On the water mass characteristics in autumn on the continental shelf of East China Sea.

Abstract

The water mass characteristics in autumn on the continental shelf of East China Sea have been described based on the data taken during the cruises of R/V Takuyo of Hydrographic Department in 1973, 1974 and 1975. The XBT records contain very sharp seasonal thermoclines, and the vertical temperature profiles can be classified into four types, one-layer type, two-layer type, three-layer type and continuous type. The distribution of these temperature types has a good correspondence with the bottom topography. From the temperature and salinity distributions, the bottom waters found below the thermocline on the continental shelf can be well interpreted as the one which were formed in the previous winter and has remained on the spot with no influence from surrounding water. Some records having temperature inversions and many-layer structures have been also analyzed with the salinity and oxygen profiles, and these structures can be attributed to mixing process between coastal water and off-shore water.