hydrographic conditions in the eastern pacific before during and after the 1982 83 el nino abstract between june 1981 and june 1984 a total of thirteen ctd sections were made across the equator along 85 w on some of these cruises additional sections were made along 5 s and 10 30 s between 85 w and the south american coast this sampling period covers the events that took place during the 1982 83 el nino these sections are used to describe the variability that took place before during and after this major event at the surface little evidence was found for a major southward flooding of warm low salinity water from north of the equator that has been observed during some previous el ninos major changes took place in the sub surface hydrographic structures the thermostad between 13 c and 16 c which is a prominent feature of the hydrography in this region disappeared early in 1983 and reappeared early in 1984 the vertical temperature gradient along the equator and along the coast which is usually quite variable with depth became much more uniform in early 1983 it regained its normal structure by early 1984 changes were not confined to the upper ocean but were evident over the whole depth interval sampled 1000m during november 1982 evidence was found for symmetric poleward spreading of the equatorial disturbance along the eastern boundary many of the changes that took place are consistent with linear models based on equatorial wave theory these observations presented a unique opportunity for observing the ocean response to a major interannual change in the wind forcing

dissolution kinetics of calcium carbonate in equatorial pacific sediments benthic chambers were deployed in the equatorial eastern pacific ocean on a transect along the equator between 103 w and 140 w and on a transect across the equator at 140 w in order to establish the rate of calcium carbonate dissolution on the seafloor dissolution was determined from the rate of alkalinity increase within an incubation chamber measured over an 80 120 hour incubation period dissolution rates were lowest at eastern pacific sites 0 2 0 4 mmol caco3 m2 d and highest at the equatorial 140 w sites 0 5 0 7 mmol m2 d both oxygen consumption rates and the degree of bottom water saturation govern dissolution rates measured dissolution and oxygen consumption rates are used with a numerical model to constrain the value of the dissolution rate constant k formulated according to the equation developed by keir 1980 dissolution rate k 1 n the observed dissolution fluxes are predicted by the model when k 5 to 100 d and n 4 5 this range of k values has important implications regarding the type of carbonate dissolving and its location within the sediment column at low values of k organic carbon rain rates to the seafloor become the dominant driving force of carbonate dissolution at higher values of k the degree of bottom water undersaturation becomes more important dissolution of carbonate within equatorial pacific sediments can be adequately described with k 20 10 d a rate constant much lower than some previously used values dissolution rates do not vary significantly over chamber boundary layer thicknesses between 200 and 800 m indicating that dissolution is not controlled by hydrodynamic conditions chambers acidified with hcl yield very large dissolution rates but for a given degree of acidification the dissolution rate was constant for sites ranging from water depths of 3300 4400 m this implies that there are not more and less easily dissolved forms of caco3 arriving on the seafloor between these depths a budget for alkalinity in the deep pacific predicted by the dissolution model and based on the assumption that all carbonate dissolution takes place in the sediments is within 85 of the input required by a published box model alkalinity budget based on the distribution of nutrients and the water mass transport rates

near bottom particle concentration and flux temporal variations observed with sediment traps and nepholometer on the meriadzek terrace bay of biscay abstract the meriadzek terrace a 2100m deep plateau on the north east atlantic continental slope was chosen as the experimental site for a multidisciplinary programme to observe the parameters needed for a better understanding of biological processes in the benthic environment two approaches were used to study the input of particulate matter to the bathyal seabed sediment traps and indirect particle concentration measurements with nephelometry these two technologies do not measure particles of the same size range but as we are interested in the fluctuations of the particle supply their results are complementary vertical profiles of nephelometry show that over the meriadzek terrace there is 125m thick nepheloid layer immediately above the bottom the dynamics in the deep layer has been determined by measurements made with a module autonome pluridisciplinaire map an in situ monitoring device developed at ifremer which measures currents nephelometry temperature vertical profile near the bottom throughout six months of measurements in 1984 the currents at 0 5m and 120m above the bottom were subject to semi diurnal tidal oscillations the intensity of light scattering recorded with the nephelometer on the map was highly correlated with current velocities especially with semidiurnal tidal oscillations which seem to induce local resuspension there are also longer term fluctuations notably a very strong event which lasted several days during august this event lagged behind a period of high intensity of internal waves correlated with a reversal in current direction the sediment trap pieges a particules pap observations showed that the particle fluxes on the meriadzek terrace have a cycle of variation similar to primary production which is characterized by a maximum in may during the phytoplankton bloom and a minimum during january there was also interannual fluctuation these two kinds of results point out the different time scales from some hours to several months of the large temporal fluctuations which affect the near bottom particle behaviour

response of vietnam coastal upwelling to the 1997 1998 enso event observed by multisensor data abstract in this paper we examine the behavior of the vietnam coastal upwelling during the 1997 1998 el nino southern oscillation enso event the baseline is 4 years of national oceanic and atmospheric administration noaa satellite advanced very high resolution radiometer avhrr sea surface temperature sst data taken from 1997 to 2000 comparison of upwelling images to simultaneous ers 2 european remote sensing satellite wind fields indicates that the summer monsoon winds constitute a major generation forcing during the 1997 el nino the monsoon winds enhanced the upwelling and induced the upwelling center to move southward during the 1998 la nina the monsoon winds weakened the upwelling in contrast with the tropical pacific in the study area la nina implies a warm event and el nino a cold event we use empirical orthogonal function eof methods to analyze the spatial and temporal variance of the upwelling the three principal modes account for 37 15 and 8 of the total variance respectively the first eof modes reveal that the sst variance in the north and south subregions underwent a positive negative sign switch in summer 1997 the second eof modes represent the monthly evolution in normal years the third modes seem to be sensitive to the 1998 la nina event simultaneous topex poseidon and ers 2 altimeter data provide further evidence for our analysis comparison with california coastal upwelling and mid atlantic bight mab coastal upwelling indicates that the vietnam coastal upwelling is the most intensive one

a three dimensional model of the mean and seasonal circulation of the gulf of california 1 the mean and seasonal circulation of the gulf of california is simulated with a three dimensional numerical model forced by the pacific ocean through specifying the sea level the temperature and the salinity fields at its entrance at the sea surface the wind and the heat and freshwater fluxes are specified the model reproduces the observed mean and seasonal variability of sea level of heat and salt balances and the sea surface temperature sst climatology it also reproduces the general surface circulation of the northern gulf which consists of a seasonally reversing basin wide gyre it is found that tides and heat fluxes are both indispensable to reproduce the spatial structure and temporal evolution of the sst tides provide the mixing to upwell the cooler subsurface waters in the large islands area and the heating from the surface raises the sst the general circulation of the southern part of the gulf is due to the wind and the pacific forcing in the ekman layer two periods of anticyclonic circulation and one cyclonic per year occur below this layer two cyclonic periods develop in the northern part the tides play an important role in producing mean residual currents and both tides and winds compete against the pacific forcing to produce a cyclonic and anticyclonic circulation once a year contrary to conclusions of previous studies the thermohaline circulation is found to be unimportant in the gulf

observations of annual and el nino thermal and flow variations at 0 110 w and 0 95 w during 1980 1985 moored measurements of the surface wind and of the current and temperature fields within the uppermost 250 m were recorded from march 1980 to september 1985 at 0 110 w and from july 1981 to november 1983 at 0 95 w at these sites the annual mean thicknesses of the equatorial undercurrent euc and of the surface portion of the south equatorial current sec were about 200 m and 20 m respectively the annual mean euc core speed was 0 9 m s 1 annual cycles of temperature and zonal current at 110 w were most distinctive near the surface at nominal depths of 15 m and 47 5 m the average annual amplitudes were 1 5 c and 0 5 m s 1 at about 100 m the annual amplitudes were about 0 5 c and 0 10 m s 1 at 15 m the annual mean zonal current was 0 05 m s 1 which was not representative of the monthly mean zonal current in april the monthly mean direction was eastward and in october it was westward with speeds of about 0 5 m s 1 in both months warmer water occurred in april and colder water in october the direction of the zonal wind component was westward throughout the year and the annual amplitude of the zonal wind was only about 2 5 times larger than that of the zonal current the average amplitude of the annual cycle of the meridional current component was less than 0 05 m s 1 and not distinguishable from year to year monthly mean variations monthly mean anomalous or el nino currents at 110 w were defined as the difference between the observations and the annual cycle during the august december 1982 onset phase of el nino the strength of the normally westward flowing near surface sec was greatly reduced to near zero speed by an el nino eastward flowing zonal current of about 0 3 m s 1 the largest vertically averaged 15 250 m zonal current anomaly 0 5 m s 1 occurred in january and february 1983 and represented a substantial decrease in the eastward transport of the euc causing a disappearance of the undercurrent the duration of the euc disappearance was longer at 95 w than at 110 w a surface intensified eastward jet with a maximum daily speed of 1 75 m s 1 at 15 m occurred in may 1983 at 110 w but not at 95 w a massive redistribution of heat throughout the mixed layer and thermocline was associated with the 1982 1983 el nino beginning in august 1982 the thermocline at 110 w and 95 w sank 100 m reaching its maximum depth in december 1982 temperatures at 100 m and 150 m which normally were about 15 c and 14 c reached 27 5 c and 22 5 c the time rate of change of the 15 to 200 m heat content was 500 w m 2 during the august december 1982 warming phase and 460 w m 2 during the january february 1983 subsurface cooling phase the euc disappeared during the subsurface cooling phase a second less intensive mixed layer deepening occurred in may 1983 at 95 w but not at 110 w

