Honjo Susumu

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Comparison of Niskin vs. in situ approaches for analysis of gene expression in deep Mediterranean Sea water samples

( 2014-10) Edgcomb, Virginia P. ; Taylor, Craig D. ; Pachiadaki, Maria G. ; Honjo, Susumu ; Engstrom, Ivory B. ; Yakimov, Michail M.

Obtaining an accurate picture of microbial processes occurring in situ is essential for our understanding of marine biogeochemical cycles of global importance. Water samples are typically collected at depth and returned to the sea surface for processing and downstream experiments. Metatranscriptome analysis is one powerful approach for investigating metabolic activities of microorganisms in their habitat and which can be informative for determining responses of microbiota to disturbances such as the Deepwater Horizon oil spill. For studies of microbial processes occurring in the deep sea, however, sample handling, pressure, and other changes during sample recovery can subject microorganisms to physiological changes that alter the expression profile of labile messenger RNA. Here we report a comparison of gene expression profiles for whole microbial communities in a bathypelagic water column sample collected in the Eastern Mediterranean Sea using Niskin bottle sample collection and a new water column sampler for studies of marine microbial ecology, the Microbial Sampler – In Situ Incubation Device (MS-SID). For some taxa, gene expression profiles from samples collected and preserved 33 in situ were significantly different from potentially more stressful Niskin sampling and 34 preservation on deck. Some categories of transcribed genes also appear to be affected by sample 35 handling more than others. This suggests that for future studies of marine microbial ecology, 36 particularly targeting deep sea samples, an in situ sample collection and preservation approach 37 should be considered.
The Arctic Environmental Drifting Buoy (AEDB) : report of field operations and results, August, 1987 - April 1988

(Woods Hole Oceanographic Institution, 1990-01) Honjo, Susumu ; Krishfield, Richard A. ; Plueddemann, Albert J.

There are strong reasons to gather data on polar oceanogrphy and climatology in real time using fully automated, unattended instrumentation systems for long periods; particularly during the inaccessible winter months when moving ice is extremely hazardous. We deployed an Artic Environmental Drifting Buoy (AEDB) on 4 August 1987 at 86°7'N, 22°3'E off of the FS Polarstern on a large 3.7 m thick ice island. The AEDB consisted of 2 major components: a 147 cm diameter surface float housing ARGOS transmitters and a data logger for ice-profiling thermistors, and a 125 m long mooring line attached to the sphere and fed though a 1m diameter ice hole. Along the mooring were deployed 2 fluorometers, conductivity and temperature loggers, an Acoustic Doppler Current Profiler (ADCP), a current meter, and a time-series sediment trap/micro-filter pump/transmissometer unit. The AEDB proceeded southwesterly with the Transpolar Drift at an average speed of 15.3 km/day, with a maximum speed of 88.8 km/day. On 2 January 1988, the AEDB dropped into the water while passing through the Fram Strait and for the remaining drift period was either free-floating on the water surface or underneath the sea ice. Throughout this period, the transmitters onboard successfully transmitted position, temperature, and strain caused by ice on the sphere. Although the sediment trap package was lost during the drift, valuable data was collected by the other instruments throughout the experiment. The ice thermistor data was used to determine oceanic heat flux, while continuous ADCP observations over the Yermak Plateau provided a wealth of information for understanding internal waves in the ice-covered ocean. The buoy was recovered by the Icelandic ship R/S Arni Fridriksson on 15 April 1988 at 65°17'N, 31°38'W, off southeatern Greenland, completing 3,900km of drift in 255 days. We are in the process of constructing the next automated stations which are planned for deployment in both the north and south polar regions in 1991-92.
Lateral organic carbon supply to the deep Canada Basin

(American Geophysical Union, 2008-06-12) Hwang, Jeomshik ; Eglinton, Timothy I. ; Krishfield, Richard A. ; Manganini, Steven J. ; Honjo, Susumu

