NOAA Technical Report ERL 452-PMEL 42 

Water Properties 

Over the Bering Sea Shelf: 

Climatology and Variations 

R.K. Reed 

May 1995 

U.S. DEPARTMENT OF COMMERCE 

National Oceanic and Atmospheric Administration 

Environmental Research Laboratories 

NOAA Technical Report ERL 452-PMEL 42 

Water Properties 

Over the Bering Sea Shelf: 

Climatology and Variations 

R.K. Reed 

Paci'fic Marine Environmental Laboratory 

Seattle, Washington 

May 1995 

U.S. Department of Commerce 

Ronald H. Brown, Secretary 

National Oceanic and Atmospheric Administration 

D. James Baker, Under Secretary for Oceans and Atmosphere/Administrator 

Environmental Research Laboratories 

Silver Spring, Maryland 

James L. Rasmussen, Director 
NOTICE 

Mention of a commercial company or product does not constitute an endorsement 

by NOAAlERL. Use of information from this publication concerning proprietary 

products or the tests of such products for publicity or advertising purposes is not 

authorized. 

Contribution No. 1652 from NOAAJPacific Marine Environmental Laboratory 

For sale by the National Technical Infonnation Service. 5285 Port Royal Road
 

Springfield. VA 22161
 

11 
CONTENTS
 

Page
 

ABSTRACT · 1
 

1. INTRODUCTION 1
 

2. DATA AND METHODS 2
 

3. CLIMATOLOGY 3
 

3.1. Surface Temperature 5
 

3.2. Bottom Temperature 5
 

3.3. Surface Salinity 5
 

3.4. Bottom Salinity 5
 

3.5. Mixed-Layer Depth 11
 

4. VARIATIONS 11
 

5. DISCUSSION AND CONCLUSIONS 13
 

6. ACKNOWLEDGMENTS 14
 

7. REFERENCES 14
 

III 

Water Properties Over the Bering Sea Shelf:
 

Climatology and Variations
 

R.K. Reed 

Abstract. This study examines climatological water properties over the southeastern Bering Sea shelf 

during 1974-90. Maps of surface and bottom temperature, surface and bottom salinity, and mixedlayer depth are derived and presented for winter, spring, summer, and fall. Surface tempemtures range 

from about -I to lODe over the year. Bottom tempemtures range from about -I to 7De but are colder 

than surface tempemtures except in winter. The patterns of bottom tempemture and Salinity indicate 

the path of inflow from Unimak Pass. Surface salinities vary from -31.2 to 32.5%0; bottom salinities 

range from -31.4 to 33.0%0. Mixed-layer depths are deepest (>50 m) in winter and fall and shoalest 

in summer «15 m). Waters inshore of 50 m are not always well mixed, in contast to findings in other 

studies. The most extreme bottom water temperatures (3DC colder than normal) occurred in 1976 as 

a result of extensive ice cover in winter. 

1. INTRODUCTION 

The continental shelf of the southeastern Bering Sea (Fig. 1) is a vast area that constitutes 

about one-third ofthe entire sea south of 6Oo

N. On the western or Russian side ofthe sea, however, 

the shelf (depths <200 m) is relatively narrow. The deep basin, to the west of the area in Fig. 1, has 

maximum depths of -4000 m; its circulation system is mainly dependent on northward inflows, 

through deep passes in the Aleutian Islands, of the westward-flowing Alaskan Stream (Favorite, 

1974; Stabeno and Reed, 1994). The shelf area in Fig. 1 is largely decoupled from the oceanic 

circulation. Instead, circulation results from an inflow of relatively warm, fresh coastal water 

through Unimak Pass, with some influence from oceanic flow on the outer shelf. The most striking 

feature about the circulation over the shelf is its very weak net speeds, which range from about 1 to 

.5 cm s-1 (Schumacher and Kinder, 1983; Coachman, 1986). This extremely weak circulation permits 

the atmosphere to have the dominant influence on shelf-water properties (Niebauer and Day, 1989). 