internal structure of sst features in the central gulf of california abstract closely spaced xbt and ctd data were used to study the sub surface structure of features observed in satellite avhrr sea surface temperature sst images of the gulf of california gc such as fronts jets and gyres the lowest ssts in the gc are found around the midriff islands and especially over the sills because of strong mixing from tidal currents and breaking internal waves this minimum sst area is limited to the south and north by sharp sst fronts which frequently show convolutions gyres and filaments a vertical section of temperature along the gulf length shows that about 300 km south of the sills the isotherms begin to spread out in the vertical reducing stratification the thermocline isotherms begin surfacing about 100 km south of the sill forming the sst minimum area which has a maximum temperature difference of 6 c with waters to the south and a horizontal sst gradient of 0 05 c km 1 the evolution and subsurface structure of a cool filament apparently originated as an instability of the sst front was intensely sampled satellite images show that its head advanced due south at about 0 5 ms 1 along the edge of a pool of warm surface water about 110 km in diameter the thermocline below the warm pool was raised at its edge and some isotherms reached the surface producing the cool filament the tilt of the temperature salinity and density isolines at the edge of the warm pool produced a geostrophic jet adjacent to the cool filament and just inside the warm pool with maximum speed 0 5 ms 1 and extending down to 80 m the filament lasted about 10 days its width was 30 km and it reached a maximum length of 120 km the volume transport of the jet in the top 100 m was around 0 7 sv

tidal and atmospheric forcing of the upper ocean in the gulf of california 1 sea surface temperature variability two years of satellite infrared imagery 1984 1986 are used to examine the sea surface temperature sst variability in the northern gulf of california empirical orthogonal functions eofs of the temporal and spatial sst variance for 20 monthly mean images show that the dominant sst patterns are generated by spatially varying tidal mixing in the presence of seasonal heating and cooling these patterns are modified in the fall and winter when shelf temperatures south of tiburon island cool in response to upwelling favorable winds these same winds bring cold dry air from off the continental united states causing local cooling of the shallow northern shelf during the rest of the year the broad shallow shelves are warmer than offshore the seasonally reversing temperature patterns are consistent with recent hydrographic observations which show a cyclonic surface circulation in the summer and a weaker anticyclonic circulation during the rest of the year atmospheric forcing of the northern gulf appears to occur over large spatial scales area averaged ssts for the guaymas basin island region and northern basin show significant fluctuations which are highly correlated these fluctuations in sst correspond to similar fluctuations in the air temperature which are related to synoptic weather events over the gulf during periods of particularly low wind speeds the air temperature over the gulf increases dramatically by afternoon intense heating of the sea surface results in the appearance of warm sst anomalies in the satellite data these ssts are approximately 2 c warmer than surrounding ssts and most likely occur as a result of a spatially varying wind field a regression analysis of the sst relative to the fortnightly tidal range shows that tidal mixing occurs over the sills in the island region as well as on the shallow norther shelf mixing over the sills however occurs as a result of large breaking internal waves or internal hydraulic jumps which mix water over the upper 300 500 m this mixing pumps heat away from the surface deep into the water column there by maintaining the cool ssts since mixing occurs over greater depths in the island region the temperatures there are much colder than those generated by tidal mixing on the shallow shelves resulting in the persistent pool of cool water evident in the satellite data this cooler water is mixed horizontally by the basin scale circulation lowering the ssts over much of the northern gulf these reduced ssts have a large impact on the surface heat flux by lowering the saturation vapor pressure of the air as a result the amount of heat lost to the atmosphere through the latent or evaporative heat flux is reduced this may explain why the gulf of california gains heat on an annual average rather than losing heat as occurs in the mediterranean and red seas where tidal mixing is not significant

on the three dimensional numerical modeling of the deep circulation around angel de la guarda island in the gulf of california a three dimensional nonlinear baroclinic model is used to model the circulation in the ballenas channel gulf of california mexico which was inferred from current meter observations over three sills that surround the area the suggested circulation consists of deep inflow that follows two paths the first one is a direct spill of water through san lorenzo sill into ballenas channel the second one a larger route that starts at san esteban sill then flows north of the island passing over tiburon and delfin basins and then turns to the south reaching the north ballenas channel sill and then spills into ballenas channel following the latter result a previous modeling effort to reproduce the circulation was partially obtained the long path was not reproduced and it was believed that finer horizontal resolution was needed in this work the bathymetric resolution was increased by a factor of three and the full path of this deep circulation is now obtained and corroborated

meteorologically forced subinertial flows through the strait of gibraltar the observed transport due to subinertial flows with periods ranging from days to a few months through the strait of gibraltar reaches values up to 106 m3 s 1 and is well correlated with atmospheric pressure fluctuations over the mediterranean sea this transport is barotropic and accounts for 84 of the variance observed at these frequencies a second mode accounts for 12 of the variance and is characterized by a node zero amplitude located at the mean depth of the interface between atlantic and mediterranean waters this baroclinic mode is modulated by the spring neap tidal cycle corresponding to an increased exchange of waters between atlantic and mediterranean at neap tides a simple model of the mediterranean which includes two basins and two straits indicates that the system has two resonant frequencies at periods of 1 2 and 5 6 days the 1 2 day resonance corresponds to the eastern and western basins oscillating through the strait of sicily while that at 5 6 days is the resonance of the mediterranean sea with the north atlantic ocean a good approximation to the observed flows is obtained when this model is forced with the most energetic mode of the atmospheric pressure over the eastern and the western mediterranean and a friction term is included to limit the flow through the strait of gibraltar restricting the flow through the strait of sicily does not improve the agreement between the model and the observations for the flows at gibraltar

off equatorial influence upon pacific equatorial dynamic height variability during the 1982 1983 el nino southern oscillation event anomalous sea level anomalous observed dynamic height 0 400 dbar and anomalous model dynamic height are compared at the locations of 13 island sea level stations in the tropical pacific for each 2 month interval of the 4 year period 1979 to 1982 sea level compares well with both observed dynamic height 0 400 dbar based on temperature depth observations made by volunteer observing ships and model dynamic height derived from a linear two layer wind driven model the cross correlation between sea level and either of the dynamic heights is generally greater than 0 75 the ratio of root mean square rms differences about the mean annual cycle of the sea level to rms differences of either of the dynamic heights is approximately unity starting in 1981 off equatorial rossby wave activity propagated toward the western boundary of the pacific basin this also occurred in model dynamic height both north and south of the equator yet neither sea level observations nor observed dynamic height has the spatial and temporal resolution to establish a connection between the off equatorial rossby wave activity and the equatorial kelvin wave activity in the western boundary region on the other hand the model dynamic height does have this capability therefore at the western boundary the model rossby wave activity is found to have excited coastally trapped kelvin munk wave activity which transmitted the anomalous sea level equatorward at the equator this model coastally trapped wave activity excited eastward propagating equatorial kelvin waves yielding a pair of anomalous peaks in dynamic height variability in the eastern equatorial pacific associated with the 1982 1983 el nino southern oscillation enso event the evolution of these two peaks in anomalous dynamic height associated with the 1982 1983 enso event is examined at eight locations in the tropical and equatorial pacific the major peak originated in the off equatorial south pacific and coincided with the wintertime 1982 1983 el nino event in the eastern equatorial pacific the secondary peak originated in the off equatorial north pacific and coincided with the anomalous peak which occurred in the eastern equatorial pacific the summer before the 1982 1983 enso event

benthic respiration and standing stock on two contrasting continental margins in the western indian ocean the yemen somali upwelling region and the margin off kenya during the netherlands indian ocean project niop 1992 1993 sediment community oxygen consumption scoc was measured on two continental margins in the indian ocean with different productivity the productive upwelling region off yemen somalia and the supposedly less productive kenyan margin which lacks upwelling the two margins also differ in terms of river input kenya and the more severe oxygen minimum in the arabian sea simultaneously with scoc distributions of benthic biomass and phytodetritus were studied our expectation was that benthic processes in the upwelling margin of the arabian sea would be relatively enhanced as a result of the higher productivity on the kenyan margin scoc range 1 36 mmol m 2 d 1 showed a clear decrease with increasing water depth and little temporal variation was detected between june and december highest scoc values of this study were recorded at 50 m depth off kenya with a maximum of 36 mmol m 2 d 1 in the northernmost part on the margin off yemen somalia scoc was on average lower and showed little downslope variation 1 8 5 7 mmol m 2 d 1 notably during upwelling when the zone between 70 and 1700 m was covered with low o 2 water 10 50 mu m after cessation of upwelling scoc at 60 m depth off yemen increased from 5 7 to 17 6 mmol m 2 d 1 concurrently with an increase of the near bottom o 2 concentration from 11 to 153 mu m suggesting a close coupling between scoc and o 2 concentration this was demonstrated in shipboard cores in which the o 2 concentration in the overlying water was raised after the cores were first incubated under in situ conditions 17 mu m o 2 this induced an immediate and pronounced increase of scoc conversely at deeper stations permanently within the oxygen minimum zone omz scoc showed little variation between monsoon periods hence organic carbon degradation in sediments on a large part of the yemen slope appears hampered by the oxygen deficiency of the overlying water macrofauna biomass and the pooled biomass of smaller organisms estimated by the nucleic acid content of the sediment had comparable ranges in the two areas in spite of more severe suboxic conditions in the arabian sea at the kenyan shelf benthic fauna macro and meiofauna largely followed the spatial pattern of scoc i e high values on the northern shelf upper slope and a downslope decrease on the yemen somali margin the macrofauna distribution was more erratic nucleic acids displayed no clear downslope trend on either margin owing to depressed values in the omz perhaps because of adverse effects of low o 2 on small organisms meiofauna and microbes phytodetritus distributions were different on the two margins whereas pigment levels decreased downslope along the kenya margin the upper slope off yemen 800 m had a distinct accumulation of mainly refractory carotenoid pigments suggesting preservation under low o 2 because the accumulations of c org and pigments on the yemen slope overlap only partly we infer a selective deposition and preservation of labile particles on the upper slope whereas refractory material undergoes further transport downslope keywords deep sea sediments organic matter oxygen uptake boundary layer arabian sea carbon degradation phytoplankton chlorophylls carotenoids