Understanding the processes driving the carbon cycle in the Arctic Ocean is important for assessing the impacts of the predicted rapid and amplified climate change in this region. We analyzed settling particle samples intercepted by a time-series sediment trap deployed in the abyssal Canada Basin (at 3067 m) in order to examine carbon export to the deep Arctic Ocean. Strikingly old radiocarbon ages (apparent mean 14C age = ∼1900 years) of the organic carbon, abundant lithogenic material (∼80%), and mass flux variations temporally decoupled from the cycle of primary productivity in overlying surface waters together suggest that, unlike other ocean basins, the majority of the particulate organic carbon entering the deep Canada Basin is supplied from the surrounding margins.
Construction of Parflux Mark II sediment trap : engineering report

(Woods Hole Oceanographic Institution, 1979-11) Honjo, Susumu ; Connell, John F.

A large, open ocean applicable sediment trap has been developed at the Woods Hole Oceanographic Institution in order to assess the fluxes of particles sinking through the deep water column, under the sponsorship of the National Science Foundation. PARFLUX Mark II trap, 1978-79 version for PARFLUX phase 1 program, has been successfully developed and has gathered much meaningful data. A trap opening is 1.5 m2 and consists of 94 hexagonal buffer cells with the nominal form ratio of 2. Sediment particles are concentrated to the receiving cup located at the bottom of the funnel-shaped trap. Two types of receiving cups have been developed; a trap with Type S cup is open at both ends as it sinks to the designated depth. Twenty-four hours after the deployment the receiving cup moves into alignment with the funnel to store the sediment. At the end of deployment a spring mechanism activated by a quartz oscillator based electrical timer-release retracts the receiving cup, seals the collected sample and leave the funnel open at both ends while the trap ascends for recovery. Type C mechanism is installed with a shutter which seals the cup during recovery; this type involves a simple mechanism with less moving parts. Sodium azide/sodium chloride solution is diffused through a series of membrane filters to keep the cup contents in an aseptic condition. Since October 1976 to December 1979, we have deployed and recovered 24 traps successfully along with several moorings as deep as 5,600 m for as long as 112 days. This reports the engineering detail and lists the required parts to assist the construction, operation and maintenance of the PARFLUX Mark II sediment trap.
Particle fluxes, south central Black Sea : 1982-1985

(Woods Hole Oceanographic Institution, 1987-05) Honjo, Susumu ; Manganini, Steven J. ; Asper, Vernon L. ; Hay, Bernward J. ; Karowe, Amy

Annual particle fluxes were measured by sediment traps deployed at a station about 40 km north of Amasra, Southern Black Sea, by an international team of oceanographers from Germany, Turkey, and the United States. This experiment continuously monitored oceanic particle flux for two and a half years from October 28, 1982 to April 6, 1985 at approximately two-week intervals at 250 m and 1200 m below the surface using 1.2 m2 Mark 5-12 time-series sediment traps. The water depth at this station was about 2,200 m and both traps were situated within the anoxic layer of the Black Sea. The collected flux samples were analyzed at the Woods Hole Oceanographic Institution to document the basic sedimentary characteristics using a quarter of each sample split. In the first data file from this experiment, total mass, carbonate, noncombustible, combustible, opal (biogenic silica), organic carbon, and organic nitrogen fluxes data are presented in bar graphs and detailed tables, in unit samples covering a two-week period at each depth. The Black Sea Sedimentation Data File is intended to provide source data on particle fluxes from this unique ocean environment for further investigation and for planning advanced research programs.
Cruise report: JGOFS Leg I International study of the North Atlantic Bloom : R/V Atlantis II Voyage 119.2, Funchal to Reykjavik, March/April 1989

(Woods Hole Oceanographic Institution, 1989-07) Honjo, Susumu ; Manganini, Steven J. ; Krishfield, Richard A.

