Stalcup
Marvel C.
Stalcup
Marvel C.
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Technical ReportWarm core ring cruise #1 : R/V Endeavor cruise no. 74(Woods Hole Oceanographic Institution, 1982-07) Stalcup, Marvel C. ; Joyce, Terrence M. ; Schmitt, Raymond W. ; Dunworth, Jane A.At 1300 hours on 12 September 1981 the research vessel ENDEAVOR departed Woods Hole on a 22 day cruise to study the physical, chemical and biological structure of warm core ring 81-D. The cruise was the first of 5 ENDEAVOR cruises planned as part of the NSF/NASA-sponsored Warm Core Ring study.
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Technical ReportHydrographic data from warm core ring 82-B(Woods Hole Oceanographic Institution, 1985-07) Stalcup, Marvel C. ; Joyce, Terrence M. ; Barbour, R. Lorraine ; Dunworth, Jane A.Hydrographic data are presented from three cruises to Warm Core Ring 82-B during April-August 1982. These data include a sampling of the 2 db pressure, temperature, salinity and oxygen measurements obtained with a CTD-02 profiler, manufactured by Neil Brown Instrument Systems, together with water sample measurements of salinity, oxygen, silica, nitrate and phosphate. Charts showing the station positions and selected profiles of the various parameters are presented. Bi-monthly cruises aboard the R/V Endeavor show only slight changes in the ring between April and June. Interactions between the ring and the Gulf Stream before the August cruise however, reduced the volume of the central core of the ring by about 90 percent.
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Technical ReportAutomated oxygen titration and salinity determination(Woods Hole Oceanographic Institution, 1990-08) Knapp, George P. ; Stalcup, Marvel C. ; Stanley, Robert J.This report describes a newly developed automated Winkler titration system for dissolved oxygen in seawater which is presently in use at the Woods Hole Oceanographic Institution. This amperometric, calculated, endpoint system was compared with two different automated and one manual Winkler method during a recent cruise. The four different methods agreed to within about 0.04 ml/l. The system described here measures the titrant needed to reach the endpoint with a resolution better than 0.001 ml. The standard deviation of replicate samples is 0.005 ml/l and the accuracy is about 0.02 ml/l. A technique to automatically acquire conductivity ration measurements and calculate salinity using a Guildline Autosal Salinometer is also described.
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Technical ReportAutomated oxygen titration and salinity determination(Woods Hole Oceanographic Institution, 1990-08) Knapp, George P. ; Stalcup, Marvel C. ; Stanley, Robert J.This report describes a newly developed automated Winkler titration system for dissolved oxygen in seawater which is presently in use at the Woods Hole Oceanographic Institution. This amperometric, calculated endpoint system was compared with two different automated and one manual Winkler method during a recent cruise. The four different methods agreed to within about 0.04 ml/l. The system described here measures the titrant needed to reach the endpoint with a resolution better than 0.001 ml. The standard deviation of replicate samples is 0.005 ml/l and the accuracy is about 0.02 ml/l. A technique to automatically acquire conductivity ratio measurements and calculate salinity using a Guildline Autosal Salinometer is also describe.
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Technical ReportUSNS Bartlett cruise 40-B data report(Woods Hole Oceanographic Institution, 1983-06) Stalcup, Marvel C. ; Joyce, Terrence M. ; Barbour, R. LorraineA joint cruise with Dr. Michael Gregg of the Applied Physics Laboratory at the University of Washington was conducted from 8-24 January, 1983, aboard the USNS Bartlett to study the effects of wintertime cooling in a warm core ring. At the beginning of the cruise an XBT survey of ring 821 (found at 40°40'N, 66°W, east of the New England Seamounts) showed a rather confused pattern of surface temperature and salinity with the average depth of the mixed layer about 30m. On January 16-17, a storm passed near the ring with winds to 45 knots and temperatures below 0°C. An XBT survey at the end of the cruise showed that vertical mixing and cooling during the outbreak of cold air resulted in a more coherent pattern in the surface temperature and salinity of the ring and an increase in the thickness of the mixed layer to 180 m.
