OCEANOGRAPHIC AND METEOROLOGICAL OBSERVATIONS IN THE NORTHEAST 



AND CENTRAL NORTH PACIFIC, JULY - DECEMBER 1956 



By 



Richard J. Callaway 

 Oceanographer 

 Pacific Oceanic Fishery Investigations 

 Honolulu, T. H. 



Through an allotment of funds provided by 

 Public Law 466 of the 83rd Congress, better 

 known as the Saltonstall -Kennedy Act of 1954, 

 the Pacific Oceanic Fishery Investigations (POFI) 

 of the U. S. Fish and Wildlife Service, Honolulu, 

 T. H. , has been studying albacore distribution 

 and abundance in the North Pacific Ocean. 



In the summer and fall of 1956, POFI ves- 

 sels made three albacore fishing cruises into 

 the waters north and northeast of Hawaii. It is 

 the purpose of this report to make available to 

 interested workers the physical and chemical 

 data collected during these cruises. The data 

 presented will supplement earlier reports on 

 oceanographic observations in the area (McGary 

 et al. 1956, Shomura and Otsu 1956, McGary 

 and Stroup 1956, and Grahann 1957) and will pro- 

 vide a more complete picture of the environmen- 

 tal features which influence the seasonal 

 occurrence of albacore in the northeast Pacific. 



Table 1 defines the approximate geographic 

 limits and periods of the cruises. Track charts 

 are given in figures 1, 5, and 9. 



PHYSICAL AND CHEMICAL OBSERVATIONS 



The following observations were made on 

 each cruise unless otherwise indicated. 



Tennperature; Bathythermograph Slide Processing 



Bathythermograph lowerings to 900 feet 

 were made at approximately 30 -mile intervals 

 and while on gill -net stations. The bathyther- 

 mograph log sheets (log sheet "B") are repro- 

 duced in tables 2, 5, and 8. 



The vertical temperature sections for John 

 R. Manning cruise 32 (figs. 2-4) are plots 

 from BT slides processed at the U. S. Navy 

 Hydrographic Office. 



Sections for John R. Manning cruise 33 

 (figs. 6-8) and Charles H. Gilbert cruise 31 

 (figs. 10 - 12) are plots from BT slides proc- 

 essed at the POFI laboratory. The tempera- 

 ture corrections were made as follows. Each 

 BT slide was placed against the stop in the 

 appropriate grid and the indicated surface tem- 

 perature was noted. The algebraic difference 

 of the BT surface temperature and the bucket 

 temperature was taken. Where the difference 

 was consistent for a group of slides the average 

 was applied as a correction when reading tem - 

 peratures at depth. When an abrupt change 

 appeared (e.g., from -0.2°F. to +0.3"'F.) a 

 new average was obtained and applied to B T 

 slides which lay within that group. 



Depth correction was obtained by comparing 

 the position of the top horizontal BT trace with 

 zero depth on the grid. The difference was 

 applied to each slide when reading temperature 

 against depth. 



Throughout each cruise a continuous record 

 of surface temperature was obtained by mieans 

 of a recording thermograph. 



Salinity 



Surface samples for salinity determinations 

 were usually taken at each BT position. The 

 samples were analyzed in the POFI laboratory 

 by a modification of Knudsen's method for the 



Table 1. --Cruise limits and periods 