With the support of the National Science Foundation, we have completed the first cruise devoted to the GOFS and JGOFS program for the North Atlantic Bloom studies between March 28 and April 6 on board R/V Atlantis II. The major task of this cruise, to deploy bottom-tethered mooring arrays with time-series sediment traps along with current meters at two critical stations, 34°N and 47°N along 20°W, was accomplished. All 6 sediment traps, 3 on each array, were set at 14-day intervals for 13 periods from April 3 to September 26, 1989. Their opening and closing times were synchronized throughout the period of deployment. The arrays and instruments will be recovered and redeployed in September/October, 1989. Ancillary water column data, such as CTD, fluorometry, pigments, and major nutrient distribution, were also successfully completed (except for transmissometry profiling at the 47°N station) in order to understand the prebloom setting at JGOFS 34°N, 47°N, and 60°N stations. At the 47°N station on April 2, the mixed layer depth was 248m.
Ice-Ocean Environmental Buoys (IOEB) : technology and deployment in 1991-1992

(Woods Hole Oceanographic Institution, 1993-10) Krishfield, Richard A. ; Doherty, Kenneth W. ; Honjo, Susumu

Based upon the 1987-88 Arctic Environmental Drifting Buoy (AEDB), the Ice-Ocean Environmental Buoy (IOEB) was developed to acquire and telemeter in near real-time inter-relatable time-series data on atmospheric, oceanographic and ice physics in ice-covered oceans during all seasons. Two IOEBs were successfully deployed in two Arctic Sea Basin Stations in April, 1992. Since then, although some sensors malfunctioned, for 18 continuous months, they have been sending massive amounts of information. In this report we describe the technology which was developed for the 1991 IOEB. Mechanically, the IOEB consists of an extremely durable surface flotation package and an underwater mooring line of instruments and sensors. The apex contains data loggers for air, ice and engineering measurements, microcontroller modules for accumulating the data from all the instruments, and ARGOS platform transmit terminals (PTTs) for broadcasting the data. Extending above the surface float, a mast supports a wind monitor and air temperature probe, which along with a barometer provides meteorological data. Thermistor strings, vibrating wire stress sensors, and a thickness gauge are installed in the ice surrounding the buoy, and are interrogated by the modules inside the apex. In the ocean, 110m of conducting strength cable passes the data from conductivity/temperature recorders, an Acoustic Doppler Current Profier and data compression module, a dissolved oxygen sensor, a transmissometer and fluorometers to the PTT microcontrollers. Furthermore, a suspended particle collector and sediment trap transmit status information along the two-wire multidrop network cable. Because the IOEB differs from the AEDB by telemetering the majority of the scientific data, a complicated compression scheme is incorporated to broadcast the data from the 103 variables within the allowable 256-bit ARGOS data stream. Via Service ARGOS, this data currently becomes available to scientists in several countries within eight hours of transmission. In April 1992, two IOEBs were deployed at separate ice camps in the Arctic Ocean with battery power adequate to sustain the systems for over two years. One was deployed 115 miles from the North Pole in the center of the Transpolar Drift sea-ice current, and the other off of the coast of Alaska along the edge of the Beaufort Gyre. Airplanes capable of landing on ice were used for the transportation of the systems to their final destination. Simultaneously, a third, reduced version of the IOEB was deployed in the Weddell Sea by the Scott Polar Research Institute.
Autonomous Microbial Sampler (AMS), a device for the uncontaminated collection of multiple microbial samples from submarine hydrothermal vents and other aquatic environments

( 2006-01-11) Taylor, Craig D. ; Doherty, Kenneth W. ; Molyneaux, Stephen J. ; Morrison, Archie T. ; Billings, John D. ; Engstrom, Ivory B. ; Pfitsch, Don W. ; Honjo, Susumu