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Technical ReportApplication of acoustic-doppler current profiler and expendable bathythermograph measurements to the study of the velocity structure and transport of the Gulf Stream(Woods Hole Oceanographic Institution, 1988-09) Joyce, Terrence M. ; Dunworth, Jane A. ; Schubert, David M. ; Stalcup, Marvel C. ; Barbour, R. LorraineWe have addressed the degree to which Acoustic-Doppler Current Profiler (ADCP) and expendable bathythermograph (XBT) data can provide quantitative measurements of the velocity structure and transport of the Gulf Stream. An algorithm has been used to generate salinity from temperature and depth using an historical Temperature/Salinity relation for the NW Atlantic . Results have been simulated using CTD data and comparing real and pseudo salinity files. Errors are typically less than 2 dynamic cm for the upper 800 rn out of a total signal of 80 cm (across the Gulf Stream). When combined with ADCP data for a near-surface reference velocity, transport errors in isopycnal layers are less than about 1 Sv (106 rn3 /s), as is the difference in total transport for the upper 800 rn between real and pseudo data . The method is capable of measuring the real variability of the Gulf Stream, and when combined with altimeter data, can provide estimates of the geoid slope with oceanic errors of a few parts in 108 over horizontal scales of 500 krn .
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Technical ReportDissolved oxygen measurments in sea water at the Woods Hole Oceanographic Institution(Woods Hole Oceanographic Institution, 1989-07) Knapp, George P. ; Stalcup, Marvel C. ; Stanley, Robert J.This report describes a modified Winkler titration technique that has been used for the past 25 years at the Woods Hole Oceanographic Institution (WHOI). During this time most of the dissolved oxygen measurements made at sea by WHOI personnel have been analyzed with this technique and only relatively minor, evolutionary changes in the procedures and equipment have occurred. These changes, however, have improved the precision and accuracy of deep-sea dissolved oxygen measurements to 0.005 ml/l and 0.02 ml/l respectively.
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Working PaperResults of an oxygen/salinity comparison cruise on the R/V Vernadsky : June 27 to July 8, 1991(WOCE Hydrographic Programme Offce, Woods Hole Oceanographic Institution, 1992-07) Joyce, Terrence M. ; Bacon, Sheldon ; Kalashnikov, Pave ; Romanov, Alexander ; Stalcup, Marvel C. ; Zaburdaev, VladimirThis report summarizes the work, under the auspices of the WOCE Hydrographic Programme (WHP), which took place on the R/V Akademik Vernadsky in June-July 1991. The goal of the exercise was an international comparison/training cruise to obtain comparisons of water sampling methods and analytical techniques employed by several groups for the oceanographic measurement of salinity and oxygen in seawater. The training aspect was formalized in a pre-cruise practicum held on board the vessel by Dr. Fred Culkin and Mr. Paul Ridout of Ocean Scientific International, the manufacturer of IAPSO Standard Seawater, At-sea comparisons of Russian Reference Water, manufactured in Moscow, were made with IAPSO water. Further work involved comparisons of a Guildline and a pair of SOKOL salinometers using reference water and natural seawater collected on the cruise. While the agreement among the salnometers was quite good and at the level of acceptability for the WHP, it was discovered that lack of thermal equilbration of the salinity samples run on the SOKOLs led to substantial "errors" at large depths (or for cold water samples). This could not have been anticipated before the cruise and would have been missed in a shore-based or laboratory exercise. All five groups making oxygen comparisons benefitted from the technical exchange afforded by the cruise and, as a result of reconciling inter-group differences, have identified procedural changes they wil make in the future in order to achieve the high standards required by the WHP, The technical interaction, which amounted to "training" for all groups, was greatly facilitated by the cooperation of Captain Malnovsky, Chief Scientist Panteleyev, the scientists from MHI, Sevastopol, and the crew of the Vernadsky. On the Vernadsky comparison cruise, a shore-based practicum was held prior to sailing in order to review the theory and measurement of salinity. The cruise itself, which took place between 27 June and 8 July 1991, was in the NE Atlantic to the west of Madeira. An international group of experts in salnity and oxygen measurements was drawn from the United Kingdom (UK), Spain, Russia, Ukraine, and the United States (US). Except for one of the five groups, measured oxygen values in the range of 3-5 mIll (concentration units are used throughout) agreed with one another within :11%, which exceeds the WOCE requirements by a factor of 2. Subsequent analyses of the differences by all five groups could account for much of the observed inter-group variations, Intra-group precision was generally in the range of 0,1-0.4%, As a result, of a low oxygen sparging experiment in which sample oxygens 0: 1.2 mIll were generated, substantial inter-group differences of :1.08 mIll were found indicating that oxygen specifications for WOCE need to be expressed as both a percent "error" and a low oxygen bias. The salinity comparison component of the cruise enabled comparison of various batches of Russian Reference Water (RRW) of various salnities (10, 20, 30, 35 and 40) against IAPSO Standard Seawater (SSW) of various salinities (10, 30, 35 and 38); inferences could then also be drawn on the relative performance of the two types of salinometer (Guildline Autosal 8400 and SOKOL 4602) used during the experiment. Under quasilaboratory conditions, the machines produced mean results different by no more than 0.001 in salinity for salinity 35 RRW, standardizing against salinity 35 SSW. The other salnities produced less conclusive results, but the three salinometers deviated by no more than 0.003 from the expected value over a wide range of salinities. Under operational conditions (analysis of duplicate samples collected from CTD casts) a mean bias emerged between machines of approximately 0.005 in salinity (SOKOL fresher than Guildline), Subsequent investigations tentatively ascribed this bias to non-equilbration of deep (cold) samples in the Russian system.
