Oceanographic work of the United States Coast Guard in the western North Atlantic in 1940 and plans for 1941

Abstract

During 1940, because of the almost total absence of ice in the vicinity of the Grand Banks of Newfoundland, only one ice-observation cruise was made by the U.S.C.G. cutter Chelan in connection with the International Service of Ice Observation and Ice Patrol in the North Atlantic Ocean. Consequently, the usual ten or a dozen fortnightly sea-surface isothermal charts of that area were not made. However, in anticipation of the possible southward drift of menacing ice, the 125-foot cutter General Greene, operating as the oceanographic vessel of the Ice-Patrol force, repeatedly surveyed the Grand Banks Region during April, May, and June. As the third survey involved going over the same area twice in as rapid succession as possible, five dynamic topographic charts resulted from the four surveys. These charts were referred to the 1,000- decibar surface although at most of the 235 oceanographic stations occupied the temperature- and salinity-measurements extended to a depth of about 1,400 meters where the depth of the water permitted. From June 25 to 29 the General Greene occupied an additional 21 oceanographic stations from the surface to as near bottom as was practicable on a short post-season cruise in the Labrador Sea between South Wolf Island, Labrador, and Cape Farewell, Greenland. These stations were disposed in the form of a single section crossing the Labrador Current, the central Labrador Sea, and a part of the West Greenland Current. Unusually extensive sea-ice off the Greenland Coast prevented the complete crossing of the West Greenland Current. Incidental data collected on the General Greene both during the season and post-season cruises consisted of barograms and sea-surface thermograms.