An Autonomous Microbial Sampler (AMS) is described that will obtain uncontaminated and exogenous DNA-free microbial samples from most marine, fresh water and hydrothermal ecosystems. Sampling with the AMS may be conducted using manned submersibles, Remotely Operated Vehicles (ROVs), Autonomous Underwater Vehicles (AUVs), or when tethered to a hydrowire during hydrocast operations on research vessels. The modular device consists of a titanium nozzle for sampling in potentially hot environments (>350°C) and fluid-handling components for the collection of six independent filtered or unfiltered samples. An onboard microcomputer permits sampling to be controlled by the investigator, by external devices (e.g., AUV computer), or by internal programming. Temperature, volume pumped and other parameters are recorded during sampling. Complete protection of samples from microbial contamination was observed in tests simulating deployment of the AMS in coastal seawater, where the sampling nozzle was exposed to seawater containing 1x106 cells ml-1 of a red pigmented tracer organism, Serratia marinorubra. Field testing of the AMS at a hydrothermal vent field was successfully undertaken in 2000. Results of DNA destruction studies have revealed that exposure of samples of the Eukaryote Euglena and the bacterium S. marinorubra to 0.5 N sulfuric acid at 23°C for 1 hour was sufficient to remove Polymerase Chain Reaction (PCR) amplifiable DNA. Studies assessing the suitability of hydrogen peroxide as a sterilizing and DNA-destroying agent showed that 20 or 30% hydrogen peroxide sterilized samples of Serratia in 1 hr and destroyed the DNA of Serratia, in 3 hrs, but not 1 or 2 hrs. DNA AWAY™ killed Serratia and destroyed the DNA of both Serratia and the vent microbe (GB-D) of the genus Pyrococcus in 1 hour.
Biogenic particle fluxes at the 34°N 21°W and 48°N 21°W stations, 1989-1990 : methods and analytical data compilation

(Woods Hole Oceanographic Institution, 1992-03) Honjo, Susumu ; Manganini, Steven J.

This technical report presents the results of analyses on opal, organic carbon, nitrogen and phosphorus content in each of 156 specimen samples collected from the moored sediment trap experiment that was a part of JGOFS North Atlantic Bloom Experiment. The analyzed samples represent a spatio-temporal matrix formed by 6 time-series sediment traps that provided 26 periods of uniform and synchronized periods of 14 days, except for one longer and one shorter period. Traps were deployed at 3 depths, 1 km, 2 km and 0.7 km above the bottom, and at 2 stations, 34°N 21°W and 48°N 21°W from April 4, 1989 to April 17, 1990, as shown in Tables 1 and 2. There was an 20-day hiatus in September /October 1989 for changeover of the trap moorings. Some samples were unusable because of the in trusion of fish. Samples were separated into several aliquots by wet-splitting, then water sieved into larger-than- and smaller-than-1-mm sizes. The fluxes of biogeochemical elements and constituents were determined on these aliquots and size fractions for: carbonate by vacuum gasometric method; opal by selective leaching method; reactive phosphorus by high temperature oxidation hydrolysis method; and organic carbon and nitrogen by applying an elementary analyzer. The annual fluxes, fluxes during the bloom, pre- and post-bloom episodes were normalized to a 365-day calendar year (Table 6) and are summarized in Tables 7 to 12. Variabilty of particle fluxes by each period at the two stations in terms of size fractions, sedimentary constituents and elements are shown in Tables 13 and 14. The molar ratios between pairs of critical biogeochemical elements during each episode and annually, shown at various depths and stations, are included in Tables 10 through 14.
Storm-driven mixing and potential impact on the Arctic Ocean

(American Geophysical Union, 2004-04-09) Yang, Jiayan ; Comiso, Josefino C. ; Walsh, David ; Krishfield, Richard A. ; Honjo, Susumu

Observations of the ocean, atmosphere, and ice made by Ice-Ocean Environmental Buoys indicate that mixing events reaching the depth of the halocline have occurred in various regions in the Arctic Ocean. Our analysis suggests that these mixing events were mechanically forced by intense storms moving across the buoy sites. In this study, we analyzed these mixing events in the context of storm developments that occurred in the Beaufort Sea and in the general area just north of Fram Strait, two areas with quite different hydrographic structures. The Beaufort Sea is strongly influenced by inflow of Pacific water through Bering Strait, while the area north of Fram Strait is directly affected by the inflow of warm and salty North Atlantic water. Our analyses of the basin-wide evolution of the surface pressure and geostrophic wind fields indicate that the characteristics of the storms could be very different. The buoy-observed mixing occurred only in the spring and winter seasons when the stratification was relatively weak. This indicates the importance of stratification, although the mixing itself was mechanically driven. We also analyze the distribution of storms, both the long-term climatology and the patterns for each year in the past 2 decades. The frequency of storms is also shown to be correlated (but not strongly) to Arctic Oscillation indices. This study indicates that the formation of new ice that leads to brine rejection is unlikely the mechanism that results in the type of mixing that could overturn the halocline. On the other hand, synoptic-scale storms can force mixing deep enough to the halocline and thermocline layer. Despite a very stable stratification associated with the Arctic halocline, the warm subsurface thermocline water is not always insulated from the mixed layer.
Detection of change in the Arctic using satellite and in situ data