Water properties (temperature and salinity) over the shelf vary greatly, mainly in relation to 

season and bottom depth (Reed, 1978; Kinder and Schumacher, 1981). In winter, temperature and 

salinity are nearly homogeneous in the vertical in depths 100 m. This results from minimal 

insolation and strong winds, which vigorously stir the water column and also induce large latent and 

sensible heat fluxes. In summer, the opposite extreme occurs; winds are weak, and the water heat 

budget is dominated by absorption of solar radiation (Reed, 1978). In depths ~50 m, however, there 

is a yearlong semihomogeneous water column as a result of overlapping wind and near-bottom tidal 

stirring (Kinder and Schumacher, 1981). In depths between 50 and 100 m, except in winter, there 

is a two-layer temperature and salinity structure because the wind and tidal mixed layers do not 

overlap. Farthet offshore, water structure is essentially oceanic in all seasons. 

At present, the Fisheries Oceanography Coordinated Investigations (FOCI) program of the 

National Oceanic and Atmospheric Administration (NOAA) is actively engaged in research on 

walleye pollock and the environment in the shelf area shown in Fig. 1. As part of FOCI, a 

climatological summer circulation was derived for the shelf area (see Fig. 1). Data on water 

properties are also needed, especially for the 1970s and 1980s when most of the fisheries data were 

obtained. The present study is thus an effort to derive climatological thermohaline conditions over 

the shelf during 1974-90, and also to examine year-to-year variations from climatology. It is hoped 

that this will establish a useful baseline of environmental conditions that can aid fisheries research. 
600 N 

Bering Sea 

10 em S·1 

, 

2 ems~1 0. 0 a /'

'" n· 5 em S·1 ..•'. e.~ ..... 1../0 ./J& 

550 t A ''<1 " If tJ. .l/F ....:",./ 1'. 

} .... '-.!:!..nimak Pass 10 ems·y

1 Ci~

10ems·1 

t1 

~;:P A1eutien Is. 

1700 W 1650 1600 1550 

Figure 1. Location of the study area, showing the typical net circulation and the 50-, 

100-, and l000-m isobaths. 

2. DATA AND METHODS 

The data file used was from the National Oceanographic Data Center; it contained data from 

conductivity, temperature, depth (CfD) sensors. The data are available for 1974-90 for the eastern 

Bering Sea shelf. These data generally have better resolution or accuracy than earlier data from' 

bottle casts or bathythermographs. Hence only this cm data file was used here. 

Data from each CTD cast were examined for quality. No data were used from casts that 

appeared to have spurious values of temperature or salinity. No casts were used that did not start 

within 5 m of the sea surface or reach within 20 m of the bottom (as determined from listed bottom 

depths or estimates). A few casts were rejected as a result of implausibly large density inversions. 

Data were averaged over areas of 0.5 0 latitude by 1.00 longitude (-50 x 50 kIn). This is a 

compromise between spatial resolution and data availability. There are no data in this file for the 

month ofDecember, and data for January and November are very sparse. It was decided to produce 

seasonal distributions by averaging over the following periods: winter (February-March); spring 

(April-May); summer (July-August); and fall (October-November). Note that data from June and 

September were not used even though they are fairly abundant. Values in these months were quite 

variable and appear to reflect year-to-year differences in the seasonal cycle so that, for example, 

June in one year might be more typical of spring but in another year might be closer to summer 

conditions. Use of the 2-month seasons tends to produce fairly homogeneous data sets. 

Within each 0.5 0 x 1.0 0 area for each season, a logical method had to be chosen for averaging 

over time. Data from 25 time series (at 13 individual sites), generally of 6- to 25-h duration, 

2
 
Table 1. Seasonal mean standard errors of estimate (and their standard deviations) 

of surface and bottom temperature, surface and bottom salinity, and mixed-layer 

depth, using independent estimates as discussed in the text, for 1974-90 

Winter Spring Summer Fall 

(Feb.-March) (April-May) (July-Aug.) (Oct.-Nov.) 

