon
near-minimum least-squares error estimates from the re-
gression analysis. An important result is that little
differentiation exists between a purely advective the
regression analysis. An important result is that little
differentiation exists between a purely advective en-
trainment regime and those regimes including both en-
trainment and diffusion; i-e., the entrainment circu-
lation appears to be the dominant mechanism in the
temporal changes of the ring for a time scale of at
jeast two momths. The résults provide streamline
patterns for the transverse flow from the surface to
1000 m depth consistent with isotherm movement and
changes in the ring water masses.

156

Schmitz, W. J., Jr. 1974. Observations of low-
frequency current fluctuations on the
continental slope and rise near site D.

J. Mar. Res. 32(2):233-251.

* An array of 8 near bottom current moorings

were placed on’ the continental rise and slope

near site D in the area 70.5W - 71.5W, 39-40 N

in fall of 1970. Time series of current

velocity of 45 to 111 days were obtained.

Authors applied spectral and cross spectral

analyses of the series and suggest that the

phase relationships between u and v components
indicate a combination of trappina of modes
and propagation near the sTope-rise junction,
up-slope.

Schmitz, W. J. and W. B. Owens. 1979. Observed
and numerically simulated kinetic energies
for MODE eddies. J. Phys. Oceanogr.
9:1294-1297.

It is demonstrated that the outcome of an
inter-comparison between data and the vertical
distribution of eddy kinetic energy predicted
by a previously developed numerical model of
the MODE area is frequency dependent. In the
range of periods from 50 to 150 or even to
400 days (one definition of the temporal meso-
scale, the scale that the mode? was designed
to simulate), the comparison is quite good.
For periods in the range of 5 to 50 days, the
agreement is poor. For periods longer than
400 days, the comparison is indeterminate.
Earlier conclusions concerning the relation
of model results to the MODE data should be
qualified by stipulating frequency range, and
future inter-comparisons for any model in all
regions should be conscious of the desirability
of doing so across common frequencies.


Reference

Nelson, Gadd and
Clarke (1978)

Schubel & Ikubo
(1972)

Hsueh (1980)

Swift, et al
(1981)

BOTTOM CURRENTS AND SEDIMENT TRANSPORT

Area

Hudson Shelf Valley

Chesapeake Bay mouth

Hudson Valley Shelf

New York Bight

95

Description

empirical, semiquantitative
model for wind-induced flow

how sediment gets across shelf

time-averaged, near bottom
current as function of mean
wind and mean inflow along
shelf

sediment transport by tidal,
wind-driven, and wave
orbital currents treated as
a diffusion process


Chesapeake Bay Plume

Chesapeake Bay receives the discharge of several rivers including the
Susquehanna (50%), Potomac (18%) and the James (14%). Other lesser rivers
total the remaining 18% (Hargis, 1981). The annual outflow from Chesapeake
Bay to the Atlantic Ocean is estimated to be about 60 km3 (Schubel, 1972).
This constitutes over 50% of the estuarine inflow to the Middle Atlantic
Bight (Beardsley, et al., 1976). Outflow of the low salinity water from
the estuary results in a near-surface plume which extends seaward a highly
variable distance beyond the mouth of the estuary. The offshore boundary
of this low salinity, buoyant plume occurs as a sharp front.

Outflow of low-salinity water is affected by river discharge rates
and by local wind and coastal current effects, but can also be affected by
the setup of pressure gradients on the adjacent continental shelf (Wang,
1979; Wang and Elliot, 1978).

Discharge effects were greatest when Hurricane Agnes caused extremely
high discharge in the Bay during June 1972, resulting in the extension of
the low salinity plume 45 km eastward across the shelf (Schubel, et al., 1976).
Because of the storm's heavy rainfall, freshwater discharge into the Bay
increased from 2.1 x 103 m3 sec? to 48.1 x 103 m3 sec"). Salinities of
less than 30 °/oo were observed (Boicourt, 1973) along the Virginia-North
Carolina coast as far south as Oregon Inlet, North Carolina, about 130 km
south of the bay mouth (Fig. 5).

In contrast, during the second half of 1980 a severe drought affected
the northeastern United States, causing reduced discharges into the bay, with
some streamflows falling to 30% of normal. Salinities less than 30 °/oo
were observed no farther than the immediate vicinity of the bay mouth during

October 1980 (Thomas, 1981).

W7


meteorological cycle leads to stratification of these waters and the
development of a seasonal thermocline beginning in May and persisting until
October or November when cooling and storm activity destroy it (Ingham, et
al., 1977). When the seasonal thermocline is well developed, a warm
(20°-25°C) mixed layer 30-40 m thick is present. Below this mixed layer
in the seasonal thermocline temperature gradients can be as great as
0.5°C-m-1, Figure 10 shows a vertical temperature section from July 1978
from New York City southeast to the 106 Mile Dumpsite and beyond. The
near-surface mixed layer and the seasonal thermocline are shown to be

well developed in both the shelf and slope water regions. When winter
cooling and storm wind-mixing occur, the water column becomes nearly
isothermal to approximately 100-200 m depth or the top of the permanent
thermocline (Fig. 11).

Movement of the shelf-slope front into the slope water area may have
different results depending on the season. Overspreading of the area by
shelf water in the winter and spring would bring in colder and less saline
water into the surface slope water layers. This would form an inverted
thermocline (but not a pycnocline) with warmer more saline slope water
underlying colder less saline shelf water. During the summer and early
fall, however, overspreading by shelf water at the surface would have little
effect on the thermal stratification because of uniform surface heating of
both shelf and slope waters.

The second layer in the slope water, the permanent thermocline layer,
exists between the depths of approximately 200 and 600 m (13°C to 5°C)

1

where thermal gradients average about 0.02°C’mTM’. Water at these depths

is beyond the reach of local meteorological effects and remains relatively

46



Reference

Kangas & Hufford
(1974)

UPWELLING

Area

Massachusetts. Bay

91

Description

calculate upwelling- rates
from upward migration of

isotherms and by method of
Yoshida (1955)


60°W longitude during the past seven years has varied from six in 1974
to eleven in 1979 (Fitzgerald and Chamberlin,. 1981).

During . these years, variation in the number of rings simultaneously pre-
sent has ranged from eight during a period of a week or two in early May
1977 (iizenko and Chamberlin, 1979) to none during a six-week period

from March to mid April, 1978 (Celone and Chamberlin, 1980).