(American Geophysical Union, 2003-12-24) Comiso, Josefino C. ; Yang, Jiayan ; Honjo, Susumu ; Krishfield, Richard A.

The decade of the 1990s was the warmest decade of the last century, while the year 1998 was the warmest year ever observed by modern techniques, with 9 out of 12 months of the year being the warmest months. Satellite ice cover and surface temperature data, European Centre for Medium-Range Weather Forecasts (wind), and ocean hydrographic data are examined to gain insights into this warming phenomenon. Areas of ice-free water in both western and eastern regions of the Arctic are found to have followed a cyclical pattern with approximately decadal period but with a lag of about 3 years between the eastern and western regions. The pattern was interrupted by unusually large anomalies in 1993 and 1998 in the western region and in 1995 in the eastern region. The area of open water in 1998 was the largest ever observed in the western region and occurred concurrently with large surface temperature anomalies in the area and adjacent regions. This also occurred at a time when the atmospheric circulation changed from predominantly cyclonic in 1996 to anticyclonic in 1997 and 1998. Detailed hydrographic measurements over the same general area in April 1996 and April 1997 indicate a warming and significant freshening in the top layer of the ocean, suggesting increases in ice melt and/or river runoff. Continuous ocean temperature and salinity data from ocean buoys at depths of 8, 45, and 75 m confirm these results and show large interannual changes during the 1996–1998 period. Surface temperature data show a general warming in the region that is highly correlated with observed decline in summer sea ice, while hydrographic data suggest that in 1997 and 1998, the upper part of the ocean was unusually fresh and warm compared to available data between 1956 and 1996.
Ice-ocean environmental buoy program : archived data processing and graphical results from April 1992 through November 1998

(Woods Hole Oceanographic Institution, 1999-08) Krishfield, Richard A. ; Honjo, Susumu ; Takizawa, Takatoshi ; Hatakeyama, Kiyoshi

Between 1992 and 1998, three Ice-Ocean Environmental Buoys (IOEBs) were deployed a total of six times on multiyear pack ice in the Arctic Ocean. The processing scheme for the telemetered environmental data, as well as the individual IOEBs and field operations, are described, and the processed data are presented in graphical form. The IOEB Archived Data Processing (IADP) processing scheme was conceived specifically to remove noise in data telemetered from IOEBs caused by errors in network or satellite communications, and to calibrate to absolute values. The location data consists of Argos quality 2 or 3 positions from each platform transmit terminal (PTT) on a particular IOEB, which are subsequently screened, interpolated, and combined with similarly processed locations from the other PTT, and further smoothed with a 6-hr triangular filter to produce an hourly timeseries with a standard error estimated to be -150 m. The sensor data is prefiltered, combined, adjusted for buoy drift, and screened with a Gaussian first difference filter to produce unevenly spaced timeseries of each variable measured by the IOEB. Every variable is output to a unique file per year, per buoy consisting of a two-column ACSII timeseries. Drift and sensor data are presented from the 1992 Transpolar Drift IOEB which operated for only 4 months, IOEB-1 which drifted with the Beaufort Gyre in a large anticyclonic circle from April 1992 to November 1998, and IOEB-2 which drifted through the Fram Strait in 9 months in 1994, and 1997-98 was redeployed concurrently with SHEBA at a distance 50 km from the main camp.
Fractionation of 226Ra and Ba in the upper North Pacific Ocean

(Frontiers Media, 2022-07-15) van Beek, Pieter ; Francois, Roger ; Honda, Makio C. ; Charette, Matthew A. ; Reyss, Jean-Louis ; Ganeshram, Raja S. ; Monnin, Christophe ; Honjo, Susumu