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Technical ReportCruise summaries of Oceanus cruises 205, leg 8, and 216(Woods Hole Oceanographic Institution, 1991-04) Joyce, Terrence M. ; Stalcup, Marvel C. ; Barbour, R. Lorraine ; Dunworth, Jane A. ; Schubert, David M.A study of the upper ocean thermal and density structure in the northwestern Atlantic in 1989 compared temperature and density measurements made with Expendable Bathythermograph (XBT) and Conductivity-Temperature-Depth instruments with current data from an acoustic Doppler current profiler and satellite infrared imagery and altimetry. Two cruises were made in the spring and winter of 1989 with the goal of directly measuring the upper ocean currents and variabilty of the Gulf Stream. The XBT observations were used to extend the measured velocities geostrophically from the near-surface region to depths of 750 meters, thereby allowing transport estimates to be made for the upper ocean. In April the measurments were compared and used with the GEOSAT altimeter which, unfortunately, was not operating during the December cruise.
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Technical ReportProgress in the measurement of salinity and oxygen at the Woods Hole Oceanographic Institution(Woods Hole Oceanographic Institution, 1987-01) Knapp, George P. ; Stalcup, Marvel C.Improvements in the measurement of salinity and dissolved oxygen during the past few years at WHOI have increased the accuracy of salinity observations to +/- 0.001 ppt and that of dissolved oxygen determinations to +/- 0.04 ml/1. These improvements are attributable to the careful maintenance of the sample collection and analysis equipment, the construction of portable, sea going laboratories in which the temperature is constant to +/- 1 degree C and the skillful use of an Autosal 8400-A salinometer and a Metrohm Titroprocessor by well trained technicians. An automated data logging system eliminates transcription errors and facilitates the timely calibration of the CTD sensors.
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Technical ReportHydrographic data from R/V Endeavor cruise #143(Woods Hole Oceanographic Institution, 1988-03) Stalcup, Marvel C. ; Joyce, Terrence M. ; Bullister, John L. ; Barbour, R. Lorraine ; Dunworth, Jane A.Hydrographic data collected during R/V Endeavor cruise 143 is presented as a preliminary study of subduction in the northeast Atlantic south of the Azores Front. The front is clearly defined at the northern end of CTD section #1 which also shows a layer of 16-18°C water subducted to the south. Section #2, 280 km to the east, is dominated by a large cyclonic ring with characteristics similar to 'eastern' rings reported earlier . An anomalously salty parcel of Mediterranean water in this section is typical of highly saline lenses seen in the Canary Basin.
