are the significant air masses associated with the circulationo The 

 Pacific polar front and the Arctic front are the zones of interaction 

 associated with cyclogenesis. The stronger Pacific polar front lies to 

 the south of the area in winter, but retreats northward over the area as 

 s\unBier approaches. 



Meteorological conditions encountered in the Bering Sea by the 

 NORTHWIND between $ March and 18 April 1955, and by the BURTON ISLAND 

 between 21 April and 27 May 1955 are shown on composite charts in 

 Figures 2U through 33e These charts represent more of a climatic 

 pattern than a climatic mean. Data were obtained from oceanographers • 

 logs and oceanographic log sheets. Summaries of the meteorological data, 

 taken from the ships ' report, are presented in Tables 3 and U, 



D, Currents 



Prevailing surface currents during the summer are shown in Figure 3Uo 

 They are based on current observations during summer cruises, ice move- 

 ment, and the distribution of physical properties. Changing wind condi- 

 tions and tidal currents produce large day-to-d^ variations. 



Several attempts were made to record currents with an Ekman current 

 itKter, but no revolutions of the impeller were observed^ Figure 35 

 (plotted by Dr. Edward M. Little, of NEL) shows the ship's drift while 

 fast in a 1-raile ice floe from 22 March to 5 April, The drift track is 

 based on daily positions at 0800, 1200, and 2000 (local time). Drift 

 was predominantly south but variations observed along the route suggest 

 the influence of tidal currents. 



NOTE: Drift track was evidently based upon more than 3 daily positions, 

 for numerous changes in course are plotted between these points. Also, 

 positions at other hours are plotted. 



32 