Continental Shelf Interactions with Rings and Meanders

Warm core rings and Gulf Stream meanders and interactions between
these features are not only a principal source of circulation and water
mass variability in the slope water region, but also apparently the
principal mechanisms for shoreward transfer of Gulf Stream water and
kinetic energy into the vicinity of the continental shelf. Three kinds
of interaction with continental shelf waters have been observed:

a. removal of shelf water by "entrainment",

b. injection of slope water and modified Gulf Stream water

onto the shelf, and

c. modification of circulation on the shelf.
Satellite infrared data provide direct information only on the first of
these influences, entrainment, because of its visibility at the sea sur-
face, but detection of entrainment is not possible when clouds block
transmission of thermal infrared from sea surface to satellite. Satellite
data are not adequate for estimates of volume transport from entrainment
because they measure only the surface area of entrained water and show
its general direction of movement, but provide no information on either

its depth or speed.

29


Vukovich, F. M. and B. W. Crissman, 1981.
Vonitoring the Chesapeake Bay using satellite
data for Superflux III. In: Chesapeake
Bay plume study: Superflux 1980. Campbell,
J.W. and J. P. Thomas (Eds.). NASA Conf.
Publ. 1980, NOAA/NEMP IIT B1ABCDFGO042.

NTIS, Springfield, VA, 5aa pp.

Walford, L. A. 1938. Effects of currents on
the distribution and survival of.eqgs and
larvae of haddock (Melanogranmus aeglefinus)
on Georges Bank. Bull. U.S. Bur. Fish.
29:1-73.

Walford, L. A. and 8. I. Wicklund. 1968.
Vonthly sea temperature structure from the
Florida Keys to Cape Cod. Serial Atlas of
the Marine Environment Folio 15, Amer.
Geogr. Soc.

Walsh, J. J., T. E. Whitledge, F. W. Barvenik,
C.D. Wirick, S. 0. Howe, W. E. Esais and
J.T. Scott. 1978. Wind events and food
chain dynamics within the New York Bight.
Limnol. Oceanogr. 23(4) 659-683.

Time series of wind, current, nutrients,
chlorophy?1, and zooplankton are used to examine
the effect of storm events on the food chain
dynamics of the New York Bight. Storms cause
dilution of phytoplankton concentration in the
vertical plane, but lead to aggregation of
chlorophyll in the horizontal field. Nutrients
are made available with onshore flow in response
to wind events favorable for upwelling. A
series of nutrient budgets suggest that storm-in-
duced mixing and upwelling of nitrate may
satisfy at least 33% of the productivity demand
of this system. Examples of the biological
response to storms are drawn from 20 cruises
during January, March, April-May, and August-
September 1974, 1975, 1976 and 1977 under mixed
and stratified conditions of the water column.
The interaction of storms and seasonal stratifi-
cation suggests predictable structure and
frequency of chlorophyl] distribution across
the shelf which may influence both the survival
strategies of herbivores and the loci of eneray
transfer to the rest of the food chain.

164

Wang, 0. P. 1979. Low frequency sea level
variability on the Middle Atlantic Bight.
J. Mar. Res. 37:683-697.

Low-frequency sea level fluctuations: on
the Mid-Atlantic Bight, from Cape Cod to Cape
Hatteras, and their relations. to wind forcing
were examined over a one-year (1975) period.

The dominant sea level fluctuations occurred at
time scales of 4 days,.and they were coherent
over the entire Bight. . On the other hand, sea
levels were not coherent between the southern
(south of Kiptopeake B.) and northern part at
shorter time. scales.

Local wind forcing was important from Cape
Cod to Mape May; most of the sea level change
was driven by the:alonashore (northeast-southwest)
wind, In addition, the east-west wind set up
a large surface slope between Nantucket and
Sandy Hook. The wind set-up may be due to the
bent coastline around Sandy Hook; the frictional
effect may also play a role.

South of Cape May, the local alongshore
wind forcing was dominant at time scales shorter
than 3.3 days (in winter). At longer time
scales, contribution from free shelf waves was
significant. A southward phase propaaation of
600 km/day was found between Cape May and Cape
Hatteras, which is consistent with the shelf
wave model. The dominance of free waves
apparently was due to the lack of coherent wind
forcing south of Cape May.

Wang, D. P. 1979. Subtidal sea level variations
in the Chesapeake Bay and relations to
atmospheric forcing. J. Phys. Oceanog.
9:564-572.

Wang, D. P. and A. J. Elliot. 1978. The effect
of meteorological forcing on the Chesapeake
Bay: The coupling between an estuarine
system and its adjacent coastal water.

In: Hydrodynamics of estuaries and fjords.
(P, 127-145). d.C.J. Nihoul (Ed.).
Elsevier, Amsterdam.

Warsh, C. £. 1975. Physical oceanography
historical data for Deepwater Dumpsite
106. P. 105-140. In: May 1974 Baseline
Investigation of Deepwater Dumpsite 106.
NOAA Dunpsite Evaluation Report 75-1.
U.S. Dept. Comm. and Environ. Protection
Agency.

Warsh, C. £, 1975. Physical oceanographic
observations at Deepwater Dumpsite 106,
May 1974. P. 141-188. In: May 1974
Baseline Investigation of Deepwater Dump-
site 106. NOAA Dumpsite Evaluation Report
75-1. U.S. Dept. Comm. and Environ.
Protection Agency.


Gordon, Robert B. 1974. Dispersion of dredge
spoil dumped in nearshore waters. Est. &
Coast. Mar. Sci. 2:349-358.

* This paper is an analysis of a series of
turbidity measurements made at the New Haven
spoil ground in the Long Island Sound.
Turbidity observations during 7 different
cruises were carried out with precise naviga-
tional control, permitting quantitative observa-
tion of the deposition. Turbidity profiles
include convective descent, final collapse of
marine silt and long term dispersion of the
cloud. Details of resuspension due to the
interaction of descending spoil with the bottom
are unresolved.

Gotthardt, G. A. and G. J. Potocsky. 1974.
Life cycle of a Gulf Stream anticyclonic
eddy observed from several oceanographic
platforms, J. Phys. Oceanogr. 4(1):131-134.

Goulet, J. R., Jr. and K. A. Hausknecht. 1977,
Physical oceanography of Deepwater Dump-
site 106, Update-July 1975. P. 55-86.

In: Baseline Rep. of Environmental
Conditions in Deepwater Dumpsite 106.
NOAA Dumpsite Eval. Rep. 77-1.

