ALBERT

Description: © The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Continental Shelf Research 124 (2016): 165-181, doi:10.1016/j.csr.2016.06.005.

Description: A new hydrographic climatology has been created for the continental shelf region, extending from the Labrador shelf to the Mid-Atlantic Bight. The 0.2-degree climatology combines all available observations of surface and bottom temperature and salinity collected between 1950 and 2010 along with the location, depth and date of these measurements. While climatological studies of surface and bottom temperature and salinity have been presented previously for various regions along the Canadian and U.S. shelves, studies also suggest that all these regions are part of one coherent system. This study focuses on the coherent structure of the mean seasonal cycle of surface and bottom temperature and salinity and its variation along the shelf and upper slope. The seasonal cycle of surface temperature is mainly driven by the surface heat flux and exhibits strong dependency on latitude (r≈−0.9). The amplitude of the seasonal cycle of bottom temperature is rather dependent on the depth, while the spatial distribution of bottom temperature is correlated with latitude. The seasonal cycle of surface salinity is influenced by several components, such as sea-ice on the northern shelves and river discharge in the Gulf of St. Lawrence. The bottom salinity exhibits no clear seasonal cycle, but its spatial distribution is highly correlated with bathymetry, thus Slope Water and its intrusion on the shelf can be identified by its relatively high salinity compared to shallow, fresher shelf water. Two different regimes can be identified, especially on the shelf, separated by the Laurentian Channel: advection influences the phasing of the seasonal cycle of surface salinity and bottom temperature to the north, while in the southern region, river runoff and air-sea heat flux forcing are dominant, especially over the shallower bathymetry.

Description: Support from NSF OCE PO to Y-OK (OCE-1242989 and OCE-1435602) and SJL (OCE-1332666).

Description: 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.

Description: Funding was provided by the National Science Foundation under grant Number OCE 80-16983.

Description: This 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.

Description: Prepared for the National Science Foundation under Grants OCE89-07815, and OCE92-06184, T. Joyce, Principal Investigator; Vetlesen Funds, Woods Hole Oceanographic Institution; and with support from the Intergovernmental Oceanographic Commission.