REPORT ON OCEANOGRAPHY 53 



casting hydrographic conditions in this area (KH, 2, 1951). M. Nagai 

 discussed the annual variation of sea water temperature and salinity 

 and made several detailed statistical analysis and stressed that their 

 fluctuations due to advocation are very important in forecasting these 

 elements (KJ, 4, 1953). 



In 1950 T. Ichiye treated the meandering pattern in the isotherms 

 observed on the surface along the polar front as the horizontal inter- 

 nal waves formed along the boundaries between warm and cold water. 

 (US, 28, 1950). 



M. Uda also discussed the characteristic feature of the yearly va- 

 riation of coastal water temperature and pointed out the advance and 

 lag of the seasons peculiar to each year. His conclusion was that it is 

 most important to carry out the hydrographic observations during the 

 winter months as frequently as possible (US, 30, 1952, 5-7). A survey 

 of the fisheries in relation to hydrographic fluctuation was also dis- 

 cussed by Uda in 1952 (TUFJ, 38, 1952, 363-389). 



Classification of the types of the annual variations of water tem- 

 perature was made by T. Ichiye. He mentioned three types: seas or 

 lakes, bay in which tidal currents are strong, and open sea, with several 

 important discussions (KMOM, 10, 1952). 



M. Hanzawa mentions some examples of an abrupt change in hy- 

 drographic conditions from his experiences in the observations on board 

 the weather ships. He points out that the advection due to wind effect 

 is responsible for these changes (OM, 4, 1952). 



J. Masuzawa gives some examples showing that a typhoon some- 

 times acts as a motive for the hydrographic changes in the area close to 

 their tracks (KH, 1, 1950, 118-123). 



Method of forecasting the hydrographic conditions off Sanriku 

 coast based on the isentropic analysis, was reported by Fukuoka (KH, 



1, 1950, 30). 



Forecasting sea surface temperature in the southwestern part of 

 the Japan Sea was attempted by K. Hishida (KH, 2, 1951). 



The relation between the coastal and offshore water temperature 

 and other hydrographic elements was analyzed by K. Hishida (MMOR, 



2, 1951; OM, 2, 1950). 



Ocean Currents 



In 1950, J. Fukuoka made an analysis of the Oyashio Current flow- 

 ing south in the area to the NE of Japan. He analyzed the TS-curves 

 from various stations in the Okhotsk Sea and western North Pacific 

 Ocean, and noticed that the Oyashio water and Kuroshio water can be 

 found in some latitudes close together, their boundary always oscillat- 