Griscom, C. 1968. An analysis of subsurface
currents and temperature at a site on the
continental shelf of the northeastern
United States. Gen. Dyn. Electr. Boat
Division Rep. No. U413-68-109.

Griscom, C. A. and W. T. Sommers. 1969. Tidal
currents and coastal drift in the vicinity
of the head of Hudson Canyon.A.I.A.A. Paper
69-411; 12 p.

Gross, M. G. 1976. Waste disposal. MESA New
York Bight Atlas Monograph 26. New York
State Sea Grant Institute, SUNY, Albany,
NY 12210, 32 p.

Gunn, J. T. 1978. Variations in the position
of the shelf water front off the Atlantic
coast between Georges Bank and Cape Romain in
1976. In: Ocean Variability in the U.S.
Fishery Conservation Zone, J. R. Goulet, Jr.
and £..D, Haynes (eds). NOAA Tech. Rep.
NMFS CIRC. 427:301-314.

Gunn, J. T. 1979. Variation in the shelf water
front position from Georges Bank to Cape
Romain in 1977. Annales Biol. Copenh.

Vol. 34:36-39.

Gunnerson, C. G. 1981. The New York Bight
ecosystem. From: Marine Environmental
Pollution, 2. Dumping and Mining by
R. A. Geyer (Ed.). Elsevier Sci. Publish-
ing Co., Amsterdam, Holland.

Haidvogel, D. B. and W. R. Holland. 1978.
The stability of ocean currents in eddy-
resolving general circulation models.

J. Phys. Oceanogr, §:393-413.

The stability of currents generated in an
oceanic eddy-resolving general circulation model
EGCM (Holland, 1978) is investigated by solving
the eigenvalue problem associated with the
finite-difference quasi-geostrophic vorticity
equations which govern the flow. In general,
both barotropically and baroclinically unstable
waves are shown to exist for instantaneous
currents found in the EGCM. Although these
simulated flows are not always quasi-steady in
the sense required by the theory and are them-
selves modified by the presence of the finite
amplitude eddies, many characteristics of the
eddy field and its interaction with the time-
mean circulation can nevertheless be deduced
by thé linear stability analysis.

In particular, these investigations show
that linear stability considerations correctly
identify regions of instability in the ocean
circulation model and accurately predict the.
low-order statistical features of the eddy
field such as wavelength, period and phase speed.
The effects of weakly unstable regions which
are masked by global diagnostic techniques can
be studied with the local stability model.

The linear stability analysis also predicts,
with some success, higher order statistics such
as the sign and structure of intra-eddy energy
fluxes that are important indicators of the
dynamics of the unstable regions.

Haight, F. J. 1942. Coastal currents along
the Atlantic coast of the U.S. U.S. Coast.
Geod. Surv. Spec. Publ. No. 230. 73 p.

Halliwell, G. R., Jr, 1978. The space-time
structure and variability of the shelf water/
slope water and Gulf Stream surface
thermal fronts and warm-core eddies off
the northeast United States. M.S. Thesis,
Univ. of Delaware, Newark, DE. 195 pp.

Halliwell, G. R. and C.N.K. Mooers. 1979.
The space-time structure and variability
of the shelf water-slope water and Gulf
Stream surface temperature fronts and
associated warm core eddies. J. Geophys.
Res. 84(C12):7707-7725.

Han, G., D. V. Hansen, and A. Cantillo. 1979.
Diagnostic model of water and oxygen transport.
Chap. 8. In: Oxygen depletion and associated
benthic mortalities in New York Bight. 1976.
R. L. Swanson and C. J. Sindermann (eds).

NOAA Prof. Pap. No. 11. U.S. Dept. Comnerce,
Rockville, Maryland. p. 165-192.


water in the Bight apex was only 6-10 days, indicating relatively rapid
dispersion of the plume. Han and Niedrauer (1981) extended Ketchum's
analysis with more recent data and obtained residence times ranging from
5.5 to 12 days with an average of 6.8 days.

More recent work by Charnell and Hansen (1974) and Bowman and Wunderlich
(1977) have shown that the Bight waters are dominated by spring season
runoff. During these high discharge periods the Hudson River plume is
generally parallel to the New Jersey coast due to a southwest deflection
caused by the Coriolis effect and shelf currents (Fig. 4). Winter mixing
due to storms can rapidly and completely mix the entire water column; re-
establishment of the river plume in the Bight takes approximately 2 days.
During periods of lesser discharge (summer), location of the plume becomes
highly variable and strongly wind-influenced. Bowman (1978) showed from
data taken in August 1976 that the set and shape of the river's plume varied
widely over a 6 day time period and were influenced by wind stress.
Mechanisms by which the plume is mixed into the surrounding shelf waters
are not well understood at this time.

Computations of the particle flux from the Hudson River plume to shelf
waters of the New York Bight, based on current meter data and water samples,
were made by Young and Hillard (ms).? Suspended matter fluxes were highest
(about 30 x 10° g-sec-l-cm-2) during periods of spring runoff as a con-
sequence of increased flow, not increased concentrations of suspended
particulate matter. At other times the quantity of particulate matter
carried by the Hudson plume appeared to be "---negligible compared with dis-
charge through other adjacent coastal sectors---."

They also found that suspended particulates in the surface plume of
the Hudson River were present in concentrations usually higher than in
* Young, Robert A. and Bruce F. Hillard, U.S. Dept. of Comm., NOAA, Atlantic

Oceanographic & Meteorological Laboratories, 4301 Rickenbacker Causeway, |

Miami, FL 33149. jbreliminapy observations of particle flux related to
the Hudson River Plume, New York Bight.

13


concentrations less than 1.4 ml/1 and Azarovitz et al. (1979) found finfish
avoidance at concentrations below 2.1 ml/1. Therefore, only smal] decreases
in concentrations below normal August values can have deleterious effects
on the marine fish and shellfish, particularly in the bottom waters off

New Jersey.

The annual cycle of bottom water dissolved oxygen in figure 12
indicates that on the shelf in early spring a limited volume of oxygen
becomes trapped below the developing pycnocline. As the season progresses
through summer this volume is continuously diminished by utilization
while strengthening stratification decreases the opportunity for replen-
ishment from the oxygenated surface layer. During this time of the year,
any condition which either increases the utilization or further decreases
the replenishment, beyond normal ranges, can lead to hypoxic conditions.

