Oceanographic Observations of the Subarctic-Subtropical Transition Zone in the Western North Pacific.

摘要

During the periods 6 February to 27 February 1976 and 5 April to 25 April 1976 the U.S. Naval Oceanographic Office (NAVOCEANO) survey vessel USNS SILAS BENT conducted oceanographic/geophysical surveys in the western North Pacific. Objectives of the surveys (Cruises 343613 and 343615) were to determine the oceanographic structure across the subarctic-subtropical transition zone and delineate the fronts marking the boundaries of the zone. A Bissett-Berman model 9040 SVSTD was used to obtain depth profiles of temperature, salinity, and sound velocity at each station. Expendable bathythermographs were used to determine the temperature structure between stations. The well-defined transition zone between the Subarctic Water Mass and the Central (subtropical) Water Mass is one of the more dominant oceanographic features of the North Pacific. The boundaries of the zone are marked by large temperature and salinity gradients which profoundly affect long-range sound transmission.