No. of areas with 

three or more estimates 23 48 37 16 

Surface temperature (OC) 0.7 (0.3) 0.7 (0.4) 0.6 (0.4) 0.5 (0.2) 

Bottom temperature·(OC) 0.6 (0.4) 0.4 (0.4) 0.7 (0.4) 0.5 (0.2) 

Surface salinity (%0) 0.08 (0.05) 0.11 (0.06) 0.11 (0.06) 0.10 (0.12) 

Bottom salinity (%0) 0.09 (0.06) 0.07 (0.03) 0.08 (0.05) 0.09 (0.04) 

Mixed-layer depth (m) 11 (13) 6 (4) 3 (2) 8 (3) 

The standard deviations of the standard errors of the estimates are given in parentheses.
 

. For depths >100 m, values at 100 m are used as bottom values.
 

indicated small variations. The mean standard errors for these time series (standard deviations 

divided by the square root of the number of values) were as follows: surface temperature, 0.14°C; 

bottom temperature, 0.04 DC; surface salinity, 0.04%0; bottom salinity, 0.02%0; and mixed-layer 

depth, 7 m. It is thus apparent from these small values that data taken closely together in time are 

probably highly correlated and are not likely to be independent estimates. (There is also an 

implication that tidal effects, on the water properties used here, are small.) It was therefore decided 

to consider an "independent estimate" as the mean of all values within an area in an individual 

month, such as August 1980. (Means from time series stations were considered as single values.) 

The standard errors of these independent estimates are given in Table 1. The mean values for 

temperature and salinity are -0.6°C and -0.1%0, respectively. Thus contour intervals of 1.0°C and 

0.2%0 were used for the climatology. In general, the values in Table 1 reflect year-to-year or 

interannual variability; except for surface temperature and bottom temperature in shallow water, the 

interannual variability is greater than the seasonal variability discussed in Secs. 3.2-3.4. 

The number of independent estimates for each area for each of the four seasons is shown in 

Fig. 2. (Each area used had at least three independent estimates.) The number of estimates varied 

from 3 to 11. The mean numbers of estimates per area were 4.0, 5.5, 4.8, and 3.2 for winter, spring, 

summer, and fall, respectively (Fig. 2). The number of areas with three or more estimates were 23, 

48,37, and 16 for winter, spring, summer, and fall, respectively. The total number ofCTD stations 

used was 2239, with 269, 1330,475, and 165 being in winter, spring, summer, and fall, respectively. 

3. CLIMATOLOGY 

Seasonal maps of surface temperature, bottom temperature, surface salinity, bottom salinity, and 

mixed-layer depth are shown in this section and discussed. The data used extend over the period 

1974-90. In water depths >100 m, temperature and salinity values at 100 m are used, rather than 

actual bottom values, to allow more reasonable comparisons with near-bottom data in inshore 

waters. 

3
 
8O'N 

Independent_ 

WIn1Il' (Feb • Mer) 

8O'N 

Spmg (Apr • May) 

?;... 

,; I ':', I'! 

Bering Sea 

1:;-1"--, L::J I ' ....... ,..[ I 

.q 

J'I' " 

) co.. 'totlili 6 - I I ;,. j.. 

11 

55' 55' 

,;/j!Y. 

oJ '318 j? 

I -­

<;0j? . 

.......,... 

l7IY'W 165' 160' 155' 170"W 165' 160' 155' 

Independent estimates Swnme< (Jul - Aug) :tes 

8O'N 6O'N 

Bering Sea 

.q 

">. 

55' 55' 

"- "p. ·,-·'000 jr

., .........,es 

17O'W 1650 180' 1550 l7IY'W 165' 160' 155' 

Figure 2. Number of independent estimates in winter, spring, summer, and fall, 1974-90. 
3.1. Surface Temperature 

Surface temperature distributions for the four seasons are shown in Fig. 3. In all seasons, data 

are sparse north of 58 oN; in winter and fall, there are numerous data gaps elsewhere as well. In 

winter, temperatures vary from about -1 to 3°C, with the highest temperatures being near the 

Aleutian Islands. In spring, temperatures vary from about -1 to 4°C. Although spring temperatures 

north of 57 ON are similar to those in winter, waters to the south are _1°C warmer than in winter. 