It can be seen in the lower panel of figure 12 that stratification
was about one month earlier than normal in 1976, and was stronger than
normal through May (Armstrong, 1979; Hazelworth and Cunmings, 1979).

This probably had three effects: the annual maximum concentrations in

the bottom water probably were not as high as normal and the volume of
oxygen available below the pycnocline was less; the stratified season was
lengthened so that the period when utilization exceeded replenishment

was one to two months longer than normal; and with stratification stronger
than normal for March-May, replenishment from vertical exchange would

have been reduced and concentrations would have declined more rapidly

than normal for those months. Armstrong (1979) considered the result of
these effects of stratification and estimated that, if al] other conditions

had been normal, average dissolved oxygen concentrations over the New

57


Freeland, G. L. and D. J. P. Swift.
sediments.
MESA NY Bight Project and New York Sea Grant
Institute, 93 p.

1978. Surficial

* This monograph is an overview and sunmarization
of what is currently known about surficial and
suspended sediment in the New York Bight. Data are
presented as maps showing tracklines and results of
completed work,

Freeland, G. L., D. J. P. Swift and W. L.
Stubblefield, and A. E. Cook. 1976.
Surficial sediments of the NOAA-MESA study
areas in the New York Bight. In: Spec.
Symp. 2, Middle Atlantic Continental Shelf
and the New York Bight, (M.G. Gross, ed.).
Amer. Soc. Limnol. Oceanogr. pp. 90-107.

Freeland, G. L., D. J. P. Swift and R. A. Young.
1979. Mud deposits near the N.Y. Bight
Dumpsites: Origin and Behavior. In:
Ocean Dumping and Marine Pollution, Palmer
and Gross (eds.) Dowden, Hutchinson and
Ross, Inc. 73-95.

Frey, H.R. 1978. Northeastward drift in the
northern Mid-Atiantic Bight during late
spring and summer 1976. J. Geophys. Res.
83(C1) :504-514.

* Using surface drift cards dropped from
helicopters, south of Long Island, the author
describes an anomalous northeastward surface
current persistent over the summer of 1976.

Frye, 0. and.G. Williams. 1977a. Measurements
of the dispersion of barged waste near
38°50'N latitude and 72°15'W longitude at
the "106" dumpsite. Unpubl. Man. £ G & &
Environmental Consultants, Waltham, MA.

Frye, D. and G. Williams. 1977b. Measurements
of the dispersion of barged waste near
38°33'N latitude and 74°20'W Jongitude.
Unpubl. Man. E G & G Environmental Con-
sultants, Waltham, MA.

Fuglister, F. C. 1947. Average monthly sea
surface temperatures of the western North
Atlantic Ocean. Pap. Phys. Oceanogr.
Meteorol. 10(2):25 p.

Fuglister, F, C. 1963.
Oceanogr. 1:265-283.

Gulf Stream '60. Prog.

Fuglister, F. C. 1971. Cyclonic rings formed

by the Gulf Stream 1965-66. In: Studies
in Physical Oceanography. A tribute to
Georg ust on his 80th Birthday. Gordon

and Breach, Publ.

MESA NY Bight Atlas Monograph No. 10,

126

Fuglister, F. C. and A. D. Voorhis. 1965. A new
method of tracking the Gulf Stream. Limnol.
Oceanogr., Suppl. 10:115-124.

Fuglister, F. C. and L. V. Worthington. 1951.

Some results of a multiple ship survey of
the Gulf Stream. Tellus 3:1-14.

Gadd, P. E., J. W. Lavelle, and D. J, P. Swift.
1978. Estimates of sand transport on the
New York shelf using near-bottom current
meter observations. J. Sed. Petrol.,
48:239-252.

Galt, J. A. 1980. A finite-element solution
procedure for the interpolation of current
data in complex regions. J. Phys. Oceanoar.
10:1984-1997.

A finite element solution technique is
introduced to develop current patterns subject
to ceostrophic and Ekman dynamics for an irrequ-
Jar continental shelf reaion. The interpolation
bases set of functions uses triangular topology.
Alternate boundary conditions are discussed
and related to both the mathematical nature of
the governing equation and the geophysical
constraints imposed on the flow. Examples of
the derived current patterns are shown for two
regions of the Gulf of Alaska.

Garfield, N. 1978. A box model study of the circulation
in the Middle Atlantic Bight. M.S. Thesis. Univer-
sity of Delaware, College of Marine Studies, Lewes,
Delaware.

Garrett, C. 1974.
Fundy and Gulf of Maine.
Sci. 11:549-556.

Normal modes of the Bay of
Canad. J, Earth

Garrett, C. and £. Horne. 1978. Frontal
circulation due to cabbeling and double
diffusion. J. Geophys. Res. 83(C9):
4651-4656.

Garrett, C, J. R. and R. H. Loucks. 1976.
Upwelling along the Yarmouth shore of
Nova Scotia. J. Fish. Res. Board Can.
33:116-117.


Betzer, P. R. 1978, A study of the sources,
transport, and reactions of suspended particles
in waters of the New York Bight. NOAA Tech.
Memo, MESA-23. Marine Ecosystems Analysis
Program, Boulder, Colo., 37 p.

Eighty-six samples of suspended matter
collected on five cruises to the New York Bight
have been subjected to chemica) analyses. The
results demonstrate that some of the major inputs
of particulate matter to this system can be
chemically typed and then traced. Seasonal
changes in the distribution and composition of
suspended materials are related to 1) river input,
2) diatom productivity, 3) sediment-water inter-
actions, and 4) the dumping of anthropogenic
materials.

Bigelow, H. B. 1927. Physical oceanography of
the Gulf of Maine. Bull. U.S. Bur. Fish.
40:511-1027.

Bigelow, H. B, 1933. Studies of the waters on

the continental shelf, Cape Cod to Chesapeake
Bay, I. The cycle of temperature. Papers
in Physical Oceanography and Meteorology
2(4) 11-138.

Bigelow, H. B. and M. Sears. 1935, Studies of the
waters of the continental shelf, Cape Cod to
Chesapeake Bay II: Salinity. Papers in
Phys. Oceanogr. Meteorol., 4(1):1-94.

Bisagni, J. J. 1976. Passage of anticyclonic
Guif Stream eddies through Deepwater Dumpsite
106 during 1974 and 1975. NOAA Dumpsite
Eval. Rep. 76-1, U.S. Dept. Comm., 39 p.