benthic chamber and profiling landers in oceanography a review of design technical solutions and functioning we review and evaluate the design and operation of twenty seven known autonomous benthic chamber and profiling lander instruments we have made a detailed comparison of the different existing lander designs and discuss the relative strengths and weaknesses of each every aspect of a lander deployment from preparation and launch to recovery and sample treatment is presented and compared it is our intention that this publication will make it easier for future lander builders to choose a design suitable for their needs and to avoid unnecessary mistakes

thermohaline circulation in the gulf of california the gulf of california a narrow semienclosed sea is the only evaporative basin of the pacific ocean as a result of evaporative forcing salinities in the gulf are 1 to 2 higher than in the adjacent pacific at the same latitude this paper examines the thermohaline structure of the gulf and the means by which thermohaline exchange between the pacific and the gulf occurs over time scales of months to years in addition to evaporative forcing air sea heat fluxes and momentum fluxes are important to thermohaline circulation in the gulf from observations presented here it appears that the gulf gains heat from the atmosphere on an annual average unlike the mediterranean and red seas which have comparable evaporative forcing as a result outflow from the gulf tends to be less dense than inflow from the pacific winds over the gulf change direction with season blowing northward in summer and southward in winter this same seasonal pattern appears in near surface transports averaged across the gulf the thermohaline circulation then consists of outflow mostly between about 50 m and 250 m inflow mostly between 250 m and 500 m and a surface layer in which the direction of transport changes with seasonal changes in the large scale winds using hydrographic observations from a section across the central gulf total transport in or out of the northern gulf is estimated to be 0 9 sv heat gain from the atmosphere is estimated to be 20 to 50 w m 2 and evaporation is estimated to be 0 95 m yr 1 these estimates are annual averages based on cruises from several years seasonal variations in thermohaline structure in the gulf are also examined and found to dominate the variance in temperature and density in the top 500 m of the water column salinity has little seasonal variability but does exhibit more horizontal variablility than temperature or density major year to year variations in thermohaline structure may be attributable to el nino southern oscillation events

earth s variable rotation recent improvements in geodetic data and practical meteorology have advanced research on fluctuations in the earth9s rotation theinterpretation of these fluctuations is inextricably linked with studies of the dynamics of the earth moon system and dynamical processes in the liquid metallic core of the earth where the geomagnetic field originates other parts of the earth9s interior and the hydrosphere and atmosphere fluctuations in the length of the day occurring on decadal time scales have implications for the topography of the core mantle boundary and the electrical magnetic and other properties of the core and lower mantle investigations of more rapid fluctuations bear on meteorological studies of interannual seasonal and intraseasonal variations in the general circulation of the atmosphere and the response of the oceans to such variations

two overflows in the northern gulf of california 1 two overflows originating at sills in the northern gulf of california are marked by strong average downstream slopes of 17 and 4 near bottom stratification upstream of both sills is relatively strong but the near bottom water is very well mixed downstream of the sills the homogenization of a thick bottom layer downstream albeit close to the sills is indicative of very strong mixing waters in the downstream basins are well ventilated with relatively high oxygen concentrations these hydrographic patterns were observed during three different seasons time series of temperature salinity and potential density show that water flowing over the sills is essentially subsurface subtropical water from the pacific ocean the time series also indicate that water is nearly always denser at the sills compared to water in the downstream basins despite the two fold 800 m and more than three fold 1500 m increase in depth the long term more than a year average current at both sills is bottom intensified with maximum average speeds of 33 and 17 cm s there are also strong tidal currents at the sills although the subinertial currents near the bottom are quite persistent with nearly no flow reversals transports estimated exclusively with the mean flow are about 0 08 and 0 09 sv 1 sv 1 106 m3 s which agree well with previous estimates based on shorter time series and a lower vertical resolution these results indicate that the deep water at both downstream basins are renewed by these overflows which enter at sill depths 400 m and are capable of reaching the deepest part of both basins the overflows appear to be responsible for the main mechanisms that transform subsurface subtropical water into gulf of california water

pore water advection and solute fluxes in permeable marine sediments i calibration and performance of the novel benthic chamber system sandy this contribution introduces the benthic chamber system sandy that was developed for studying in situ solute fluxes in permeable sandy sediments where advective pore water transport can dominate solute exchange across the sediment water interface the sandy system can be deployed at the seafloor where it autonomously performs measurements of sediment water solute fluxes the innovative features include an insertion mechanism that permits gentle and deep penetration of the chamber into hard consolidated sands with minimum disturbance and an adjustable stirrer that generates a rotationally symmetric pressure gradient between the center and the circumference of the enclosed sediment surface in contrast to similar systems sandy takes advective pore water exchange into account through adjustment of the stirring rate defined pressure gradients can be established that are similar in shape and magnitude to natural pressure gradients that develop at topographical structures of current exposed sediment surfaces solute fluxes measured in the chamber at a specific advective stirrer setting can be compared with those obtained at reduced stirring where pressure gradients are absent and solute exchange therefore is restricted to diffusion and bioirrigation rates of pore water exchange that were determined by means of tracer experiments at different stirrer settings in natural coarse grained north sea deposits demonstrate the feasibility of this approach this permits for the first time an evaluation of the contribution of advective exchange to the total interfacial solute flux in situ and makes sandy a valuable tool to study advection related processes in permeable shelf sediments

geosat crossover analysis in the tropical pacific 2 verification analysis of altimetric sea level maps with expendable bathythermograph and island sea level data altimetric sea level map time series of the tropical pacific have been produced from the crossover differences generated in the first 17 months of the geosat mission to verify the validity of altimetric sea level so produced they are compared with the dynamic height field derived by expendable bathythermograph xbt and island sea level data overall the three fields show statistically significant correlation with each other at island sea level stations altimetric sea level in general has better correlation with island sea level than the xbt derived dynamic height complex empirical orthogonal function ceof analysis which is used to discern coherent structures from data contaminated by random errors has been conducted on the altimetric sea level and xbt derived dynamic height field the first ceof modes which each explain 70 of the variance of the respective field correlate significantly better with each other than the original fields the relatively short record is clearly dominated by the annual signal major features away from the equator are also observed to propagate to the west

nitrogen cycling in deep sea sediments of the porcupine abyssal plain ne atlantic rates of transformation recycling and burial of nitrogen and their temporal and spatial variability were investigated in deep sea sediments of the porcupine abyssal plain pap ne atlantic during eight cruises from 1996 to 2000 benthic fluxes of ammonium nh4 and nitrate no3 were measured in situ using a benthic lander fluxes of dissolved organic nitrogen don and denitrification rates were calculated from pore water profiles of don and no3 respectively burial of nitrogen was calculated from down core profiles of nitrogen in the solid phase together with 14c based sediment accumulation rates and dry bulk density average nh4 and no3 effluxes were 7 4 19 mu mol m 2 d 1 n 7 and 52 30 mu mol m 2 d 1 n 14 respectively during the period 1996 2000 during the same period the don flux was 11 5 6 mu mol m 2 d 1 n 5 and the denitrification rate was 5 1 3 0 mu mol m 2 d 1 n 22 temporal and spatial variations were only found in the benthic no3 fluxes the average burial rate was 4 6 0 9 mu mol m 2 d 1 on average over the sampling period the recycling efficiency of the pon input to the sediment was 94 and the burial efficiency hence 6 the don flux constituted 14 of the nitrogen recycled and it was of similar magnitude as the sum of burial and denitrification by assuming the pap is representative of all deep sea areas rates of denitrification burial and don efflux were extrapolated to the total area of the deep sea floor 2000 m and integrated values of denitrification and burial of 8 5 and 7 1 tg n year 1 respectively were obtained this value of total deep sea sediment denitrification corresponds to 3 12 of the global ocean benthic denitrification burial in deep sea sediments makes up at least 25 of the global ocean nitrogen burial the integrated don flux from the deep sea floor is comparable in magnitude to a reported global riverine input of don suggesting that deep sea sediments constitute an important source of don to the world ocean

internal waves in the gulf of california observations from a spaceborne radar pronounced signatures of internal waves were detected repeatedly in the gulf of california by the seasat synthetic aperture radar sar a series of nine images with exactly repeating ground coverage was used to study the temporal variability of the internal wave field in the area it was found that the number of observed wave groups was highly correlated with the strength of the local tides the maximum number occurred during spring tides and the minimum number occurred during neap tides indicating that the internal waves were tidally forced most of the wave activity was found to the north of 28 n where the tides were the strongest in the gulf the application of a simple nonlinear internal wave model to the observations indicated that the peak to peak amplitude of the observed waves was about 50 m with an uncertainty of a factor of 2 the estimated upper bound for the rate of the loss of tidal energy to internal waves was about 5 1015 erg s representing only 10 of the rate of the dissipation of the dominant m2 tide in the gulf

dissolution of calcite in deep sea sediments ph and o2 microelectrode results abstract we present microelectrode profiles of oxygen ph and porosity measured at in situ depth across the sediment water interface from stations above and below the calcite saturation horizon in the equatorial atlantic resistivity electrode data indicate that the diffusion coefficient for solutes is attenuated by nearly a factor of two within the top centimeter of the sediment lattice oxygen and porosity data are used to estimate that the organic carbon respiration rate of the sediment is 10 15 mol cm 2 yr 1 in these locations comparison of the ph data with numerical model results reveals that sedimentary calcite dissolves in response to respiration in the top few centimeters of sediment even above the saturation horizon we calculate that the effective in situ dissolution rate constant for calcite required to explain these data is the neighborhood of 10 100 d 1 although more data are needed to confirm this result it appears to be at least an order of magnitude less than the rate observed in laboratory stirred reactor experiments

