OCEANOGRAPHIC OBSERVATIONS 



NORTH ATLANTIC OCEAN STATION CHARLIE 



52»45'N, 35»30'W 



April 1967-April 1968 



by 



La^vrence J. Hannon^ 



INTRODUCTION 



Ocean Station CHAELIE is one of several 

 ocean stations in the North Atlantic Ocean at 

 which U.S. Coast Guard cutters regularly collect 

 meteorological and oceanographical data. This 

 report is the third United States Coast Guard 

 Oceanographic Report (CG 373 Series) on Ocean 

 Station CHARLIE. The two previous reports 

 cover the periods June 1964 to January 1965 

 (Husby, 1966) and May 1966 to March 1967 

 (Husby, 1968). 



DATA ACQUISITION AND 

 PROCESSING 



This report contains time series oceanographic 

 data that were collected by the U.S. Coast Guard 

 ocean station vessels at Ocean Station CHARLIE 

 (52°45'N, 35°30'W) during the period April 

 1967 to April 1968 (Table 1). 



Ocean station vessels normally maintain posi- 

 tion within a ten mile square grid centered on 

 the nominal station, operations and weather per- 

 mitting. Actual positions of the stations taken 

 during each patrol are presented in figures 1-10. 

 Only those stations taken outside the ten mile 

 square grid have been plotted. 



The observational program consisted of daily 

 Nansen casts with sampling depths of 0, 10, 30, 

 50, 75, 100, 150, 200, 400, 500, 600, 800, 1000, and 

 1500 meters. For deep casts, sampling depths 

 were 2000, 2500, 3000, and 150 and 50 meters 

 above the bottom as indicated by the vessels' 

 fathometer. In April 1968 the USCGC HAM- 



'U.S. Coast Guard Oceanographic Unit, Bldg. 159-E, 

 Navy Yard Annex, Washington, D.C. 20390. 



ILTON was one of the first ocean station vessels 

 on an ocean station to use the Bissett-Berman 

 Model 9006-N Salinity/Temperature/Depth 

 Measuring System (STD). The STD casts 

 were taken to a depth of 1500 meters each day at 

 0000, 0600, 1200, and 1800 GMT, weather and 

 other operations permitting. 



Each Nansen bottle was equipped with two 

 protected deep-sea reversing thermometers. In 

 addition five Nansen bottles, used at 200 meters 

 and below, were fitted with an unprotected 

 thermometer to allow determination of thermo- 

 metric depths. Uncorrected main and auxiliary 

 temperatures were transmitted via radio teletype 

 to the Coast Guard Oceanographic Unit for 

 real-time data processing and quality control. 



Corrected temperatures and thermometric 

 depths were computed with a Digital Equipment 

 Corp. PDP-5 computer. After being quality 

 controlled, these data were relayed to Fleet 

 Weather Center, Norfolk, Va., and to Fleet 

 Numerical Weather Central, Monterey, Calif., 

 for use in forecasting synoptic oceanic conditions. 



Salinities were determined aboard ship using 

 an inductive salinometer. The conductivity 

 values obtained were converted to salinities using 

 the International Oceanographic Tables pub- 

 lished jointly in 1966 by UNESCO and the Na- 

 tional Institute of Oceanography of Great 

 Britain. The results were sent to the Coast 

 Guard Oceanographic Unit by radio teletype at 

 intervals of 3-5 days. A second water sample 

 was collected from the top and bottom Nansen 

 bottles; these samples were processed at the 

 Coast Guard Oceanographic Unit as a quality 

 control. 