Bisagni, J. J. 1977. Physical oceanography of
Deepwater Dumpsite 106, February-March 1976.
In: Baseline Rep. of Environmental Conditions
jn Deepwater Dumpsite 106. NOAA Dumpsite
Eval. Rep. 77-1, U.S. Dept. Comm., 87-115.

Bisagni, J. J. 1981. Lagrangian measures of near-
surface waters at the 106-Mile Dumpsite.
NOAA Tech. Memo. OMPA-11. U.S. Dept. of
Gorm. , Washington, DC 239.

Bisagni, J. J. and G. Behie. 1980. Water mass
changes and circulation patterns in the
vicinity of the 106 Mile industrial waste
Dumpsite. NOAA Northeast Monitoring Program
Report, No, NEMP-III-80-C-0049, 35 p.

110

Bisagni, J. J. and D, R. Kester.. 1981. Physical
variability at an east coast United States off-
shore dumpsite. P, 89-107. In: Ocean
Dumping of Industrial Wastes. B. H. Ketchum,
D. R. Kester and P. K. Park (eds.). Plenum
Press, New York and London. 525 p.

Three hydrographic stations conducted during
a 1977 cruise to Deepwater Dumpsite 106 inadvert-
ently sampled an established anticyclonic Gulf
Stream ring both prior to and after it interacted
with the Gulf Stream. Continuous STD data and
discrete dissolved oxygen measurements in the

ring were analyzed using tenperature-salinity (T-S)
ard tenperature-oxygen {T-0)) diagrams. These
data showed good correlatioh with T-S and T-0,
diagrams fron Gulf Stream, Sargasso and Slope
Waters obtained during a cyclonic Gulf Stream ring
study. Apparently, a new entrainment of Gulf
Stream Water around the ring occurred within the
sampling period and was manifested by increased
Salinity and decreased levels of dissolved oxygen.
Combined satellite surveillance and at-sea
measurement of temperature, salinity and oxygen
provide an accurate method of describing this
highly dynamic and variable region in and around
Deepwater Dumpsite 106.

Biscaye, P. E. and C. R. Olsen, 1976, Suspended
particulate concentrations and compositions
‘in the New York Bight. In: Special Symposia
Vol. 2, Middle Atlantic Continental Shelf
and New York Bight. M. G. Gross (ed.).
Amer. Soc. Limnol. Oceanogr. pp. 124-137.

Biscaye, P. E., C. R. Olsen and G. Mathieu. 1978.
Suspended particulates and natural radio-
nuclides as tracers of pollutant transports
in continental shelf waters of the eastern
U.S.A. In: Chemical Pollution of the Marine
Environment - Ist Anerican-Soviet Symp.

U.S. EPA Ecol. Res. Ser. EPA-600/9-78-038,
199 pp.

Bishop, J. M. 1980, A note on the seasonal
transport on the middle Atlantic shelf. J.
Geophys. Res. 85(C9}4933-4936.

A simple analytical model is proposed that
adequately predicts both the mean summer and’ mean
winter transport along the Middle Atlantic Shelf.
The mean flow is modeled by using the steady Ekman
and geostrophic equations driven by the mean wind
stress, the mean cross-shelf density gradient,
and a variable longshore sea-surface slope. It
is shown that previous models, although consistent
with this approach, might have to be refined to
include longshore and seasonal variations in the
Jongshore sea-surface slope. Also, seasonal.
variations in mean wind stress and mean cross-shelf
density gradient are identified as key components
in the description of flow dynamics. Calculated
transports agree with the limited observations.


Bothner, M. H., C. M. Parmenter and J. D. Milliman.
1981.- Temporal and spatial variations in
suspended matter in continental shelf and
slope waters off the northeastern United
States. Est. Coast. & Shelf Sci. 13(213-234).

Seston in waters of Georges Bank originates
primarily from biological production and from re-
Suspension of bottom sediments. The concentrations
of Suspended matter observed on the central shoals
are more influenced by storms than by seasonal
changes. Winter storms produce highest concentra-
tions of non-combustible material throughout
the water column, and surmer storms appear to
increase biological production by mixing addition-
al nutrients into the photic zone. On the southeast
flank of the bank, in water depths between 80 and
200 m, the concentrations of total suspended
matter and non-combustible material show little
variation compared with the central shoals, and
storm effects are far less noticeable.

Highest concentrations (>15 mg 1”') of sus-
pended matter occur in bottom waters south of
Nantucket Island after winter storms and appear
to be primarily resuspended bottom sediment.
Resuspended sediment is also common in near-bottom
waters of the southwestern Gulf of Maine, and
occasionally near the intersection of the shelf/
slope water mass front and the bottom.

Seasonal variations were observed in the
distribution and species composition of phyto-
plankton. Coccoliths are predominant on the
central bank during the winter, but during the
spring and summer they are concentrated on the
eastern flank at deeper depths.

Bothner, M. H., E. C. Spiker, P. P. Johnson,

R. R. Rendigs and P. J. Aruscavage. 1981.
Geochemical evidence for modern sediment
accumulation on the continental shelf off
southern New England. J. Sed. Petrol. 51
(1):281-292.,

An area of fine-grained sediment approximately
170 km X 74 km in size, located in water depths
between 60 m and 150 m south of Martha's Vine-
yard, Mass., is a site of modern sediment deposi-
tion. The iC ages systematically increase with
sediment depth from about 1,300 years B.P. at
the surface to 8,000-10,000 years B.?. at the
depth of maximum core penetration. The old age
for the surface sediments probably results from
a combination of deposition of old carbon and
faunal mixing. In the finest sediments, the
sedimentation rates were approximately 130 cm/
1,000 yrs when deposition began and have decreased
to about 25 cn/1,000 yrs. The decreasing sedi-
mentation rate reflects a diminishing source of
fine sediments, which presumably came from the
Georges Bank and Nantucket Shoals area.

Inventories of excess 210°b in undisturbed
cores average 70 dpm/cm? (dis integrations per
minute per square centimeter), more than two
times higher than the flux of 210Pb from the
atmosphere and from 226Ra decay in the overly-
ing water. This additional influx of 210Pb either
must be with new fine-grained sediment material
or from solutions that are stripped of their 210Pb
by particulates in the bottom nepheloid layer.
Stable Pb concentrations in surface sediments
are about 28 ppm, as much as two times higher
than concentraions at depth.
The high accumulation rates, 210Pb inventories,
and trace-metal profiles imply that this area is
a modern sink for fine-grained sediments and for
pollutants associated with particulate matter in
the water column. To our knowledge, this is the
only site of present-day natural deposition on
the Continental Shelf off the eastern United
States, exclusive of the Gulf of Maine. Because
the net currents on the outer half of this
Continental Shelf flow from northeast to south-
west, this fine-grained deposit may receive its
sediments and possible contaminants from the
Nantucket Shoals and Georges Bank regions.

