北部日本海 (津軽海峡西沖周辺海域) の夏季の海況について (第1報)

Abstract

The investigations on the oceanographical conditions of the Japan Sea have been made already by many authors. The present author discusses also synoptically the general oceanographical states of the North Japan Sea (west off the Tsugaru-Straits) in summer, mainly on water mass. From the investigations the followings are made clear.(1) The stratification of water masses in the Japan Sea is complicated and is composed of the coastal water, the surface and middle layer water of Tsushima warm current, the intermediate water, the deep and bottom layer water, the surface layer water of Liman cold current, etc.(2) These, the intermadiate water, the deep and bottom layer water in the Japan Sea, are very different from that of other oceans.(3) The surface layer water has three branch currents and this fact is important in this sea area.(4) Water masses diffuse and are modified by lateral mixing along the Isentropic surface (isopycnal surface).(5) It is considered that in the Japan Sea, water temperature distribution and vertical stability show the motion of water masses and chlorinity or dissolved oxygen, the origin of water masses.