The Trade Wind Zone Oceanography Pilot Study 

 Part VI: Townsend Cromwell Cruises 16, 17, and 21 

 May and June 1965 and January 1966 



By 



Robert L. Charnell, David W. K. Au 

 and Gunter R, Seckel 



ABSTRACT 



A standard grid of oceanographic stations in an area bounded by lat. 10° and 

 26° N., and long. 148° and 157° W., was occupied at monthly intervals between 

 February 1964 and June 1965. For the last regular cruises, Townsend Cromwell 

 cruises 16 and 17, May and June 1965, oceanographic station data are tabulated, 

 BT data are presented in vertical sections, and the distribution of surface 

 temperature, surface salinity, and surface dynamic height relative to 1,200 m. 

 are shown in charts for each cruise. Methods and procedures as well as the 

 limitations of the data are discussed. Oceanographic station data from Townsend 

 Cromwell cruise 21 in January 1966, consisting of a single profile of stations 

 between lat. 10° and 26.5° N. along long. 154° W., have been included. 



INTRODUCTION 



This is the last of a series of reports pre- 

 senting physical oceanographic data of the 

 Trade Wind Zone Oceanography Pilot Study 

 conducted by the Bureau of Commercial Fish- 

 eries Biological Laboratory, Honolulu. The data 

 were obtained during a series of 16 monthly 

 cruises between February 1964 and June 1965 

 over a set station pattern in an area near the 

 Hawaiian Islands bounded approximately by lat. 

 10° and 26° N. and long. 148° and 157° W. In 

 addition to the series of monthly cruises, the 

 field program of the pilot study was extended to 

 include a single profile of stations along long. 

 154° W. in January 1966. 



The complete set of observations represents 

 a three-dimensional time-sequence distribution 



Note. --Robert L. Charnell, Oceanographer , 

 presently with Hazelton Nuclear Science Corp., 

 Palo Alto, California 94303, formerly with 

 Bureau of Commercial Fisheries Biological Lab- 

 oratory, Honolulu, Hawaii; David W. K. Au, 

 Physical Science Technician and Gunter R. 

 Seckel, Oceanographer, Bureau of Commercial 

 Fisheries Biological Laboratory, Honolulu, 

 Hawaii 96812. 



of properties (temperature, salinity....) in the 

 trade wind zone of the central North Pacific. It 

 is a pilot study of an investigation in which 

 seasonal changes in the distribution of proper- 

 ties are to be explained in terms of 1) seasonal 

 changes in the processes of net heat and water 

 exchange across the sea surface, and 2) the 

 effects of seasonal changes in wind stress and 

 water motion. The Trade Wind Zone Oceanog- 

 raphy Program was planned by Gunter R. Seckel 

 and is carried out under his direction by HL 

 (Bureau of Commercial Fisheries Biological 

 Laboratory, Honolulu). 



This report contains the BT (bathythermo- 

 graph) and oceanographic station data for 

 cruises 16, 17, and 21, the last cruises in the 

 series. Figure 1 shows the cruise track for 

 cruises 16 and 17 and gives the position of the 

 Nansen bottle oceanographic casts and the BT 

 casts. It also contains these data for Townsend 

 Cromwell cruise 21 with the single profile of 

 stations along long. 154° W,, including stations 

 7A to 16, 39, and one additional station, 39A, at 

 lat. 26.5° N. Although this cruise was, strictly 

 speaking, not a part of the series, the additional 

 data provide a means of comparison of oceano- 

 graphic conditions in January 1966 along long. 

 154° W. with those in January 1965. 