112

Bowman, M. J. 1978. Spreading and mixing of the
Hudson River effluent into the New York
Bight. Hydrodynamics of Estuaries and
Fjords. In: Nihoul, J. C. J. (ed.).
Elsevier Scientific Publishing Co.-, 373-386.

Results are presented from three Hudson River
plume sampling cruises made in the New York Bight,
in August 1976.

The data show that the set and shape of the
spreading effluent vary widely over time periods
~6 days, and are clearly influenced by local wind
stress.

Application of Takano's model of a steady
state plume spreading into a stagnant ocean sug-
gests a horizontal eddy viscosity ~108 cmésec-1,
and strong anticyclonic deflection of the plume.
This value is considered to be an overestimate,
since interfacial shear stress is neglected in
‘the model.

Nore careful measurements and calculations
are needed to separate out the effects of horizon-
tal and vertical viscosities, Coriolis force,
advection by a prevailing coastal current and
local wind stress, on plume dynamics.

Bowman, M. J. and W. E. Esais. 1981. Fronts,
stratification, and mixing in Long Island and
Block Island Sounds. J. Geophys. Res. 86:
4260-4264.

Spatial patterns of bulk stratification in Long
Island and western Block Island Sounds observed near
the fall equinox of 1978 show a strgng correlation
(= 0.79) with contours of the h/US stratification
index derived fron tidal stream and depth charts.
The index delineates stratified, transitional and
mixed regions with apparent good accuracy, with the
marginally stratified frongal zones being character-
ized by Tog,oh/U% 1.5-25%. These results and
theoretical 'onsiderations suggest that the index
may be a useful parameter in corroborating and pre-
dicting frontal boundaries in other moderately
stratified estuaries where Tocal buoyancy fluxes

are derived from fresh water sources.

Bowman, M. J., W. E. Esais and M. B. Schnitzer. 1987.
Tidal stirring and the distribution of phyto-
plankton in Long Island and Block Island Sounds.
J. Mar. Res. 39(4) :587-603.

Phytoplankton distributions in Long Island and
Block [stand Sounds measured during a 1978 fall
equinox cruise are interpreted in terms of tidal
mixing variations and water column stratification.
A stratification depth-scaled-by-Tight diagram is
used to quantify the preferred physical environ-
ments of the two major morphological groups (diatoms
and microflagellates). The success of the method
in clearly distinguishing these physical regimes
suggests its value as a useful biological growth
index in estuarine systems.


COLD POOL. © eee 49
Seasonal and Interannual Variations ........... . 57
Role of Convective and Advective Mechanisms ....... 53
Hypoxia 2 6. 54

BOTTOM CURRENTS AND SEDIMENT TRANSPORT... ........0- 60
Georges Bank . 2. 1 ee ee 60
Middle Atlantic Bight... 2... ee ee ee 61
Tidal and Sub-tidal Near Bottom Currents ........ 65

DISPERSION OF DUMPED POLLUTANTS .. 1.2... ee eee eee 67
12-Mile Sewage Site... 2... ee ee 68
Acid Dump Site 2... ee 72
Midshelf Sites 2. 2... ee eee 73
Offshelf (Deep Water) Sites... 2... . 2... ee, 74

MODELS © 6 ee ee ee 80
Diagnostic Modeling in New York Bight. ......... 82
Box Model for Middle Atlantic Bight Transport. ..... 83
Dissolved Oxygen Model . 2... 1 ee ee ee 84
Hydrodynamic Modeling of Entire Shelf. .....-.... 85
Oi] Spill-Fisheries Impact Modeling. .........-- 85
Impact of Ocean Disposal] .. 1... ... ee ee 86
Summary of Numerical Models Grouped by Interest Areas

(Table 2) 2... ee ee 87

GEOGRAPHIC SUMMARY... 1 ee ee ee ee ee 98

BIBLIOGRAPHY . 6 6 6 we ee ee ee 106

vi


MIDDLE ATLANTIC BIGHT CIRCULATION (Cont.)

Reference
Bishop & Overland
(1977)

Talay & Whitlock
(1975)

Hopkins (1982)

Hopkins & Dieterle
(ms submitted to
Con. Shelf Res.)

Area
Middle Atlantic Bight
shelf

Baltimore Canyon

Middle Atlantic Bight
shelf

New York Bight

@ Waterways Experiment Station,
Corps. of Engineers, U.S. Army
personal communication.

89

Description

analytic model for mean
summer flow using
observed density field

wave refraction modeling

discusses role of local
and external forcing
using 2-D model

externally forced
barotropic circulation
model in 2-D


(METERS )

DEPTH

106 MI
DUMP SITE

STATION NO. | eee |

16 23
304 5 6 7 8 9 10 N 12 13° 1415 2021 28(26
Pye SA DG CN GN Ga OS GG BB

100
200+
3004
400-4
500
600 4
700
800

900 +

1000 +
L

soo]

2000 L

Figure 8. Warm core ring in the vicinity of the 106-Mile Dumpsite in July 1975
as revealed by a vertical section of temperature (°C). Gradients in
the thermocline were too intense for contouring at this scale (shaded
area). Surface temperatures ranged from 22 to 25°C. From Goulet and
Hausknecht, 1977.

34


Proni, J. R., F. C. Newman, 8. L. Sellers and
D. J. Walter. 1982.
New York sludge tracking experiment STAX-1.
NOAA Tech. Memo. OMPA-15. National Oceanic
and Atmospheric Administration, Office of
Marine Pollution Assessment, Boulder,
Colorado.

Sewage sludge in the ocean has been de-
tected using a modified 200 KHz acoustic echo
sounder. The three-dimensional distribution
of suspended material and its rate of diffu-
sion have been determined after digital p:
cessing of data. Increased biological acti-
vity 18 apparently associated with the pre-
sence of sewace sludge. The detection of

internal waves in 30m of water is reported.

