OCEAHOGRAPHIC OBSERVATIONS, 1957 

 EAST COAST OF THE UNITED STATES 



INTRODUCTION 



Through the cooperation of the U. S- 

 Coast Guard, the Woods Hole Oceanographic 

 Institution established in late 1955 a 

 series of oceanographic observation posts 

 at a number of lightship stations along 

 the East Coast. Each lightship was 

 furnished with a kit of oceanographic 

 equipnent and was requested to make the 

 following observations: 



Daily bathythennograph lowering. 



Dally surface water temperature reading 



Eind surface water sample. 

 Daily record of air temperature, weather, 



wind and clouds. 

 Weekly bottom water sample. 



These data have been forwarded on a 

 monthly basis to Woods Hole where they have 

 been processed. The bathythennograms have 

 been read at several levels and tabulated 

 in the accompanying tables. The surface 

 water temperatures were used as a check on 

 the bathythermograph. The water samples 

 were titrated for salinity and tabulated. 

 The records of air temperature, weather, 

 wind and clouds were used in studying the 

 other data, but are not presented here as 

 they are the same as those published in 

 the daily weather maps issued by the U. S. 

 Weather Bureau. In addition to tabulating 

 these data, mean temperatures for each 

 level for 3 equal time periods per month 

 have been determined and plotted as time 

 profiles for the year for each station. 

 The one-thirt monthly msan surface temper- 

 atures have also been plotted in ccmparison 

 with the monthly me em surface temperature 

 for the period of record of each station. 

 The surface salinity one -third monthly mesms 

 have been appended to the profiles, to- 

 gether with the weekly bottom salinity 

 values. 



Where data were incomplete, means 

 were calculated only in those cases where 

 temperature conditions appealed to be 

 static; whej?e conditions were changing, 

 means were not derived from incomplete 

 records. 



The monthly mean surface water temper- 

 atures for the year 1957 for all stations 

 are listed in table 1, for ccmparison with 

 previous records (Bumpus 1957a and b.) 



Certain independent observers have 

 kindly forwarded to us daily water temper- 

 ature readings at shore stations. These 

 data are also tabulated herein and the one- 

 third monthly mean depicting the ""nnoi 

 progression of sxirface water temperatures 

 are presented. 



C(»<MENTARY 



The 1957 cycle of temperature , both 

 surface and bottom, along the coast is 

 shown in figure 1. Contours were drawn 

 from the lO-day mean values. 



Surface temperature . 



At Portland Lightship minimen temper- 

 atures were higher and earlier than in 1956j 

 at Boston Lightship earlier and lower by 

 less than I'F. The observations at Georges 

 Shoals did not begin until late April of 

 1956, so comparison of minima is not possible. 

 The 1957 winter temperature there never fell 

 below i+O'F. Between Nantucket and Diamond 

 Shoals Lightships, minimum surface readings 

 occurred in February', on the average of a 

 month earlier than in 1956, and readings 

 were not as low. The previous year, water 

 of less than 40°F was found as far south as 

 the Chesapeake station, whereas in 1957 it 

 penetrated only so far as Bamegat Light- 

 ship. The complicated structure at Diamond 

 Shoals makes comparison of minimum temper- 

 atures misleading, but in general the first 

 three months of 1957 were appreciably 

 warmer than was the same period of 1956. 

 At Frying Pan Shoals and at Savannah the 

 1957 minima were higher by 5.2''F and 2.9''F 

 respectively. Thus, the 1957 winter was of 

 shorter duration than the I956 winter, and 

 vernal warming began earlier. At most 

 stations wanning continued in advance of both 



the mean and the 1956 record throughout the 

 spring. 