on the variability of tidal fronts on a macrotidal continental shelf northern patagonia argentina abstract tidal fronts are associated with the transition between homogeneous and vertically stratified water and are characterized by the simultaneous availability of light and nutrients that enhance the growth of marine productivity we study the variability in the position of two tidal fronts located in patagonia argentina the san matias and valdes fronts the rate of tidal dissipation in these regions is among the highest of the world oceans the study is based on the analysis of over 1200 satellite derived sea surface temperature images the results indicate that the mean monthly position of both fronts is strongly linked to the characteristics of the bottom topography in response to increasing surface heat flux the fronts displace toward shallower areas similarly a slight displacement towards deeper waters is observed when the heat flux decreases high frequency variability is revealed by the standard deviation around monthly averages at the mouth of the san matias gulf the front location variability in the spring neap cycle is around 10 km while east of the valdes peninsula the fortnightly cycle is masked by high frequency fluctuations 30 km governed by meanders and meso scale filaments a simple conceptual model is proposed which suggests that the mean frontal position is determined by the bottom topography while its seasonal variability is driven by the surface heat flux and the front intensity is modulated by the spring neap transition

summer sea surface temperature variability off vancouver island from satellite data satellite sensed advanced very high resolution radiometer avhrr sea surface temperature sst data over eight summers 1984 1991 were used to analyze the summer sst patterns of variability off the west coast of vancouver island empirical orthogonal function eof analysis of the spatial variance for 133 nearly cloud free summer images was performed the first eof mode which resembled the mean of all images showed a strong cool water band located at the northwest comer of vancouver island a cool tongue extending seaward from the strait of juan de fuca and a warm patch off barkley sound the second mode revealed topographically controlled upwelling cool water over the shelf region with its seaward boundary roughly following the 200 m depth contour plus a cold eddy located just north of the juan de fuca canyon the third mode displayed cool water extending southwestward off brooks peninsula while the fourth mode showed a cool water plume extending off cape scott at the northern tip of vancouver island these four modes accounted for 33 12 10 and 5 of the sst variance respectively the temporal amplitude of these eof modes revealed how the sst features changed as summer progressed from these images we also constructed an overall seasonal coolness index which revealed the summers of 1986 and 1991 to have the coolest coastal water with both summers immediately preceding an e1 nifio

equatorial undercurrent disappears during 1982 1983 el nino the equatorial undercurrent at 159 w decayed during august 1982 partially reversed during september and rapidly reappeared in january 1983 the virtual disappearance is consistent with the basin wide adjustment of sea surface slope to the strong westerly winds in the western and central pacific that caused the 1982 1983 el nino event

tidal dissipation and stratification in the gulf of california the effect of tidal mixing upon the distribution of stratification and sea surface temperature sst in the gulf of california is studied by direct observation and by numerical modeling data from conductivity temperature depth surveys made in september and december of 1986 are used to describe the distribution of stratification and sst a vertically integrated finite differences numerical model was used to obtain the geographical distribution of available turbulent kinetic energy tke from the m2 tide the following three areas were found to be strongly affected by tidal mixing the shallow coastal area at the head of the gulf the shelf south of tiburon island and the area of the midgulf archipelago the first two are vertically well mixed and are therefore similar to other shelf sea frontal areas dissipation occurs all around the islands of the archipelago and the sills are foci of the most intense tidal dissipation stratification in this area was reduced with respect to the background but complete vertical mixing does not occur therefore the strong sst fronts that occur in this area do not mark the boundary between well mixed and stratified water the simpson hujiter criterion simpson and hunter 1974 for stratification and frontal position produced 2 75 crit 3 0 for the frontal position in the shallow northern gulf this value of crit is larger than in other shelf sea fronts which may be due to horizontal advection which is not included in the criterion we found that the effect of advection may be of the same order of magnitude as that of buoyancy flux in the area over the sills criti the available tke is not enough to produce complete mixing over the 400 m of water over the sills

an improved real time global sea surface temperature analysis abstract the monthly global sea surface temperature sst analysis of reynolds using real time in situ and satellite sst data has now been improved by using sea ice data to simulate ssts in ice covered regions the simulated ssts now become the external boundary condition for the analysis solution this technique eliminates any high latitude satellite biases and extends the analysis to the ice edge the analysis with the ice data has been computed for the period january 1982 to present

seasonal variability of sea surface temperature fronts on georges bank abstract sea surface temperature sst fronts extracted from archived 1985 1996 advanced very high resolution radiometer avhrr data are determined in the georges bank region resulting frontal locations clearly show the tidal mixing front on georges bank the probability of detecting an sst front at an individual pixel on georges bank is presented as a monthly climatology variations in the probability position and associated water depth of sst fronts in the georges bank region show the development of the tidal mixing front during the summer as well as the presence of a persistent front near the shelfbreak from the 12 yr time series of fronts 144 individual monthly frontal probability images are decomposed into the mean frontal position and empirical orthogonal functions eof using singular value decomposition svd spatial and temporal information from the first eof mode reveals the seasonal development of the tidal mixing front spatial patterns associated with the first mode also reveal the winter occurrence of fronts on the northeast peak area of georges bank which is most likely associated with scotian shelf water flow across the northeast channel the second mode also indicates the development of the hot spot often observed over georges bank during the late summer and early fall further evidence indicates that the mean position of detected sst fronts on southern georges bank changes approximately 10 km on bank from late spring to mid summer monthly mean positions are also compared to the distribution of simpson and hunter s 1974 tidal mixing parameter with resultant positions compared to historical stratification at those locations comparison of detected sst fronts to historical hydrographic data on georges bank points to the fronts being located in increasingly stratified water from may through august

ocean currents across the entrance to the gulf of california observations of transport and currents in april may and december 1992 and january 1993 were made across the entrance to the gulf of california with an acoustically tracked dropsonde flow was into the gulf along sinaloa and out of the gulf along baja california the transports were 5 10 sv and the currents were deep with 10 cm s 1 flow extending to depths greater than 1000 m the currents were intensified in the upper 300 m geostrophic flows compared well with observed currents when smoothed to 2 3 times the rossby radius salinity in the upper 300 m was higher on the baja california side of the gulf indicating modification of subtropical subsurface waters within the gulf as well as the presence of surface and near surface gulf waters the salinity minimum associated with california current waters at 50 m had narrow cores that can be resolved only with closely spaced conductivity temperature depth casts mass and heat fluxes for the upper 300 m were estimated as 280 t s 1 and 0 1 1012 w in may and 170 t s 1 and 2 0 1012 w in december

ocean color observations of eddies during the summer in the gulf of california 1 using seawifs ocean color satellite images collected during 1997 2001 a series of eddies have been observed in the gulf of california these eddies are not clearly seen in the summertime sea surface temperature images the surface circulation between the midriff islands and the mouth of the gulf appears to be dominated by this series of eddies that have an alternating sense of rotation an eddy pair is observed to extend from cabo lobos in each of the three years suggesting that the eddies are topographically locked the formation mechanism of the eddies remains unknown however we suspect the most likely mechanism includes baroclinic instabilities along the coast produced by interactions between coastally trapped waves and local wind driven currents

imbalance in the carbonate budget of surficial sediments in the north atlantic ocean variations over the last millenium abstract fluxes contributing to the particulate carbonate system in deep sea sediments were investigated at the bengal site in the porcupine abyssal plain northeast atlantic deposition fluxes were estimated using sediment traps at a nominal depth of 3000 m and amounted to 0 37 0 1 mmol c m 2 d 1 dissolution of carbonate was determined using flux of total alkalinity from in situ benthic chambers is 0 4 0 1 mmol c m 2 d 1 burial of carbonate was calculated from data on the carbonate content of the sediment and sedimentation rates from a model age based on 14c dating on foraminifera 0 66 0 1 mmol c m 2 d 1 burial plus dissolution was three times larger than particle deposition flux which indicates that steady state is not achieved in these sediments mass balances for other components bsi 210pb and calculations of the focusing factor using 230th show that lateral inputs play only a minor role in this imbalance decadal variations of annual particle fluxes are also within the uncertainty of our average long term change in dissolution may contribute to the imbalance but can not be the main reason because burial alone is greater than the input flux the observed imbalance is thus the consequence of a large change of carbonate input flux which has occured in the recent past a box model is used to check the response time of the solid carbonate system in these sediments and the time to reach a new steady state is in the order of 3 kyr thus it is likely that the system has been perturbed recently and that large dissolution and burial rates reflect the previously larger particulate carbonate deposition rates we estimate that particulate carbonate fluxes have certainly decreased by a factor of at least 3 and that this change has occurred during the last few centuries

diurnal cycle of surface flows during 2004 name and comparison to model reanalysis abstract during the north american monsoon experiment name an unprecedented surface dataset was collected over the core monsoon region observations from 157 surface sites in this region along with twice daily quick scatterometer quikscat oceanic winds were quality controlled and processed into a gridded dataset covering the domain 15 40 n 90 120 w at 1 h 0 25 resolution for the period from 1 july to 15 august using this dataset the mean temporal variability and diurnal characteristics of the monsoon surface flow are documented with detail not previously possible being independent of model data over land these objectively analyzed surface products are compared to similar analyses from a special north american regional reanlysis for name narr name that was produced for the same period observed surface fields indicate that a robust land sea breeze circulation is present over most of the gulf of california goc region in response to the strong diurnal heating of landmasses on both sides