Proni, J. R., 0. J. Walter, and R. L. Sellers.
1982.
STAX-II Final acoustical data report. NOAA
Data Report OMPA-II. Boulder, Colorado.

High frequency acoustic systems (20 and 200
kHz) have been used successfully in the detec-
tion and tracking of sewage sludge in a dunp-
ing zone in the New York Bight Apex. Observa-
tions made with these systems indicate that
particulate distribution of a dumped arti-
ficial tracer is highly dependent on changes
associated with the vertical density structure
in the water column.

Pyle, Robert L. 1962. -Sea surface temperature
regime in the western North Atlantic
1953-1954. Folio 1 - Serial Atlas of
the Marine Environment. American Geograph-
ical Society.

Twenty six pairs of maps of. mean-monthly,
annual difference (1953-54), seasonal range,
seasonal warming and cooling, seasonal maxima
and minima. Covers Atlantic coastal area from
Bahamas to Nova Scotia.

Redfield, A.C. and L, A. Walford. 1951. A
study of the disposal of chemical waste
at sea. Nat. Res. Coun, Pub. 201, Report
of the Committee for Investigation of Waste
Disposal, 29 pp.

Redfield, A. C. 1958, The influence of the
continental shelf on the tides of the
Atlantic coast of the United States. J.
Mar. Res. 17:432-448,

* — Tidal high water intervals and mean range
at 6 tide stations on U.S. east coast from

Tybee Light, Fire Island, NY, given in the U.S.
Coast & Geodetic Survey Tide Tables Atlantic
Ocean were analyzed. Tidal behavior at the
coast was dependent on numerous topographic
factors of the continental shelf. Tidal range
at the coast is shown to be dependent on distance
from the continental slope.

15th

Reed, M., ML. Spaulding, P. C. Cornillon.
1980.
An oil spill fishery interaction model:
development and applications. Report.
on Contract E(11-1)4047, U-R.I. Oc.
Eng. Dept., South Lab, Narr. RI, 02882.

Reid, Jr., J. L. 1962.
Distribution of dissolved oxygen in the
summer thermocline. J. Mar. Res. 20(2):
138-148.

Using previously published (1937-60)
oceanographic data for various cruises during
1928-1960, the following preliminary hypothe-
sis is examined: if water in the winter mix-
ed layer remains saturated with oxygen through-
out the year, then seasonal temperature changes
require the presence of a surmer subsurface
oxyty maximum. Both Atlantic and Pacific data
are examined and appear to validate the hy-
pothesis. Photosynthesis is shown to have
little effect upon subsurface maxima of oxyty.

Richardson, P. L. 198).
Gulf Stream trajectories measured with
free-drifting buoys. J. Phys. Oc. 11(7):
999-1010.

During 1975-78, 35 free- drifting buoys
measured surface currents in the Gulf Stream
region. The buoy trajectories trace num-
erous paths of the Stream and show that the
Stream is strongly influenced by the New Eng-
Tand Seamounts. This influence is manifested
as 1) a guasi-permanent, 100 km, southeast-
ward deflection of the Stream and the frequent
occurrence of a ring meander over the sea-
mounts: 2) large-amplitude meanders beginning
at the seamounts and extending eastward: and
3) small, 20 km diameter eddies which appear
to be generated locally by individual sea-
mounts.

A chart of the mean temperature field
at a depth of 450 m agrees with several of
the patterns seen in the buoy trajectories.
West of the seamounts, the mean path of the
Gulf Stream is eastward; over the seamounts,
the path turns sharply northeastward and
the isotherms in the Stream abruptly diverge.

Riley, G. A. 1967.
Mathematical model of nutrient conditions
in coastal waters. Bull. Bingham Oceanogr.
Collect. 19:72-80.

* "A mathematical model is developed to

illustrate the distribution of nitrate and

phosphate in coastal waters. The model de-
pends on the existence of a deep water source
of nutrients at the edge of the continental
shelf and determines in relation to horizon-
tal and vertical mixing and biological rates
of regeneration and utilization. It is shown
to be as applicable to the coastal region
off southern New England with respect to
nutrient concentrations, N:P ratios, and
productivity levels.”


Csanady, G. T, 1976. Mean circulation in shallow
seas. J. Geophys. Res. 81(30):5389-5399.

The mean circulation of shallow seas arises as the
residue of chaotic first-order flow episodes created
by winds, tides, and river inflow. The average effect
of many such episodes is to generate an internal pres-
sure and shear stress distribution which may differ
significantly from a steady solution of the equations
of motion. Within the coastal boundary layer (of about
10-km width), complex average effects of variable flow
probably dominate. However, in mid-shelf regions of
the Mid-Atlantic Bight, for example, classical steady
state models adequately describe the main features of
the mean circulation. The statistical effects of
variable first-order flow even bring about some
simplifications of the theory, i.e., linear internal
and bottom friction laws and a decoupling of salt
transport from the mean circulation. The mid-shelf
circulation of the Mid-Atlantic Bight is thus found
to consist of four additive components, each driven
by offshore wind, longshore wind, longshore pressure
gradient, and density contrasts caused by freshwater
influx. The longshore pressure gradient enters the
theory as a parameter necessary for describing the
interaction of a portion of the continental shelf
with the rest of the ocean. The pressure gradient
driven flow component is responsible for some notable
circulation features such as the line of divergence
in bottom drift at about the 60-m isobath. The wind-
driven and thermohaline flow components are familiar
in character. Quantitatively, the four components
together account satisfactorily for the observed
mean shelf Circulation.

Csanady, G. T. 1978. The arrested topographic
wave. J. Phys. Oceanogr. 8:47-62.

Wind effects on surface to
» Geophys. Res. 83(C9):4633-4640,

Csanady, GT. 1978.
bottom fronts.

In nearshore regions, water of reduced density is
frequently present owing to freshwater influx or spring
heating. Under some circumstances, light nearshore
water js confined to one side of a density front,
extending from surface to bottom, and is called
‘spring thermocline’ or ‘shelf edge front.' The shape
and permanency of this front are affected by wind
stress, which may interfere with the momentum balance
in a direction parallel to the front and cause geo-
strophic adjustment motions normal to the front. A
simple geostrophic adjustment theory elucidates some
of the more important effects of wind: on such fronts.
Winds opposing the geostrophic flow above the
inclined front tend to flatten its shape and eventu-
ally destroy the front, sometimes causing the forma-
tion of a surface ‘lens’ or ‘bubble.’ Comparison
with observations from Lake Ontario and from the New
England continental shelves shows that the theory
gives a realistic first-order description of frontal
behavior.

