. INTRODUCTION 



A. General 



Oceanographlc operations of the USS REQUISITE (AGS-18), USS ELDORADO 

 (AGC-11), USS ATKA (AGB-3), units of TASK FORCE 5 In the western sector of 

 the Arctic, and the USCGC EASTWIND (WAGB-279), a unit of TASK FORCE 6 in 

 the eastern sector, were conducted during the summer and autumn 1956. Oceano- 

 graphlc data collected were in support of the U.S. Navy Hydrographic Office's 

 ice forecasting program for the Arctic area. Because of the ship's primary mission, 

 all oceanographlc observations were made on a not -to -Interfere basis. 



The oceanographlc program consisted of bathythermograph (BT), current, and 

 ice observations, as well as Nansen casts and bottom sampling. A summation of 

 observations taken by all four ships is presented on Page 2. Serial (temperature, 

 salinity, density, sound velocity, and dynamic depth anomaly), current, and bottom 

 sediment data are included in this report. Ice data and bathythermograms are not 

 presented herein; these data are on file at the U.S. Navy Hydrographic Office. 



Vertical water temperatures were determined by deep-sea reversing thermom- 

 eters. Water samples were analyzed for salinity content aboard the ELDORADO, 

 ATKA, and EASTWIND. Temperature and salinity results were dispatched via 

 radio to the U.S. Navy Hydrographic Office for immediate use in ice predictions. 

 These water samples and those collected by the REQUISITE were forwarded to the 

 laboratory in the U.S. Navy Hydrographic Office for analyses and verification. 



Interpolations for oceanographlc parameters at standard depths and computa- 

 tions of density, sound velocity, and dynamic depth anomolies were accomplished 

 by an electronic computer. 



Bathythermograph observations were made In accordance with the reporting 

 procedures specified In H. O. Pub. No. 606-c, "Bathythermograph Observations," 

 2nded., 1956. 



Bottom sampling was accomplished with the Phleger corer and Clamshell sampler, 

 All samples were forwarded to the Hydrographic Office for analyses. 



Water current observations were made with the Ekman current meter. Wide 

 distribution of pellets in the compass box of the meter made current direction 

 difficult to compute. Therefore, directions were averaged by selecting the 90- 

 degree quadrant in which the most pellets were located, totaling each 10-degree 

 division of the compass box in which a pellet was located, and averaging the 

 total sum . 