summer generation of the southern gulf of california eddy train 1 ocean color and sea surface temperature satellite observations show the existence of a series of anticyclonic eddies along the axis of the southern gulf of california sgoc to investigate the summer generation of these eddies a regional version of the hybrid coordinate ocean model hycom has been configured for the goc and has been nested inside the global model a suite of experiments using the nested goc model was developed and used to isolate the effects of the local wind and the effects of the oceanic remote forcing on the generation of the sgoc eddies the results indicate that the local wind is not essential for the generation of these eddies rather it is the oceanic remote forcing in the sgoc the monthly variability of the currents and sea surface height is mainly due to the deterministic near coastal poleward eastern boundary currents pebc the interaction of the pebc with the topographic irregularities the capes at topolobampo and cabo lobos and the ridges extending offshore from the entrance of the san lorenzo and sinaloa rivers generates the sgoc eddies the northward upper ocean transport induced by the pebc includes two maximums one in may june and the other in december during the summers of 1999 and 2004 the pebc were intensified by the arrival of equatorially originated downwelling coastally trapped waves ctws which contributed to the generation of the sgoc eddies the summer 2004 ctw increased the northward upper ocean transport by 2 sv this particular ctw was measured by several tide gauges located along the coast

analysis of the seasonal and interannual variability of the sea surface temperature field in the adriatic sea from avhrr data 1984 1992 seasonal and interannual variability of the sea surface temperature field in the adriatic sea is analyzed from the low resolution advanced very high resolution radiometer data the spatial resolution of 18 km allowed analysis of only basin and subbasin scale features average monthly and seasonal sea surface temperature fields for the entire studied period 1984 1992 are discussed the analysis shows the absence of any permanent sea surface thermal features in the adriatic sea the south adriatic sea surface temperature minimum presumably associated to the cyclonic gyre previously considered as one of the permanent features appears to be recurrent being prominent only in late autumn and early winter i e in the preconditioning and a deepwater formation phases the major ionian water inflow is documented in autumn while the thermal signature of the western surface outflow of adriatic water appears most prominent in winter the variability of the basin wide thermal pattern in the adriatic reveals four distinct seasons which is different from both the eastern and western mediterranean where only two major patterns are recognized a prominent interannual signal occurs in a northward extension of the warm water plume along the eastern coast which in some years reaches the northernmost corner of the adriatic while in other situations it remains trapped in the south adriatic cyclonic gyre the surface thermal signature of the south adriatic gyre also varies on an interannual timescale and it was weak or completely absent during the period 1984 1986 while it was rather prominent in the period 1987 1992 a constant trend of sea surface temperature decrease in the center of the south adriatic gyre and in the northernmost corner of the adriatic was evidenced over the studied period

surface heat flux in the northern gulf of california recent coastal meteorological data 1979 1986 are used to evaluate the seasonal cycle of surface heat fluxes in the northern gulf of california although net heat loss occurs from october to january the annual mean of the net surface heat flux was found to be into the sea 69 w m 2 near the coast and 83 w m 2 offshore with a mean evaporation rate 0 9 m yr 1 these results require an oceanic export of heat and salt out of the northern gulf to achieve a balance and imply that the annual mean thermohaline circulation must have an inflowing component at depth thus enriching the central and northern parts of the gulf these results differ from previous meteorological estimates which suggested a net surface heat loss but confirm those based on hydrographic data

trophic control of benthic foraminiferal abundance and microhabitat in the bathyal gulf of lions western mediterranean sea surface sediment was sampled at two bathyal sites in the southwestern gulf of lions in the western mediterranean sea in february and august 1997 to study the distribution and microhabitat of living rose bengal stained deep sea benthic foraminifera both standing stock and diversity of the faunas and the microhabitat of distinct species mirror the trophic situation and the depth of the oxidised layer at the different sites our results suggest that the faunas do not comprise highly opportunistic species and are adapted to rather stable environments in the axial channel of the lacaze duthiers canyon organic matter fluxes are enhanced due to advective transport of organic matter resulting in elevated oxygen consumption rates in the surface sediment and a rather thin oxidised layer the corresponding benthic foraminiferal fauna is characterised by rather high standing stock and diversity and a well developed deep infauna in addition to freshly deposited phytodetritus more degraded organic matter seems to be an important food source in contrast at the open slope organic matter fluxes and oxygen consumption rates in the surface sediment are lower and the oxidised layer is much thicker than inside the canyon the corresponding benthic foraminiferal fauna comprises mainly epifaunal and shallow infaunal species with much lower standing stocks and clear differences between february and august in august standing stocks are higher and the average living depths of most species shift towards the sediment surface these differences can be attributed to patchiness or represent a seasonal trophic signal

hindcasts of sea level variations during the 1982 83 el nino abstract the sea level signature for the onset of the 1982 83 el nino is hindcasted using a linear wind driven model that consists of four vertical modes the hindcast solution is compared with sea level time series from 18 island and coastal stations throughout the tropical pacific the response of the first and second baroclinic modes when summed account for a significant portion of the phase and amplitude of the observed sea level the comparisons with observed sea level are best in the eastern tropical pacific along the equator and south american coast where the solutions are a function of integrals of the zonal wind field to the west the skill of the hindcast is notably less away from the equator

tidal mixing signatures in the indonesian seas from high resolution sea surface temperature data the presence of significant tidal mixing in the indonesian seas is well established from both observations and numerical modeling one indicator is a clear spring neap cycle in satellite sea surface temperature sst measurements as first shown by ffield and gordon their early results are here updated with sst data of considerably higher spatial and temporal resolution the largest fortnightly signals are found to be localized to relatively small straits channels and sills while the deep basin of the banda sea displays little significant signal a broader region of somewhat enhanced signal surrounds the seram sea the high resolution of the modern sst data is especially critical for mapping the complex fortnightly signals that arise in and especially south of the major straits of the lesser sunda island chain

the cycling and oxidation pathways of organic carbon in a shallow estuary along the texas gulf coast abstract the cycling and oxidation pathways of organic carbon were investigated at a single shallow water estuarine site in trinity bay texas the uppermost lobe of galveston bay during november 2000 radio isotopes were used to estimate sediment mixing and accumulation rates and benthic chamber and pore water measurements were used to determine sediment water exchange fluxes of oxygen nutrients and metals and infer carbon oxidation rates using 7 be and 234 th xs the sediment mixing coefficient d b was 4 3 1 8 cm 2 y 1 a value that lies at the lower limit for marine environments indicating that mixing was not important in these sediments at this time sediment accumulation rates s a estimated using 137 cs and 210 pb xs were 0 16 0 02 g cm 2 y 1 the supply rate of organic carbon to the sediment water interface was 30 3 9 mmol c m 2 d 1 of which 10 or 2 9 0 44 mmol c m 2 d 1 was lost from the system through burial below the 1 cm thick surface mixed layer measured fluxes of o 2 were 26 3 8 mmol m 2 d 1 and equated to a carbon oxidation rate of 20 3 3 mmol c m 2 d 1 which is an upper limit due to the potential for oxidation of additional reduced species using organic carbon gradients in the surface mixed layer carbon oxidation was estimated at 2 6 1 1 mmol c m 2 d 1 independent estimates made using pore water concentration gradients of ammonium and c n stoichiometry equaled 2 8 0 46 mmol c m 2 d 1 the flux of doc out of the sediments doc efflux was 5 6 1 3 mmol c m 2 d 1 in general while mass balance was achieved indicating the sediments were at steady state during this time changes in environmental conditions within the bay and the surrounding area mean this conclusion might not always hold these results show that the majority of carbon oxidation occurred at the sediment water interface via o 2 reduction this likely results from the high frequency of sediment resuspension events combined with the shallow sediment mixing zone leaving anaerobic oxidants responsible for only 10 15 of the carbon oxidized in these sediments

internal tides in the northern gulf of california 1 the characteristics of the internal tide in the northern gulf of california are described using data from two moored arrays of temperature and current sensors one for summer and one for winter located between angel de la guarda island and the mainland from the summer six sensor mooring it was found that 1 the current fluctuations are dominated by the semidiurnal frequency band while the quarterdiurnal frequency dominated the temperature fluctuations 2 the baroclinic semidiurnal horizontal current fluctuations are aligned with the gulf axis and have amplitudes of 10 15 cm s 1 the vertical displacements reached 4 m in this frequency band 3 the vertical modal structure for the temperature and velocity oscillations was dominated by the first and third modes 4 the energy of the semidiurnal internal tide is 45 of that of the barotropic tide 5 vertical wave number spectra showed slightly asymmetric peaks in the high wave number components indicating that their downflowing energy is larger than that flowing upward from the winter two sensor mooring it was found that the vertical oscillations were mainly semidiurnal with root mean square amplitudes of 7 m

the hawaii to tahiti shuttle experiment the shuttle experiment conducted between hawaii and tahiti from january 1979 to june 1980 was designed to observe the changing equatorial ocean structure and circulation to study the variations and interactions of the four major equatorial ocean currents and to develop a scientific basis for their monitoring by simple observations of thermal structure and sea level preliminary analyses of the results show that the equatorial thermal structure remains intact during a normal year and that only the positions and intensities of the currents are subject to change the water transport of the equatorial undercurrent varied from 25 x 106 cubic meters per second in january to 51 x 106 cubic meters per second in july but also exhibited strong short term pulsations the equatorial surface flow responded strongly to the winds at periods of 1 month and longer an array of drifter buoys in the equatoral countercurrent was subject to very little dispersion while traveling over 4500 kilometers in 4 months low frequency fluctuations in the north equatorial countercurrent can be monitored by means of the difference in sea level between fanning and majuro

