NORTH PACIFIC OCEANOGRAPHY, 

 FEBRUARY - APRIL 1962 



by 



Felix Favorite and Betty-Ann Morse, Oceanographers 



Alan H. Haselwood and Robert A. Preston, Jr., Fishery Aids 



Bureau of Conamercial Fisheries 



U.S. Fish and Wildlife Service 



Seattle, Washington 



ABSTRACT 



Oceanographic data obtained at and between salmon-fishing stations in the North 

 Pacific Ocean during February to April 1962 aboard the chartered MV Bertha Ann 

 are presented and discussed. Observations obtained between the Aleutian Islands and 

 lat. 410 N, along long. 175° W, provide the first extensive winter data in this area. 



Vertical profiles of temperature, salinity, dissolved oxygen, and sigma-t to 

 1,000 meters depth, and geostrophic currents to 600 meters depth are presented 

 along long. 175° W. from the Aleutian Islands to lat. 41° N., along long. 155° W. 

 from the Alaska Peninsula to lat. 46° N. and from lat. 46° N. long. 155° W. to the 

 Washington coast. 



Analyses of data show the Alaskan Stream extended beyond long. 175° W. 

 where geostrophic velocities in excess of 10 cm. /sec. were encountered. No evidence 

 of upwelling through the halocline was revealed south of the Aleutian Islands. The 

 Subtropic boundary in the central part of the North Pacific, as indicated by the 

 vertical 34 °/oo isohaline in the surface layer, was found near lat. 42° N. This is 

 approximately the same latitude at which it has been found during summer and im- 

 plies dominant changes in the surface layer are the result of differential latitudinal 

 heating and cooling rather than advection. 



INTRODUCTION 



This is the fifth report of oceanographic 

 field work conducted in the North Pacific Ocean 

 by the Oceanographic Section of the Bureau 

 of Commercial Fisheries Biological Labora- 

 tory, Seattle, Wash., for the American Section 

 of the International North Pacific Fisheries 

 Commission (INPFC). The observations are 

 obtained to determine the oceanography of 

 the area and, also, to permit investigations 



into relationships between the physical, chemi- 

 cal, and biological conditions, and the distribu- 

 tion and abundance of salmon stocks. 



Previous reports in this series (Favorite and 

 Pedersen, 1959a and 1959b; Favorite, Callaway, 

 and Hebard, 1961; Morse, 1962 ^ have not 



"^Betty-Ann Morse. North Pacific and Bering Sea 

 Oceanography 1960 and 1961. Bureau of Commercial 

 Fisheries Biological Laboratory, Seattle, Wash, [Un- 

 published manuscriptj 