Investigations conducted during the GEOSECS program concluded that radium-226 (T1/2 = 1602 y) and barium are tightly correlated in waters above 2500 m in the Atlantic, Pacific and Antarctic Oceans, with a fairly uniform 226Ra/Ba ratio of 2.3 ± 0.2 dpm µmol-1 (4.6 nmol 226Ra/mol Ba). Here, we report new 226Ra and Ba data obtained at three different stations in the Pacific Ocean: stations K1 and K3 in the North-West Pacific and station old Hale Aloha, off Hawaii Island. The relationship between 226Ra and Ba found at these stations is broadly consistent with that reported during the GEOSECS program. At the three investigated stations, however, we find that the 226Ra/Ba ratios are significantly lower in the upper 500 m of the water column than at greater depths, a pattern that was overlooked during the GEOSECS program, either because of the precision of the measurements or because of the relatively low sampling resolution in the upper 500 m. Although not always apparent in individual GEOSECS profiles, this trend was noted before from the non-zero intercept of the linear regression when plotting the global data set of Ba versus 226Ra seawater concentration and was attributed, at least in part, to the predominance of surface input from rivers for Ba versus bottom input from sediments for 226Ra. Similarly, low 226Ra/Ba ratios in the upper 500 m have been reported in other oceanic basins (e.g. Atlantic Ocean). Parallel to the low 226Ra/Ba ratios in seawater, higher 226Ra/Ba ratios were found in suspended particles collected in the upper 500 m. This suggests that fractionation between the two elements may contribute to the lower 226Ra/Ba ratios found in the upper 500 m, with 226Ra being preferentially removed from surface water, possibly as a result of mass fractionation during celestite formation by acantharians and/or barite precipitation, since both chemical elements have similar ionic radius and the same configuration of valence electrons. This finding has implications for dating of marine carbonates by 226Ra, which requires a constant initial 226Ra/Ba ratio incorporated in the shells and for using 226Ra as an abyssal circulation and mixing tracer.
Understanding the role of the biological pump in the global carbon cycle : an imperative for ocean science

(The Oceanography Society, 2014-09) Honjo, Susumu ; Eglinton, Timothy I. ; Taylor, Craig D. ; Ulmer, Kevin M. ; Sievert, Stefan M. ; Bracher, Astrid ; German, Christopher R. ; Edgcomb, Virginia P. ; Francois, Roger ; Iglesias-Rodriguez, M. Debora ; Van Mooy, Benjamin A. S. ; Repeta, Daniel J.

Anthropogenically driven climate change will rapidly become Earth's dominant transformative influence in the coming decades. The oceanic biological pump—the complex suite of processes that results in the transfer of particulate and dissolved organic carbon from the surface to the deep ocean—constitutes the main mechanism for removing CO2 from the atmosphere and sequestering carbon at depth on submillennium time scales. Variations in the efficacy of the biological pump and the strength of the deep ocean carbon sink, which is larger than all other bioactive carbon reservoirs, regulate Earth's climate and have been implicated in past glacial-interglacial cycles. The numerous biological, chemical, and physical processes involved in the biological pump are inextricably linked and heterogeneous over a wide range of spatial and temporal scales, and they influence virtually the entire ocean ecosystem. Thus, the functioning of the oceanic biological pump is not only relevant to the modulation of Earth's climate but also constitutes the basis for marine biodiversity and key food resources that support the human population. Our understanding of the biological pump is far from complete. Moreover, how the biological pump and the deep ocean carbon sink will respond to the rapid and ongoing anthropogenic changes to our planet—including warming, acidification, and deoxygenation of ocean waters—remains highly uncertain. To understand and quantify present-day and future changes in biological pump processes requires sustained global observations coupled with extensive modeling studies supported by international scientific coordination and funding.
Temporal and spatial variability in sedimentation in the Black Sea : cruise report R/V Knorr 134-8, Black Sea Leg 1, April 16-May 7, 1988