lagrangian observations of the circulation in the northern gulf of california argos drifters deployed in the northern gulf of california in september 1995 showed the presence of a cyclonic gyre while a second deployment in march 1996 revealed an anticyclonic gyre a circulation pattern consisting of a seasonally reversing gyre had been proposed before on the basis of satellite images geostrophic calculations and numerical models but so far no direct observations have been made to test its existence in september the gyre was cyclonic baroclinic very well defined stable and strong its mean speed and rotation time were 0 3 m s21 and 7 days in march the gyre had the same mean speed but it was anticyclonic and displaced to the northwest of the summer position the march gyre has barotopic and baroclinic characteristics but the observed speeds are stronger than in numerical simulations these data and a data bank analysis suggest that the summer gyre is a persistent summer feature but the winter spring situation remains ill defined and requires further research

trade wind fetch related variations in equatorial undercurrent depth speed and transport a dynamical model is developed to examine the dependence of equatorial undercurrent depth speed and volume transport on trade wind fetch the model ocean is linear continuously stratified vertically diffusive and formulated on the equatorial beta plane analytical solutions are derived in closed form for realistic choices of model parameters results indicate that the undercurrent would be significantly shallower and weaker in the atlantic than in the pacific because of the shorter atlantic trade wind fetch

the lower atmosphere over the gulf of california automated meteorological observations at coastal and island stations instrumented aircraft flights and coastal soundings were made between july 1983 and june 1985 to define the variations of the lower atmosphere over the northern half of the gulf of california during the two important climatic seasons the mid latitude winter and the subtropical summer a marine layer is well defined over water during both seasons but dissipates within a few kilometers inland the winter large scale pressure field is dominated by the great basin high over the southwestern united states modulated by upper level synoptic activity it causes 3 to 6 days events of northwesterly winds 8 12 m s 1 directed along the gulf s axis which are coherent over basin scales and bring cool dry desert air over the gulf the vertical scale of these winds is 700 1000 m over land on the western side of the gulf close to the height of the baja california mountains but only 100 400 m over water defined by the wintertime inversion cross gulf winds related to topographic effects during upper level trough passages over baja california are particularly intense in the northwestern portion of the gulf the winter marine layer is defined by a 1 to 4 5 c temperature inversion and a dew point temperature of 6 11 c a moisture content of 6 8 g kg 1 weak subsidence reduces dew point values to 4 c above the inversion winter winds above the marine layer are coherent 0 8 across the width of the gulf the summer large scale pressure field is dominated by a thermal low over the southwestern united states and drives weak 2 5 m s 1 southeasterly winds also directed primarily along the gulf which are less spatially uniform than winter winds air temperature and moisture content are rather constant and topographic effects are absent the summer marine layer is on the order of 200 300 m thick with dew point temperatures of 26 28 c 21 24 g kg 1 and capped by a weak temperature inversion 1 2 c over water aloft the dew point temperature is 17 21 c and winds are weak and uncorrelated across the width of the gulf during june and early july 1984 four week long pulses of southeasterly winds 10 m s 1 support the existence reported previously of moisture surges from the gulf into the sonoran desert a dynamical analysis of subdiurnal motions shows that the cross gulf momentum balance is geostrophic the along gulf balance is ageostrophic with the along gulf pressure gradient opposed by friction at the surface these results are consistent with a scale analysis of the equations of motion in the marine layer over the gulf of california

pore water advection and solute fluxes in permeable marine sediments ii benthic respiration at three sandy sites with different permeabilities german bight north sea this contribution presents total oxygen uptake tou rates and nutrient fluxes of organically poor permeable shelf sands of the german bight measurements have been made in situ with the novel autonomous benthic chamber system sandy under controlled conditions of advective pore water exchange average oxygen consumption rates of 31 3 18 2 mmol m 2 d 1 measured in this study were relatively high as compared with rates reported from shelf sediments with much higher organic contents tou of highly permeable medium and coarse grained sands was substantially enhanced in the presence of advection this indicates that advective oxygen supply contributed significantly to respiration in these sediments and that advection has to be considered when assessing oxygen consumption and organic matter mineralization in shelf areas in fine grained less permeable sands no effect of advection could be measured a lower advective oxygen supply in these sediments is in agreement with a release of ammonium instead of nitrate and a shallower oxygen penetration depth scaled up to the entire german bight the results imply that in 40 of the area an effect of advection on benthic oxygen uptake and other advectionrelated processes can be largely excluded while in the remaining 60 significant pore water advection potentially takes place however because permeabilities of the sediments investigated in this study were widely spaced a significant effect on oxygen supply was only verified for highly permeable sands that are likely to cover approximately 3 of the area

variability in the eastern equatorial pacific ocean during 1986 1988 we examine variability in the eastern equatorial pacific during 1986 1988 using conductivity temperature depth data velocity and temperature data from equatorial moorings between 110 w and 140 w and wind data from a basin scale zonal array of islands and moorings between 110 w and 165 e the period studied coincides with the el nino southern oscillation enso event of 1986 1987 and a subsequent cold event in 1988 weak warm sea surface temperature anomalies first appeared in the eastern equatorial pacific in mid 1986 and increased to 1 c in september november 1986 in association with a 30 cm s 1 weakening of the south equatorial current and a 20 to 40 m depression of the thermocline these warm anomalies lasted until early 1988 after which a large scale shoaling of the thermocline led to sea surface temperatures more than 3 c colder than climatology year to year fluctuations in the eastern pacific were related primarily to zonal wind variations in the central and western pacific westerly wind stress anomalies of 0 02 0 05 n m 2 were observed between 140 w and 165 e from the latter half of 1986 until the end of 1987 these were replaced by easterly wind anomalies of similar magnitude between 157 w and 165 e in 1988 energetic intraseasonal fluctuations with periods of 2 3 months were also prominent in zonal current temperature and dynamic height time series these fluctuations propagate eastward at approximately first baroclinic mode kelvin wave phase speeds and are forced west of the date line by episodes of westerly winds extrema in several oceanic variables occurred in association with these waves though their precise dynamical link to the enso cycle is unclear from our data sea surface temperature and thermocline depth anomalies at 0 110 w were less pronounced during the 1986 87 enso than during the 1982 1983 enso the equatorial undercurrent though weaker than normal in early 1987 did not disappear as it did in early 1983

bidecadal variability in the intermediate waters of the northwestern subarctic pacific and the okhotsk sea in relation to 18 6 year period nodal tidal cycle 1 on the basis of historical oceanographic data we investigated the long term variations of the intermediate waters in the four regions in the northwestern subarctic pacific oyashio okhotsk sea mode water upstream oyashio and east kamchatka current we found bidecadal oscillations in these water properties that are synchronized with the 18 6 year period nodal cycle in periods when the diurnal tide is strong the following characteristics are found apparent oxygen utilization and phosphate are low in oyashio and okhotsk sea mode water the thickness of the intermediate layers is large and thus potential vorticity is correspondingly low in oyashio okhotsk sea mode water and upstream oyashio around the mesothermal temperature maximum water isopycnal potential temperature are low in the areas on the pacific side and high in the intermediate layer of okhotsk sea mode water the mixing ratio of okhotsk sea mode water in the upstream oyashio water is high these bidecadal oscillations can be explained by changes in the vertical mixing around the kuril straits induced by the diurnal tide whose amplitude is modulated with the 18 6 year nodal cycle higher sea surface salinity water around the kuril straits caused by stronger tidal mixing is possibly transported northward along the cyclonic okhotsk sea gyre and possibly enhances the formation of the dense shelf water this makes apparent oxygen utilization phosphate and potential vorticity lower in okhotsk sea mode water and oyashio

the benthic silica cycle in the northeast atlantic annual mass balance seasonality and importance of non steady state processes for the early diagenesis of biogenic opal in deep sea sediments within the framework of the eu funded bengal programme the effects of seasonality on biogenic silica early diagenesis have been studied at the porcupine abyssal plain pap an abyssal locality located in the northeast atlantic ocean nine cruises were carried out between august 1996 and august 1998 silicic acid dsi increased downward from 46 2 to 213 m mean of 27 profiles biogenic silica bsi decreased from ca 2 near the sediment water interface to 1 at depth benthic silicic acid fluxes as measured from benthic chambers were close to those estimated from non linear dsi porewater gradients some 90 of the dissolution occurred within the top 5 5 cm of the sediment column rather than at the sediment water interface and the annual dsi efflux was close to 0 057 mol si m 2 yr 1 biogenic silica accumulation was close to 0 008 mol si m 2 yr 1 and the annual opal delivery reconstructed from sedimentary fluxes assuming steady state was 0 065 mol si m 2 yr 1 this is in good agreement with the mean annual opal flux determined from sediment trap samples averaged over the last decade 0 062 mol si m 2 yr 1 thus ca 12 of the opal flux delivered to the seafloor get preserved in the sediments a simple comparison between the sedimentation rate and the dissolution rate in the uppermost 5 5 cm of the sediment column suggests that there should be no accumulation of opal in pap sediments however by combining the bengal high sampling frequency with our experimental results on bsi dissolution we conclude that non steady state processes associated with the seasonal deposition of fresh biogenic particles may well play a fundamental role in the preservation of bsi in these sediments this comes about though the way seasonal variability affects the quality of the biogenic matter reaching the seafloor hence it influences the intrinsic dissolution properties of the opal at the seafloor and also the part played by non local mixing events by ensuring the rapid transport of bsi particles deep into the sediment to where saturation is reached

