OCEAN EDDIES IN A LARGE-SCALE SURVEY AREA

Abstract

To make a synchronous survey of an eddy field over a large area (300 miles × 300 miles) the Institute undertook in late 1987 the interdepartmental Megapoligon expedition in the northwestern Pacific Ocean, east of Japan and north of the Kuroshio current. This expedition included 11 research ships. The average climatic system of currents in the area that studied included the warm Kuroshio Current entering from the south which separates from the coast of Honshu at about 35° N and turns eastward, it is one link in the anticyclonic circulation. The cold Kurile Current or Oyashio, proceeding from the NNE, turns eastward at about 40° N, forming with the northern branch of the Kuroshio and the Tsugaru Current the Subarctic Current; at about 135° W the North Subarctic Current branches off from it toward the NE. These currents have cyclonic vorticity. All are fronts that separate waters with different properties. This paper discusses in more detail the direct current measurements.