(Woods Hole Oceanographic Institution, 1988-10) Honjo, Susumu ; Hay, Bernward J. ; Members of the Scientific Shipboard Party

This document represents the cruise report of the highly successful Leg 1 of the R/V Knorr cruise to the Black Sea (Cruise 134-8) as a joint Turkish-American Oceanographic Expedition (Izmir to Istanbul, April 16 to May 7,1988). The focus of Leg 1 was to study the biogeohemical variability in sedimentation in the present and throughout the anoxic history of the Black Sea with high spatial and temporal resolution. In particular, this study involved the integrated study of water column fluxes (sediment traps, suspended sediment investigations, etc.), benthic boundary layer ("fluff layer"), and laminated bottom sediments (box cores, giant gravity cores). Highlights of the cruise include the collection of 62 giant gravity cores, and 30 box cores with perfectly laminated sediment and, for the first time ever, with the intact fluff layer. Three moorings with time-series sediment traps were deployed in the abyssal regions of the eastern, central, and western Black Sea to collect continuous samples over a time period of about 1 year and 3 months. Summarized in the cruise report are logistics of the cruise, sample collections and descriptions, and preliminary discussions of observations and first measurements.
Current measurements from the northern Nordic Seas, 1983-1986

(Woods Hole Oceanographic Institution, 1987-02) Honjo, Susumu ; Wooding, Christine M. ; Wefer, Gerold

Records from ten Aanderaa current meters deployed along with 5 current meter/sediment trap mooring arrays in the Fram Strait and Greenland Basin, each deployed for approximately one year between 1983 and 1986, are presented in this data file. Data included are current vectors, temperatures, frequency spectra, and two- and three-dimensional vector diagrams.
Particle fluxes, Northeastern Nordic Seas, 1983-1986

(Woods Hole Oceanographic Institution, 1987-04) Honjo, Susumu ; Manganini, Steven J. ; Karowe, Amy ; Woodward, Bonnie L.

Seventy-nine particle. flux samples were collected from 1983 to 1986 using 7 automated time-series sediment traps at 6 stations distributed in the northern and eastern portion of the Nordic Seas as part of a German/U.S. joint program on arctic sedimentation studies. Each sample represents either one month or two weeks of sedimentation at approximately 400 m above the sea floor. In this data file the results of laboratory analysis conducted at the Woods Hole Oceanographic Institution, U.S.A. of the main sedimentological criteria: total mass, carbonate, opal, combustible, organic carbon, nitrogen, and lithogenic mass are presented in both tabular and histogram form. Results from the southern and western portion of the Nordic Seas will be published as they become available.
Eddys in the Arctic Ocean from IOEB ADCP data

(Woods Hole Oceanographic Institution, 2002-10) Krishfield, Richard A. ; Plueddemann, Albert J. ; Honjo, Susumu

Filtered and Earth-referenced ADCP data from the B92, B97 and S97 IOEBs were demodulated to remove inertial and near-inertial tidal frequencies, in order to highlight the low frequency components for examination of Arctic submesoscale eddys. This report describes the raw data, processing scheme, and numerical and graphical results of this analysis, which are also available at http://ioeb.whoi.edu/ioebeddys.htm. Using the demodulated timeseries of current profiles from each buoy, characteristics of 95 possible eddy encounters are quantified by (1) identifying anomalously large velocities associated with subsurface vortices, (2) determining the vortex centers and their drift, and (3) determining vortex properties as a function of radius and depth. Out of 44 total months of observations, 81 of the encounters were determined to be subsurface eddies, and 29 were eddy core encounters. Only 14 of the confirmed subsurface encounters were cyclonic, versus 66 anticyclonic, and one indeterminate. Within the southern and central Canadian basin portion of the Beaufort Gyre, halocline eddys with maximum velocities between 10 and 45 cm/s, centered around 140 m depth, and over 100 m thick were prevalent. Over the Northwind Ridge, eddy encounters were absent from any timeseries. Farther north and west over the Chukchi Cap, encounters resumed, but were generally smaller, more shallow and less intense (although these observations were mostly derived from a lower resolution transmitted data subset).

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