a note on why does the ballenas channel have the coldest sst in the gulf of california 1 a three dimensional nonlinear baroclinic model is used to verify the circulation in the ballenas channel gulf of california deduced from observations which concluded that the cold sst of the channel is due to the deep inflow of water over the sills at both ends of the channel this convergence at depth would lead to upwelling divergence in the upper layers and to surface outflow through both ends here it is reported that the deep flow from the south does enters into the channel but not that from the north the deep inflow returns back mainly along the surface through the same southern end of the channel and a small fraction flows out through the northern end of the channel and between angel de la guarda and san lorenzo islands the bottom flow that enters through san esteban sill does not go all the way along tiburon and delfin basins and into ballenas channel through the northern sill instead it returns in the intermediate and surface layers after mixing in those basins

sediment community oxygen consumption in the deep gulf of mexico sediment community oxygen consumption scoc has been measured from the continental shelf out to the sigsbee abyssal plain in the ne gulf of mexico gom scoc rates on the continental shelf were an order of magnitude higher than those on the adjacent continental slope 450 2750 m depth and two orders of magnitude higher than those on the abyssal plain at depths of 3 4 3 65 km oxygen penetration depth into the sediment was inversely correlated with scoc measured within incubation chambers but rates of scoc calculated from either the gradient of the o2 profiles or the total oxygen penetration depth were generally lower than those derived from chamber incubations scoc rates seaward of the continental shelf were lower than at equivalent depths on most continental margins where similar studies have been conducted and this is presumed to be related to the relatively low rates of pelagic production in the gom the scoc however was considerably higher than the input of organic detritus from the surface water plankton estimated from surface water pigment concentrations suggesting that a significant fraction of the organic matter nourishing the deep gom biota is imported laterally down slope from the continental margin

early stage soliton observations in the sulu sea abstractobservations of early stage large amplitude nonlinear internal waves in the sulu sea are presented water column displacement and velocity profile time series show the passage of two solitary like waves close to their generation site additional observations of the same waves are made as they propagate through the sulu sea basin these waves of depression have an estimated maximum amplitude of 44 m observed wave amplitude and background stratification are used to estimate parameters for both a korteweg de vries k dv and a joseph wave solution these analytic model solutions are compared with a fully nonlinear model as well model wave half widths bracket the observed wave with the joseph model narrower than the k dv model the modal structure of the waves change as they transit northward though the sulu sea with higher mode features present in the southern sulu sea which dissipate by the time the waves reach the north observed and modeled energies are roughly comparable with observed pot

sill processes related to deep water renewal in a fjord observations of the gravitational circulation over the sill at the entrance to puget sound indicate a fortnightly modulation of the two layer flow with a corresponding variation in stratification gravitational circulation and stratification reach a maximum during neap tides and a minimum during spring tides the modulation appears to be a function of the turbulence generation by tidal flow over the sill which varies as a function of tidal amplitude the enhanced gravitational circulation during neap tides augments the flux of dense water across the sill region and episodes of bottom water renewal in puget sound result intrusions of dense water in the main basin of the sound show a fortnightly periodicity with a phase lag appropriate for the propagation of an internal bore from the sill region commencing at the neap tide observations indicate that the intrusions take the form of gravity currents propagating at approximately 20 cm s 1 down the main basin the detailed dynamics of the turbulent mixing processes that modulate the onset of inflow were not resolved in this study but the integrated effect of tidal mixing on the low frequency circulation is clearly demonstrated

empirical orthogonal function analysis of sea surface temperature patterns in delaware bay empirical orthogonal functions eofs are used to study a time series of ir images from the delaware bay region to determine the dominant patterns of sea surface temperature sst variance thirty two months of avhrr imagery from february 1992 to september 1994 were used in the study the sst images were averaged into monthly means for the analysis eof analysis decomposed the time series into its component parts for delaware bay the seasonal solar heating cycle dominated the results accounting for 95 3 of the total variance higher modes in this area are interpreted as the result of spring heating and fall cooling of shallow river and bay waters ahead of offshore waters the eof results provide independent satellite derived evidence for lateral variability in the circulation of the estuary which had previously been found in in situ studies the lateral variability in the bay circulation is a result of delaware bay s drowned river valley bathymetry

an interhemispheric tropical sea level seesaw due to el nino taimasa abstractduring strong el nino events sea level drops around some tropical western pacific islands by up to 20 30 cm such events referred to as taimasa in samoa expose shallow reefs thereby causing severe damage to associated coral ecosystems and contributing to the formation of microatolls during the termination of strong el nino events a southward movement of weak trade winds and the development of an anomalous anticyclone in the philippine sea are shown to force an interhemispheric sea level seesaw in the tropical pacific that enhances and prolongs extreme low sea levels in the southwestern pacific spectral features in addition to wind forced linear shallow water ocean model experiments identify a nonlinear interaction between el nino and the annual cycle as the main cause of these sea level anomalies

an analysis of errors in sea surface temperature in a series of infrared images from noaa 6 as part of the coastal ocean dynamics experiment 58 infrared satellite images were analyzed for the magnitude and source of their errors in predicting sea surface temperature comparisons with near surface thermistors on moorings and differences between images from consecutive days showed that a two channel atmospheric correction using the 3 7 m and the 11 m channels was ineffective in reducing errors large systematic errors which have the form of a constant over an image were found in both channels a simple viewing angle correction reduced fluctuations in the area mean 11 m channel temperature from 0 74 to 0 45 c a satisfactory correction could not be found for the larger fluctuations in the 3 7 m channel which appears to be degraded by reflected or scattered solar radiation by taking account of the known dependence of atmospheric effects on viewing angle geometry it was possible to isolate the primary causes of error to estimate typical magnitudes and to correct for them the 11 m channel temperature error from the northern california atmosphere was found to be nearly constant in time over a 100 day period but to vary slowly with distance from the coast

mass transfer from smooth alabaster surfaces in turbulent flows the mass transfer velocity for alabaster plates in smooth wall turbulent flow is found to vary with the friction velocity according to an analytic solution of the advective diffusion equation deployment of alabaster plates on the sea floor can perhaps be used to estimate the viscous stress and transfer velocities for other species

extraction of pore water from marine sediments a review of possible artifacts with pertinent examples from the north atlantic abstract great care must be taken in extracting pore water if results are to be reliable errors can arise by inadequate storage conditions prior to pore water extraction by a difference between extraction temperature and the in situ temperature by oxygen contamination and possibly by high squeezing pressures three different extraction methods have been applied to samples from 30 m long piston cores collected in two abyssal plains in the north atlantic ocean the results demonstrate that all of the above mentioned errors have occurred these errors are discussed ad examples are shown

measurements of diffusivity near the sediment water interface with a fine scale resistivity probe fine scale profiles of the sedimentary formation factor f were obtained from measurements of resistivity at millimetre intervals in marine sediments these profiles demonstrated that rapid decreases in diffusivity occurred in the upper few centimeters of both compact intertidal sands and fine silty muds in the compact sands a 70 decrease in the formation factor was observed within 2 cm of the interface close correlations were found between the formation factor and sediment porosity for both sediment types profiles of 1f predicted from these correlations and porosity profiles were very similar to those obtained from measurements of resistivity these correlations also suggested that 3 is a better approximation of the formation factor in fine muds than the archie relation 2 in both sediments the interfacial value of the diffusion coefficient was estimated to be between 74 and 87 of its value in free solution a value much higher than is normally assumed

water mass formation in the gulf of california the gulf of california is a long narrow marginal sea lying between the baja california peninsula and the mainland of mexico air sea fluxes of heat and moisture in the gulf are enhanced because of geographical isolation from the pacific provided by the mountainous baja california peninsula in the northern gulf annual evaporation rates are about 1 m y 1 unlike most evaporative basins however the gulf gains heat from the atmosphere at an annual average rate of 20 to 80 w m 2 bray 1988 given the unusual air sea forcing of the gulf what form or forms should water mass formation take the annual moisture loss and heat gain require that high salinity surface water be transported downward to an intermediate depth and that cold fresh inflow be transported upward to an intermediate depth this is accomplished through several mechanisms 1 winter convection this occurs only in a limited geographical region the wagner basin of the far northern gulf except in el nino southern oscillation years when convection appears to be more widespread 2 dispersion of convected water in small eddylike features this occurs within a large scale southward transport possibly driven by the large scale density gradient associated with atmospheric fluxes 3 an anticyclonic circulation in the northern gulf this is found south of the convection region and transports high salinity water off the shallow shelves and to substantial depths where it may mix with water of central gulf origin 4 tidal mixing most of the energy available for mixing in the northern gulf derives from the tides in particular tidal mixing over the sill in the island region is responsible for the substantial reduction in salinity of northern gulf waters as they enter the central gulf