In summer, temperatures vary only from about 8 to lo°C. The warmest water is near 56°N, from 

163 to 165°W. Fall temperatures vary only from about 7 to 8°C, except for one cool value north of 

59°N. ' 

3.2. Bottom Temperature 

South of 56°N, bottom water temperatures (Fig. 4) in winter are slightly warmer than surface 

temperatures. North of 57 ON near the 50-m isobath, temperatures at the two levels are similar. In 

spring, bottom water temperatures vary from about -1 to 4°C; they are slightly cooler than surface 

temperatures south of 57oN. Note the alignment of the 3°C isotherm along the Alaska Peninsula and 

similar features in summer and fall. This reflects advection of warm subsurface water through 

Unimak. Pass and along the north side of the Alaska Peninsula (see Fig. 1; Schumacher and Kinder, 

1983; Coachman, 1986). Bottom temperatures in summer vary from about 1 to 5°C. Note the large 

region of temperatures <2°C. In fact, some of the temperatures here are colder than in spring. This 

very likely results from substantial amounts of the summer data, but not the spring data, being from 

1976, which was a very cold year (discussed in Sec. 4). Another interesting feature in the summer 

data is that bottom temperatures inshore of 50 m near -57.8ON (Fig. 4) are -2-3 °c colder than at 

the surface (Fig. 3); shoal waters near the Alaska Peninsula have even more pronounced differences. 

This is surprising because of the consensus (Kinder and Schumacher, 1981; Coachman, 1986) that 

waters inshore of 50 m are generally well mixed because of combined tidal and wind stirring. Closer 

examination of their results, however, shows that small vertical gradients are not atypical. Fall has 

the warmest bottom waters (about 4 to 7°C, except for 1.8°C north of 59oN), but they are typically 

l-rC cooler than the surface waters. The waters inshore of 50 m are warmer than 7°C, which may 

result from both advection and enhanced vertical mixing in the shoal water. 

3.3. Surface Salinity 

Surface salinities are shown in Fig. 5. Crowding was avoided by omitting the first digits of the 

values listed (that is, 2.00 is actually 32.00(0). The winter values range from about 31.4 to 32.4%0; 

ranges and values in other seasons are similar, except both the range and the mean value in fall are 

smaller. The pattern of isohalines indicates low-salinity water in Unimak Pass extending 

northeastward along the Alaska Peninsula. This results from low-salinity coastal water from the Gulf 

of Alaska flowing through the pass (Royer, 1981; Schumacher et al., 1982); this water has lowest 

salinity in fall, as indicated in Fig. 5. 

3.4. Bottom Salinity 

Salinities near the bottom (Fig. 6) also show the effects of the low-salinity inflow through 

Unimak Pass. Salinities during the four seasons do not differ markedly. The range is typically from 

31.4 to 32.8%0, which is slightly larger than at the surface. Near the l00-m isobath, bottom values 

are generally about 0.5%0 greater than surface values. The highest bottom salinities (or values at 

100 m in greater depths), 33.1%0, are present west ofUnimak. Pass in summer. One speculation is 

that this might represent an enhanced inflow of oceanic water to the inner slope. 

5 
TsIc ("C) Tstc ('C) 

_(Feb-Mer) Spmg (Apr - May) 

8O"N 8O"N 

BeringSe8 

",. 

('"., 

55· 55· 

17fYW 165· 1110· 155· 17O"W 165· 160" 155· 

0'1 Tslc ('C) S.........r (Jul-.Aug) TsIc ("C) Filii (OCI- NoY) 

8O"N 8O"N 

" 

E3J 

"". 

J 

d 

55· 55· 

. . ,.J fP····· :.­ • 

'I AlM*nIl. 

17O"W 165· 160" 1550 17O"W 165· 160" 1550 

Figure 3. Sea surface temperature (OC) in winter, spring, summer, and fall, 1974-90. 
lIO'N lIO'N 

12 

, 

\' q 

/j '.'. J 

55' 55' 

17O"W 185' 160' 1550 l7O"W 165' 160' 155' 

Tbol ("C) Tbol ("C) 

-...J 

lIO'N 

Sumner (JIll • Aug) 

lIO'N i 

i t! 

I I I I tc:::=:P 1'6 i'\ , 

Fa. (OCI- Nov) 

j A­ i i '.' 1 

q 

"'

.. 