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Working PaperA comparison of methods for the determination of dissolved oxygen in seawater(WOCE Hydrographic Programme Office, Woods Hole Oceanographic Institution, 1991-08) Culberson, Charles H. ; Knapp, George P. ; Stalcup, Marvel C. ; Williams, Robert T. ; Zemlyak, FrankAn intercalibration of dissolved oxygen methods was conducted at 2 stations in the Sargasso Sea between April 28 and May 3, 1990. The experiment compared three techniques using automated endpoint detection with the manual Winkler method using a starch endpoint. Institutions participating in the intercomparison were the Bedford Institute of Oceanography (automated photometric titration), the University of Delaware (automated amperometric titration), the Scripps Institution of Oceanography (manual titration), and the Woods Hole Oceanographic Institution (automated amperometric titration). Differences in measured oxygen concentrations between institutions were encouragingly small. However, small, systematic differences in dissolved oxygen between institutions did exist. The range between the highest and lowest oxygen values reported by the 4 institutions never exceeded 0.6% over the entire concentration range studied (3.4 to 6.2 mlj1). The good agreement is probably due to the use of the essentials of Carpenter's (1965) modification of the Winkler method by all institutions. The intercalibration revealed several aspects of dissolved oxygen measurements that require further research: (1) the intercalibration should be extended to very low oxygen concentrations; (2) procedures for measur ing and applying corrections for the seawater blank need to be formalized; (3) a simple procedure to measure the temperature of seawater at the time of sampling needs to be developed; and (4) the solubility of atmospheric oxygen in the Winkler reagents must be measured as a function of temperature. The intercalibration also revealed that analytical techniques required for precise and accurate volumetric measurements were often not applied, even by experienced analysts. It was found that uncalibrated pipets were used to dispense standards, that the volumes of oxygen flasks were not corrected for buoyancy, and that corrections for the thermal expansion of aqueous solutions were often not applied.
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Technical ReportHydrographic station data : Caribbean Sea, Atlantis II cruise 78 and Knorr cruise 37(Woods Hole Oceanographic Institution, 1974-12) Metcalf, William G. ; Stalcup, Marvel C. ; Zemanovic, Marguerite E.During Cruise 37 of the Research Vessel KNORR,91 hydrographic stations were occupied,most of them in the general area of the Windward Passage, eastern Cayman Basin, Mona Passage and across the Caribbean Sea from Puerto Rico to Venezuela. Vertical profiles of potential temperature, salinity, dissolved oxygen and dissolved silicate are presented. The data lists include, in addition to the observed parameters, such computed values as pressure, potential temperature, potential density, specific volume anomaly, sound velocity, dynamic height, potential energy, Vaisala frequency and Vaisala period. Also included in the data lists are 28 hydrographic stations occupied during November 1973 on Cruise 78 of the Research Vessel ATIANTIS II in the Windward Passage, Central Caribbean Sea and the Atlantic Ocean just east of the Lesser Antilles.
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Technical ReportWater sample and expendable bathythermograph (XBT) data from R/V Atlantis II cruise 107 : Leg X(Woods Hole Oceanographic Institution, 1981-09) Piola, Alberto R. ; Georgi, Daniel T. ; Stalcup, Marvel C.This report summarizes in graphical and tabular form the continuous conductivity-temperature-pressure-dissolved-oxygen (CTD0 2) data collected during the R/V ATLANTIS II Cruise 107, Leg X. These data were collected in the austral winter of 1980 as part of the International Southern Ocean Studies (ISOS) to evaluate and test various Antarctic Intermediate Water formation and circulation mechanisms.
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Technical ReportHydrographic data from R/V Endeavor cruise #90(Woods Hole Oceanographic Institution, 1986-03) Stalcup, Marvel C. ; Joyce, Terrence M. ; Barbour, R. Lorraine ; Dunworth, Jane A.The final cruise of the NSF sponsored Warm Core Rings Program studied a Warm Core Ring (WCR) in the Fall of 1982 as it formed from a large northward meander of the Gulf Stream. This ring, known as 82-H or the eighth ring identified in 1982, formed over the New England Seamounts near 39.5°N, 65°W. Surveys using Expendable Bathythermographs, Conductivity-Temperature-DepthOxygen stations and Doppler Current Profiling provide a look at the genesis of a WCR. These measurements reveal that WCR 82-H separated from the Gulf Stream sometime between October 2-5. This ring was a typical WCR with a diameter of about 200 km and speeds in the high velocity core of 175 em/sec. Satellite imagery of 82-H following the cruise showed that it drifted WSW in the Slope Water region at almost 9 km/day, had at least one interaction with the Gulf Stream and was last observed on February 8, 1983 at 39°N, 72°W.