Progress in the measurement of salinity and oxygen at the Woods Hole Oceanographic Institution

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.Funding was provided by the National Science Foundation under grant Nos. OCE 85-15642 and OCE 82-13967

Water sample and expendable bathythermograph (XBT) data from R/V Atlantis II cruise 107 : Leg X

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.Prepared for the National Science Foundation - Office of International Decade of Ocean Exploration under Grant OCE-78-22223

Dissolved oxygen measurments in sea water at the Woods Hole Oceanographic Institution

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.Funding was provided by the National Science Foundation through grant Number OCE 87-16910

Automated oxygen titration and salinity determination

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.Funding was provided by the National Science Foundation through Grant No. OCE88-22542

Deep Caribbean inflow through the Anegada -- Jungfern Passage

The Jungfem Passage Sill at a depth of 1815 meters is the controlling sill for the deepest water exchange between the Atlantic Ocean and the Venezuelan Basin of the Caribbean Sea. Data from moored current meters and temperature recorders, STD\u27s and hydrographic stations obtained during March and April 1972 are interpreted as indicating an average net flow of 56 × 103 m3 sec-1 of deep Atlantic water into the Caribbean Sea. Current speeds as high as 32 cm sec-1 were recorded on the sill near the axis of the inflow, and the average velocity during 38 days was 20 cm sec-1...

Invariant submanifold for series arrays of Josephson junctions

We study the nonlinear dynamics of series arrays of Josephson junctions in the large-N limit, where N is the number of junctions in the array. The junctions are assumed to be identical, overdamped, driven by a constant bias current and globally coupled through a common load. Previous simulations of such arrays revealed that their dynamics are remarkably simple, hinting at the presence of some hidden symmetry or other structure. These observations were later explained by the discovery of (N - 3) constants of motion, each choice of which confines the resulting flow in phase space to a low-dimensional invariant manifold. Here we show that the dimensionality can be reduced further by restricting attention to a special family of states recently identified by Ott and Antonsen. In geometric terms, the Ott-Antonsen ansatz corresponds to an invariant submanifold of dimension one less than that found earlier. We derive and analyze the flow on this submanifold for two special cases: an array with purely resistive loading and another with resistive-inductive-capacitive loading. Our results recover (and in some instances improve) earlier findings based on linearization arguments.Comment: 10 pages, 6 figure

Cruise summaries of Oceanus cruises 205, leg 8, and 216

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.Funding was provided by the National Science Foundation through Grant No. OCE-SS-1769S

USNS Bartlett cruise 40-B data report

A 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.Prepared for the Office of Naval Research under Contract N00014-82-C-0019; NR 083-004