J 

55' 55' 

,J" , :i;g '"'P. 

.. ,J" •..!:. 

,';.0 

/ ,:;:3J y . 

_

.., 

l70"W 165' 160' 155' l7O"W 185' 160' 155' 

Figure 4, Bottom (or lOO-m; see text) temperature (OC) in winter, spring, summer, and fall, 
8O'N 8O'N 

.).4 

" 

55· 55· 

)7<Y'W 165· )llO" 1SS· 17O"W 165· 11lO" 155· 

0Cl 

8O'N 

Summer (JuI- Aug) 

8O'N 

Fal (OCI - Nov) 

r--.,-,,-....,..,-"-,,-....,.I"'==J1=JT,',,...r--r.";'}r""r-r'7'T'i 

4 

.. 

. ' 

J 

6 

SS· SS· 'i: 

_

... / 

,.. /.. /'::' 

..,,(jJ ".}' 

.. 

17<Y'W 165· 11lO" ISS· 17<Y'W 165· lllO" 1SS· 

Figure 5. Sea surface salinity (%0) in winter, spring, summer, and fall, 1974-90. The fIrst digit of 

each value was omitted; Le., 2.00 is actually 32.00%0. 
St>ot (01ool 

WInlIIr (Feb - Mar') 

8D"N 8D"N 

8«ingSeB 

12.6(: 

" 

'­

4 

4 

55· 55· 

l7O"W 165· 1110" 155· 170'W 165· 1110" 155· 

\0 8O"N 

St>ot (O/ool 

SOO1mer (Jul - Aug) 

8O"N 

St>ot (01ool 

FBI (0cI- Nov) 

G 

4 

"", 

55· 55· 

., ... 

l7O"W 165· 1110" 155­ l70'W 165· 1110" 155· 

Figure 6. Bottom (or lOO-m; see text) salinity (%0) in winter, spring, summer, and fall, 1974-90. 

Notation is as in Fig. 5. 
8O"N 

Ml(m) WInIltr (Feb • Mar) 

llO'N 

ML(m) Spdng (Apr • May) 

Bering Sea 

,

, 

<1 

.. 

d 

55' 55' 

17O'W 185' 160' 1550 l7O'W 165' 160' ISS' 

-

Ml(m) S_r(JuI- Aug) ML(m) FaR (OCI • Nov) 

o 8O"N llO'N 

-', 

\: <? 

J. 

-', J 

d 

55' 55' \ 

/ 

l7O'W 185' 160' ISS' l7O'W 165' 160' 1550 

Figure 7, Mixed-layer depth (m) in winter, spring, summer, and fall, 1974-90, 
3.5. Mixed-Layer Depth 

The depth of the mixed layer is defined here, according to Coachman (1986), as that depth at 

which sigma-t density increases from its surface value by 0.020 units. This definition has been used 

because ofthe importance of density structure to water column stability and possible impacts of tidal 

and wind stirring. Note that this level may not coincide with a thermal mixed layer. 

In winter (Fig. 7), the mixed layer is from -30 to 60 m; the greatest values are in the central 

region, and the least are near the Alaska Peninsula. In spring, the mixed layer is shoaler, ranging 

from -15 to 40 m. As expected, the shoalest mixed layers are in summer (from -10 to 20 m). In fall, 

the mixed layer ranges from -25 to 50 m, a rapid deepening from summer and generally deeper than 

in spring. As discussed above, mixed-layer depths near the 50-m isobath also indicate that the entire 

water column is not always mixed from top to bottom. . 

4. VARIATIONS 

Although climatological mean conditions are relevant to many problems, conditions during 

extreme years are also quite important. The year-to-year or interannual variability of water 

properties is examined here for the summer season. (Although more data are available overall for 

spring, they are concentrated over fewer years, of shorter duration, than for summer in the areas of 

interest.) Figure 8 shows the locations of the two areas used for generating time series of the yearby-year values of water properties in summer. Area 1 is between the 50- and loo-m isobaths, and 

area 2 is offshore in water deeper than 100m, where slope waters may intrude. 