124

Csanady, G. T. 1979.
warm core ring.
777-780.

The birth and death of a
J. Geophys. Res. 84(C2):

The birth of a warm core ring is conceptua-
lized as a catastrophic separation process governed
by the strong inertial forces within a western
boundary current. A frictionless theory based
on this postulate and assumed geostrophic balance
on completion of the separation process yields a
description of ring geometry and velocity dis-
tribution in first-order agreement with observa-
tion. In particular, maximum velocities of the
order of 1 ms-} are predicted to occur near the
perimeter, The initial decay rate of the ring is
estimated from an interface friction and entrain-
ment model (using the above maximum velocity) to
be about 0.05 day, which reduces rapidly, how-
ever, as the ring slows down, Interface friction
is found to be much more important than entrain-
ment in producing the decay.

Longshore pressure gradients

Csanady, G. T. 1980.
J. Geophs. Res. 85

caused by offshore wind.
(2):1076-1084.

Observations of currents 12 km south of the
Long Island caost show that strong offshore winds
could generate considerable Tongshore nontidal flow
well below any surface Ekman drift. A momentum
balance calculation in the longshore direction
shows a surface level gradient of order 1076 to be
the proximate cause of the longshore flow. A very
simple model of the observed phenomena is 2 slop-
ing plane beach acted upon by cross-shore wind,
varying sinusoidally in the long shore direction.
With bottom friction parameterized by a linear
jaw, a parabolic equation is found to govern
steady state flow, expressing a balance of vorticity
tendencies die to cross-isobath flow, curl of
bottom stress, and any forcing. Calculated solu-
tions for variable cross-shore wind show a trapped
pressure field on the inner shelf which controls
the transition between an essentially friction-
less momentum balance on the outer shelf to friction-
ally dominated flow at the shore. Realistic
estimates of the parameters entering the theory
suggest that the longshore gradients associated
with the trapped inner shelf field-are of the
correct order of magnitude to explain the generation
of longshore flow by a system of cross-shore winds.

Csanady, G. T, 1981. Circulation in the coastal
ocean, Part 1. Trans. Am. Geophys. Union.
Vol, 62(2). dan 13, 1981.

* This is part one of a three-part series on
circulation patterns in the earth's “coastal
oceans" - large shallow bodies of water with
Horizontal dimensions of 100 km or more such as
the continental shelves, Such bodies are
characterized by “oceanic” circulation, in the
Sense that motions in them are strongly affected
by the earth's rotation. Theoretical frameworks
are described for wind-driven transient currents,
upwellings, downwellings and coastal jets pre~
sent in these waters. Confirmation of these
models are made from observations in Lake Ontario
during the International Field Year on the

Great Lakes, 1972-73.

The author stresses the importance of under-
standing patterns of residual or longer-term
water particle displacements as a means of
predicting the distribution of temperature, sa-
linity, heavy metals and nutrients.


Reference

Reed, Spaulding and
Cornillon (1980)

Fischer (1980)

Sharp & Church (1981)

O'Connor, Okubo, Champ
and Park (1981)

Falkowski, Hopkins,
and Walsh (1980)

Cornillon, Spaulding
and Hansen (1979)

Munday, Harrison,
and MacIntyre (1970)

Miller, Bacon and
Lissauer (1975)

Smith, Slack and
Davis (1976a)

Smith, Slack and
Davis (1976b)

Tingle and Dieterle
(1977)
Flier] (1980, 1981)

Swanson (1981)

Spaulding (1981)

DISPERSION OF POLLUTANTS

Area

Georges Bank

Mid-Atlantic Continental
Shelf

off Delaware Bay

DWD-106

New York Bight

Georges Bank
Chesapeake Bay

New Jersey and
Delaware coast
Mid-Atlantic outer
continental shelf
oi] lease area
North Atlantic outer
continental shelf
oil lease area

New York Bight Apex

gyre or large eddy
circulation

12-mile, 65-mile, and
106-mile dumpsites

Georges Bank

96

Description

transport- fishery- oi]
spill model

estimated dispersion of
dissolved material

biochemical dynamics
during stratification

global model for potential
effects of sewage sludge
dumping

analyze historical data

to distinguish between
man-induced & natural causes
of oxygen depletion

fate model for subsurface
and surface 01] movement

use tidal-current table date
to predict oi] slick movement

investigate techniques for
predicting oi] spill movements

oil spill risk analysis to
determine relative impact
in oi] development

oi] spill risk analysis to
determine relative impact
in oi] development

oil trajectory forecasting

simple models of distribution
and impact of waste disposal
in gyre or large eddy

develop pros and cons on
dumping sewage sludge at sites

similar to Reed, Spaulding &
Cornillon (1980) but with
3-D hydrodynamic component


Stream rings may also cause seaward extensions of the shelf/slope front
due to the rings' currents (Morgan and Bishop, 1977). Local baroclinic
instability of the front over steep topography could be another factor
affecting its movement (Flagg and Beardsley, 1978).

Cresswell (1967) reported on the presence of detached parcels of
shelf water within the slope water, which he believed had separated from
the front by "calving", and Wright (1976) concluded that the detachment of
such parcels, along with seaward excursions of the front, may account for
most of the exchange required for salt balance of the shelf waters. The
highly variable location (Fig. 9) of the shelf-slope front from Cape
Hatteras to Georges Bank has been examined from weekly interpretations of
surface thermal patterns using satellite-derived infrared imagery beginning
jn 1973 (Ingham, 1976). Gunn (1979) compiled five-year means of these
records and found that the mean position of the surface front remains
close to the location of the 200 m isobath and variability averages about
50 km around the mean position. Hilland and Armstrong (1980) examined this
five-year compilation and described seasonal tendencies to the front's
position, finding the front to be located more offshore during the first
half of the year (maximum excursion in February to April) and more shoreward
during the latter half of the year (extreme incursions in July to September).
For the period of record for these analyses (1974-1979), the most anomalous
offshore excursion occurred in 1978 when the front generally was positioned
distinctly offshore of normal (up to 150 km off southern New England)
during spring and summer (Hilland and Armstrong, 1980). This record
excursion of the front in 1978 may have resulted from increased advection
of shelf water from the east (Chamberlin, 1978) or from a total absence of

warm core rings in the slope water (Hilland and Armstrong, 1980).

37