shelf circulation in the gulf of california a description of the variability the first long term measurements 1983 1984 of winds temperature bottom pressure and currents made in the gulf of california are used to describe the dynamically important spatial and temporal scales and to compare and contrast the shelf circulation on opposite sides of the guaymas basin in addition a qualitative assessment of possible forcing mechanisms of gulf shelf circulation and an account of an energetic coastal trapped wave event are presented winds over the gulf are weak and variable with maximum wind speeds of 10 15 m s and sustained wind events of less than a week low frequency 3 cpd fluctuations in the dominant along gulf component of the wind field which are largely coherent over the study area are directed upgulf during summer and downgulf for the remainder of the year low frequency winds are not significantly correlated 95 confidence level with currents temperature and pressure in part because of weak local winds and nonlocally forced coastal trapped waves on longer time scales seasonal upwelling on both sides of the gulf and guaymas basin mean currents are related to local winds low frequency current fluctuations on the two facing shelf regions guaymas on the mexican mainland and santa rosalia on the baja california peninsula are not significantly correlated along gulf currents in the basin however are negatively correlated with alongshelf currents at guaymas 0 54 due to sporadically occurring eddylike features and santa rosalia 0 61 due to seasonal flow patterns low frequency fluctuations on the mainland shelf are significantly correlated during the summer e g 0 67 in temperature between topolobampo and guaymas separation of 375 km such that topolobampo leads guaymas by approximately 1 5 days this lagged signal is associated with coastal trapped waves that are generated by tropical storms and hurricanes south of the gulf and propagate poleward along the mainland shelf at speeds of 200 250 km day near guaymas current speeds of approximately 50 cm s were measured at the 100 m isobath on the mainland shelf during an event with a 20 cm coastal sea level rise the offshore decay of these waves is of the order of 50 km on the guaymas shelf low frequency temperature or equivalently density and sea level fluctuations are correlated 0 78 such that a 10 cm rise in sea level corresponds to a 20 m drop in isotherm depths over much of the water column this sea surface isotherm relationship is such that the amplitude of pressure fluctuations decays rapidly with depth e folding scale 160 m a similar relationship is only weakly apparent correlation 0 39 on the santa rosalia shelf cross gulf geostrophy is observed with 35 of the along gulf current averaged across the gulf related to dp dx measured between guaymas and santa rosalia on the guaymas and santa rosalia shelves dp dx measured across each shelf explains approximately 20 of the variability in alongshelf currents in the alongshelf momentum balance dp dy accounts for approximately 40 of the low frequency variability in dv dt at the guaymas shelf break consistent with the dynamics of freely propagating coastal trapped waves the same balance is only weakly apparent 10 of variance explained at santa rosalia at higher frequencies temperature fluctuations at guaymas are coherent and in phase to 200 m depth coherent 0 74 with the alongshelf near surface current at the shelf break m8 and exhibit a spring neap modulation consistent with internal tides

satellite derived sea surface temperature variability off california during the upwelling season abstract an empirical orthogonal function analysis of an advanced very high resolution radiometer sea surface temperature data set encompassing the spring summer period during 1991 1993 was used to examine patterns of temperature variability off northern and central california this analysis decomposed the spatial variability of remotely sensed sea surface temperature in 124 images that covered an offshore distance of 200 km and an alongshore distance of 500 km the first mode empirical orthogonal function described 65 of the spatial variability in the data set the spatial amplitude pattern of the first mode which closely resembled the mean of all the images revealed a strong cross shore gradient with much cooler water nearshore and warmer water offshore these areas of cool waters were associated with known upwelling locales and the large scale temperature structure compared favorably to that derived from historical california cooperative oceanographic fisheries investigation calcofi climatology the mode 1 temporal amplitude function representing the temporal modulation of this spatial pattern was coupled with changes in the alongshore component of the coastal wind field interannual variations in the timing of the spring transition were reflected in this temporal amplitude time series the second mode empirical orthogonal function described 11 of the variability in the data set the spatial pattern revealed a north south structure that appeared to be related to regional spatial variations in the strength of upwelling favorable wind the third empirical orthogonal function described only 3 of the data variability and the spatial structure suggested a meandering of the coastal surface flow the results of this investigation indicate that the empirical orthogonal function method was effective at characterizing from the satellite data the dominant nearshore surface properties of the california current system related to upwelling and wind and by extension suggest that it is a suitable approach for remotely investigating other less well known eastern boundary current systems

decadal climate variability is there a tidal connection abstract a possible connection between oceanic tides and climate variability arises from modulations in tidally induced vertical mixing the idea is reexamined here with emphasis on near decadal time scales occasional extreme tides caused by unusually favorable alignments of the moon and sun are unlikely to influence decadal climate since these tides are of short duration and in fact are barely larger than the typical spring tide near lunar perigee the argument by keeling and whorf in favor of extreme tides is further handicapped by an insufficiently precise catalog of extreme tides a more plausible connection between tides and near decadal climate is through harmonic beating of nearby tidal spectral lines the 18 6 yr modulation of diurnal tides is the most likely to be detectable possible evidence for this is reviewed some of the most promising candidates rely on temperature data in the vicinity of the north pacific ocean where diurnal tides are large but definitive detection is hindered by t

hindcast forecast of enso events based upon the redistribution of observed and model heat content in the western tropical pacific 1964 86 anomalous sea level anomalous observed dynamic height 0 400 db and anomalous model dynamic height are examined at the locations of 13 island sea level stations in the tropical pacific for each bimonth of the four year period 1979 to 1982 starting in 1981 the anomalous dynamic height data show off equatorial rossby waves propagated toward the w boundary of the pacific basin at the w boundary the model rossby wave activity was found to have excited coastally trapped kelvin munk waves which transmitted the anomalous dynamic height equatorward at the equator coastally trapped wave activity excited eastward propagating equatorial kelvin waves yielding a pair of anomalous peaks in dynamic height variability in the e equatorial pacific associated with the 1982 1983 enso event the evolution of the peaks in dynamic height associated with the rossby and kelvin wave activity reflects the redistribution of observed upper ocean heat content in the w tropical pacific providing a qualitative hindcast for the 1982 1983 enso event

mineralization pathways in lake sediments with different oxygen and organic carbon supply the intensity and pathways of mineralization of sedimentary organic matter were investigated in eutrophic lake zug switzerland in a depth transect 25 180 m from oxic to anoxic bottom water we recorded in situ sediment pore water concentration profiles of o2 n o and nh z with a benthic lander system equipped with both oxygen and ion selective electrodes anaerobic sedimentary mineralization ranged from 13 1 to 34 9 mmol carbon c m22 d21 and increased linearly with water depth as determined from the nh z flux rates in the anoxic pore water and the molar c nitrogen n ratio of the surface sediment a parallel increase of the total organic carbon concentration of the sediment was attributed to lateral transfer of resuspended sedimentary matter denitrification was estimated from nitrate profiles and contributed only 1 5 3 2 to the total organic carbon mineralization at any water depth aerobic respiration and oxidation of reduced compounds were calculated from o2 microprofiles and pore water data of dissolved mn ii fe ii s ii and ch4 when the o2 concentration exceeded 0 15 mmol l 21 in the sediment overlying water 41 58 or 12 4 18 1 mmol c m 22 d 21 was mineralized aerobically whereas at lower concentrations 0 04 mmol l21 92 of organic carbon was mineralized anaerobically total benthic mineralization of organic carbon was 26 9 34 9 mmol c m22 d21 a budget including particulate as well as dissolved reduced compounds in the sediment indicated that 95 of the anaerobic mineralization was due to methanogenesis oxidation of ch4 consumed 39 56 of the o2 at the sediment water interface oxygen exposure times for these sediments were estimated to be on the order of weeks to months these time spans are too short to change the reactivity spectrum of sedimentary organic matter

observations of the coastal upwelling region near 34 30 n of california spring 1981 abstract coordinated meteorological and oceanographic ctd measurements were made near point conception california during march april 1981 the goal of the observations was to study coastal upwelling and the local characteristics of the assumed wind driving results showed substantial topographically induced spatial structure in the near surface winds with weaker winds generally occurring within the santa barbara channel the 1981 spring transition event was monitored by mews of hydrographic and sea level measurements the details of the event suggest that it was not entirely driven by lead wind stress the mean sea surface temperature pattern suggests the existence of an upwelling center between points arguello and conception the individual sea surface temperature charts are all dominated by patchiness on a scale of 5 15 km the nature of these structures is not well understood but on the one occasion when a patch was isolated by a ctd survey its structure penetrated to at 1east 50 db

the slope of sea level along the equator during the 1982 1983 el nino observed deviations of monthly mean sea level at seven island stations along the equator in the pacific have been superimposed on the mean dynamic topography to determine the variations of the east west slope of sea surface topography during the 1982 1983 el nino the normal east west slope is eliminated in january 1983 when the bulk of warm water flowing eastward has reached the coast of south america the sea surface remains essentially flat from january to june 1983 although zonal winds are very weak until april only the slope requires several months to be reestablished and in october and november sea level along the entire equator is 10 cm or more below normal indicating a net loss of warm water from the equatorial pacific

the sulu sea internal soliton experiment abstract we present the results of a comprehensive study of large amplitude internal solitons generated in the sulu sea in the philippines by intense tidal flow over a sharp bathymetric feature surface signatures of these waves have been observed in images from the dmsp landsat and nimbus 7 satellites and the space shuttle sir a synthetic aperture radar a two week experiment was conducted in the sulu sea in may 1980 from r v oceanograher during which a three mooring phased array of current meters and thermistors was implanted near the wave source and at 82 km and 200 km from the source seventeen soliton packets were observed whose properties underwent significant change as they propagated across the sea vertical profiles of density temperature and acoustic backscatter as well as radar and photographic surface signatures were obtained from the ship data from satellites moorings and the ship give unprecedented information on the spatial and temporal characteristics of solitary waves which ha

estimates of the resistance to chemical transport posed by the deep sea boundary layer1 2 a strategy has been developed to permit the in situ calibration of measurements made with benthic chambers of chemical fluxes across the sediment water interface the resistance to chemical transport posed by the boundary layer is estimated using chemical transport techniques in benthic flux chamber mock ups and on the sea floor dissolution from gypsum alabaster plates is measured both inside and outside the flux chambers cacoo dissolution and radioisotope uptake techniques are suitable for laboratory and deep sea calibration of benthic fluxes broadly concordant resistance estimates have been achieved within flux chambers with these three quite different approaches an estimate of 470 p for the equivalent stagnant boundary film thickness has been made by the alabaster method on the sea floor at manop site h in the eastern pacific the transport of mn2 from the bottom waters to site h nodules if controlled by diffusion through a film of this thickness would be sufficient to explain their growth rates