600 N 

( 

"'-"""-,,, Bering Sea \. 

\ 

\ 

-;;~~, -. '"",-----, 

., \ '" ,.,---50 m -. , "­

'. \ <1 Area 1 ... -_.,,) '-,,-~

',- "........" .~ ,--' (~rea 21(\ // 6 

.... \, '/')/,/'/ ''' ~., fJ,0 .AA 

55° 0., " / •"9 :' ff ,,9. 

(\ ~~~__~P8SS •. 

,o/-p? _--_,/~·--,.osii1 r 11 Aleutian Is. JJ 

1700W 165° 160° 155° 

Figure 8. Locations of two areas used to examine interannual temperature variations 

in summer, 1975-84. 

11
 
(a) 

f 

------------1 

o	 Mean --- Mean 

1975 - 84 I Std. error 60 L....-	 ----J 

N-4 5 3 2 4 3 3 

4° C r----,.---r---.--.--..--.----.----.--i--..,-----, 

(b) 

}------- --------------------- ---------1
 

o Mean --­ Mean 

_20 I L....- Std. error 1975 - 84 -----' 

5 3 2 4 3 3 

Figure 9. Interannual temperature (OC) variations in summer at (a) the sea surface and 

(b) the bottom, in area 1 (see Fig.'8), 1975-84. 

The mean summer surface and bottom water temperatures in area 1 are shown in Fig. 9. Surface 

temperatures are somewhat variable, but only one year (1980) has means that depart from the 

1975-84 mean (dashed line) by as much as 2°C. Bottom water temperatures are more variable than 

surface temperatures; six of the eight values have significant departures from the long-term mean. 

Four years (1977, 1978, 1980, and 1981) are somewhat warmer than normal. The most striking 

feature, however, is the very cold conditions in 1976. Bottom temperatures then are >3°C below 

normal. The abnormally cold spring and summer 1976 conditions were discussed by Reed (1978), 

Ingraham (1981), and Coachman (1986); these were attributed to extensive ice cover the previous 

winter. Salinity data in this area (not shown) indicate that the only noteworthy anomaly was low 

surface salinity (by -0.5%0), but not bottom salinity, in summer 1976, which very likely resulted 

from addition of melt water from the ice that year. 

Mean summer temperatures for 1975-84 in area 2 (Fig. 8) are shown in Fig. 10. Water depths 

here are from 100 to -400 m; as noted above, l00-m temperatures are used rather than bottom 

temperatures. In Fig. 10, few of the surface or bottom temperature means are significantly different 

from the 1975-84 mean. Comparison of Figs. 9 and 10 demonstrates clearly the lack of convection 

of cold surface waters below -100 m in either normal winters or very cold ones like 1976. 

12
 
12° C .----..........,r--__r----.-----r-.....,....-....,...--~-_r__-r_____r-___.
 

(a) 

o 

------------I 

o	 Mean -_:.. Mean 

1975 - 84 I Std. error 60 '--	 ---' 

3 3 3 3 3 

(b) 

~--------~-------~
 

o	 Mean --- Mean 

1975 - 84 I Std. error 

0° '------------------------' 

N =2 3 3 3 3 3 

Figure 10. Interannual temperature (OC) variations in summer at (a) the sea surface and 

(b) 100 m, in area 2 (see Fig. 8), 1975-84. 

Specifically, l00-m long-term mean temperature in area 2 is >2°C warmer than in area I, and l00-m 

temperature in 1976 is not significantly colder than normal in area 2. 

5. DISCUSSION AND CONCLUSIONS 

It is not entirely clear how well the maps of climatological mean properties, based on 1974-90 

data, represent longer-term (over several decades) conditions. Ingraham (1981) presented 

climatological maps based on data from 1932 to June 1979, although a considerable portion of the 

data was for after 1955. His maps show somewhat colder conditions at the surface and bottom than 

those here in winter and spring; in summer and fall, however, the climatologies are similar. A 

similar comparison of salinity maps shows good agreement; his contour intervals are 1.0%0 though. 

Thus it seems likely that the maps here are not greatly different from long-term means. 

