OCEANOGRAPHIC OBSERVATIONS IN THE 

 CENTRAL NORTH PACIFIC, SEPTEMBER 1954 - AUGUST 1955 



By 



James W. McGary, Cceanographer , and Edward D. StroupJ. 

 Pacific Oceanic Fishery Investigations 

 Honolulu, T. H. 

 Bureau of Commercial Fisheries 



1/ 



This report is the fourth in a series of 

 oceanographic data reports by the Pacific Oceanic 

 Fishery Investigations (POFI) on the waters to 

 the north and northeast of the Hawaiian Islands. It 

 contains physical and chemical data collected on 

 three oceanographic cruises between September 

 1954 and August 1955. The surveys covered by 

 this and the previous reports were made as part 

 of the albacore, Germo alalunga, investigations 

 which are being supported by funds made avail- 

 able by the Saltonstall-Kennedy Act. The first 

 two reports (McGary and Stroup 1956; McGary, 

 Jones, and Austin, 1956) embody only data col- 

 lected on individual oceanographic cruises during 

 the winter of 1954 and summer of 1955; the third 

 report (Callaway 1957) contains oceanographic 

 data collected on three exploratory fishing 

 cruises during the summer and fall of 1956. The 

 manner and detail of the presentation in this re- 

 port are somewhat different from those of the 

 first two of the series. The text does not con- 

 tain the detailed discussion and partial analysis 

 of the data that was included in the first report 

 (McGary and Stroup 1956), but like the second 

 (McGary, Jones, and Austin, 1956) it merely 

 contains a discussion of the methods and a re- 

 sume of the results. In common with the first 

 report, however, it contains plots of the lateral 

 and vertical fields of the various parameters in 

 addition to the tabulated data. The biological 

 data taken on these cruises and the limited phys- 

 ical data taken on fishing cruises in conjunction 

 with the oceanographic cruises have been pub- 

 lished elsewhere, as cited in this report. 



The first survey, Charles H. Gilbert cruise 

 17, during the period September 17 to November 

 7, 1954, was confined to the area between 21°N. 

 and45°N. latitude, 160°W. to 170*E. longitude. 

 An exploratory-fishing cruise, John R. Manning 

 cruise 22, was made concurrent with this survey, 

 and the data have been analyzed and published 

 by Shomura and Otsu (1956). The second survey. 



U Formerly Physical Science Aid, POFI, 

 Honolulu, T. H. Present address, The Johns 

 Hopkins University, Baltimore, Md. 



Hugh M. Smith cruise 27, during the period 

 January 5 to February 21, 1955, covered the 

 area bounded by 20'N. and 39°N. latitude be- 

 tween 160°W. and 170"E. longitude. The latter 

 part of John R. Manning cruise 23, an explora- 

 tory fishing cruise, was made concurrent with 

 this survey; the resulting data are included in 

 the report by Shomura and Otsu (1956). The 

 third survey, Hugh M. Smith cruise 30, was 

 made during the period July 15 to August 28, 

 1955, in the area between the Hawaiian Islands 

 and 49°30'N. , from 157°30'W. to 180*. This 

 cruise was a part of Operation NORPAC, a 

 quasi-synoptic oceanographic and biological 

 survey of the Pacific north of 20"N. , including 

 a portion of the Bering Sea, undertaken jointly 

 by research agencies of Canada, Japan, and the 

 United States. The tabulated data and tempera- 

 ture cross sections have already been published 

 (McGary, Jones, and Austin, 1956), and much 

 of the resulting data will also be incorporated 

 in an atlas which is to be published jointly by 

 Scripps Institution of Oceanography and the 

 Japanese Hydrographic Office. 



CHARLES H. GILBERT CRUISE 17 



Itinerary 



The Gilbert departed from Pearl Harbor on 

 September 17, 1954. The vessel stopped at 

 Midway Islands on October 11-14, 1954, for 

 fuel, stores, and to exchange personnel. A 

 brief stop was made at Laysan Island on Novem- 

 ber 3 to inspect the wildfowl refuge and to make 

 a bait-fish survey of the reefs. The vessel re- 

 turned to Pearl Harbor on November 7, 1954. 

 The cruise track and station positions are shown 

 in figure 1. 



Primary Missions 



1. Forty oceanographic stations were occupied 

 at the positions indicated in figure 1. 

 Twenty-five scheduled stations were 

 omitted because of high winds and rough 

 seas. 