Swan and Ingraham (1984) presented bottom water temperature anomalies for 1950-82. For the 

region shown here, their time series indicated the coldest water (anomaly of -2.2°C) was in 1976; 

13
 
1971 and 1972 were next coldest (anomalies of -1.4 and -1.5°C). During the 1950s and 1960s 

bottom temperatures were Donnal or above; in the early and middle 1970s quite cold conditions 

prevailed; and warm conditions were typical in the late 1970s and early 1980s. At any rate, 1976 

appears to be the most extreme cold year since 1950. 

Extremely cold,water is produced by abnonnal winter ice conditions (Reed, 1978; Coachman, 

1986; Niebauer and Day, 1989). Niebauer and Day (1989) concluded that extreme ice production 

is caused by atmospheric, not oceanic, forcing. The winter position of the atmospheric Aleutian 

Low is the main factor. It, however, is linked to EI Nifio-Southern Oscillation (ENSO) events, which 

explain 30-40% of the variability in the Bering Sea. Thus extreme, aperiodic changes occur that are 

induced by an atmospheric teleconnection. 

6. ACKNOWLEDGMENTS 

I thank D. Kachel for preparing data products. J. Overland, J. Schumacher, P. Stabeno, P. 

Dell'Arciprete, and N. Bond provided support and advice. S. Stillwaugh helped obtain the data. This 

is contribution FOCI-B 237 to the Fisheries Oceanography Coordinated Investigations and is part 

of the Coastal Ocean Program of NOAA. 

7. REFERENCES 

Coachman, L.K., 1986. Circulation, water masses, and fluxes on the southeastern Bering Sea shelf. 

Cont. ShelfRes. 5:23-108. 

Favorite, F., 1974. Flow into the Bering Sea through Aleutian Island passes. In Oceanography of 

the Bering Sea. D.W. Hood and EJ. Kelley (Eds.), Occasional Publication No.2, University of 

Alaska, Fairbanks, 3-37. 

Ingraham, WJ., Jr., 1981. Shelf environment. In The Eastern Bering Sea Shelf: Oceanography and 

Resources, vol. 1. D.W. Hood and J.A. Calder (Eds.), NOAA Office of Marine Pollution 

Assessment (distributed by University of Washington Press, Seattle, WA), 455-469. 

Kinder, T.H., and J.D. Schumacher, 1981. Hydrographic structure over the continental shelf of the 

southeastern Bering Sea. In The Eastern Bering Sea Shelf: Oceanography and Resources, vol. 

1. D.W. Hood and J.A. Calder (Eds.), NOAA Office of Marine Pollution Assessment 

(distributed by University of Washington Press, Seattle, WA), 31-52. 

Niebauer, HJ., and R.H. Day, 1989. Causes of interannual variability in the sea ice cover of the 

eastern Bering Sea. GeoJournaI18:45-59. 

Reed, R.K., 1978. The heat budget of a region in the eastern Bering Sea, summer 1976. J. Geophys. 

Res. 83:3636-3645. 

Royer, T.C., 1981. Baroclinic transport in the Gulf of Alaska: Part II, Fresh water driven coastal 

current. J. Mar. Res. 39:251-266. 

Schumacher, J.D., and T.H. Kinder, 1983. Low-frequency current regimes over the Bering Sea 

Shelf. J. Phys. Oceanogr. 13:607-623. 

Schumacher, J.D., c.A. Pearson, and J.E. Overland, 1982. On exchange of water between the Gulf 

of Alaska and Bering Sea through Unimak Pass. J. Geophys. Res. 87:5785-5795. 

14 
Stabeno, P.J., and R.K. Reed, 1994. Circulation in the Bering Sea basin observed by satellitetracked drifters: 1986-1993. J. Phys. Oceanogr. 24: 848-854. 

Swan, N. P., and W. J. Ingraham, Jr., 1984. Numerical simulation of the effects of interannual 

temperature fluctuations on fish distribution in the eastern Bering Sea. NOAA Tech. Memo. 

NMFS FINWC-57, NOAA National Marine Fisheries Service, Seattle, WA, 60 pp. 

*U.S. GOVERN!lliNT PRINTING OFFICE:1995-673-01S/00110 

15