variations among the stations were small, these 

 fluctuations may be the result of horizontal 

 advection or fronts passing through the area, 

 however, more freijuent sampling is needed to 

 clearly define the process. Below 200 meters the 

 temperature and salinity appear to have re- 

 mained essentially uniform. 



To describe the water mass or masses pres- 

 ent at NOVEMBER, Figures 17-20, the tem- 

 perature versus salinity curves for each patrol, 

 were constructed using the mean values at each 

 standard depth down to 3000 meters. Examina- 

 tion of these curves reveals the warm, high 

 salinity water in the upper 200 meters which 

 underwent a cooling process and an increase 

 in salinity at the temperature range of 18.00- 

 23.00°C. Between 200 and 400 meters the 

 water mass closely approaches that of the 

 eastern North Pacific Central water described 

 by Sverdrup, et al (1942) with a temperature 

 of 10-16° and the salinity decreasing with 

 depth from 34.50 to 34.00%„. The salinity 

 minimum located between 400 and 600 meters 

 with a temperature between 5.00 and 9.00° 

 identifies the Subarctic intermediate water 

 mass of the North Pacific. Below 600 meters 

 the water column shows a very stable density 

 structure with a uniform decrease of tempera- 

 ture and increase of salinity down to 3000 

 meters. 



SUMM.\RY 



The initial oceanographic observations at 

 Ocean Station NOVEMBER by the U.S. Coast 

 Guard between July 1966 and February 1967 

 reveal a stable density structure during the 

 summer months caused by a warm, surface 

 layer and then convective mixing occurring in 

 the upper 100 meters between November and 

 February with an increase in the surface salin- 

 ity being the most probable cause. There was 

 a salinity minimum of 33.95-34.00%o lo- 

 cated at about 500 meters which is a charac- 

 teristic of the eastern North Pacific Ocean. 



The seasonal heating and cooling appeared 

 to be efi'ective to a depth of about 200 meters 

 and occurred at a high temperature level (18- 

 23°). The data indicate that a salinity-driven 

 convection probably is the dominant mixing 

 process in this area. Analysis of the data re- 

 vealed a water mass below the seasonal zone, 

 between 200 and 400 meters, which was similar 

 to the eastern North Pacific Central water 

 (Sverdrup, et al, 1942), t = 10-16° SC = 

 34. 00-34. 50 %„. Beneath this Central water 

 was a Subarctic water mass characterized 

 by a salinity between 34.00 and 34.10%o. 

 The deep water below 600 meters was essen- 

 tially uniform during the entire observational 

 period and showed a gradual increase of salin- 

 ity and decrease of temperature with depth. 



Literature Cited 



LaFond, E. C. 1951. Processing Oceanographic Data. 

 U.S. Navy Hydrographic Office. Pub. No. 614, 114 

 pp. 



Sverdrup, H. U., M. W. Johnson and R. H. Fleming, 

 1942. The Oceans; Their Physics, Chemistry, and 

 General Biology. New York; Prentice-Hall, 1087 p. 



Thomas, R. W. and D. E. Amstutz, 1966. Ocoanographic 

 Station Data, AGOR Cruise No. 056510, USNS 

 CHARLES H. DAVIS (T-AGOR 5), Informal 



Manuscript No. 66-2. U.S. Naval Oceanographic 

 Office, Washington, D.C. 



Tully, J. P. 1964. "Oceanographic Regions and Proc- 

 es.ses in the Seasonal Zone of the North Pacific 

 Ocean", Studies on Oceanography. Edited by Kozo 

 Yoshida, University of Washington Press, p.p. 68-74. 



U.S. Na\'y Hydrographic Office, 1955. Instruction 

 Manual for Oceanographic Ohsen^ations, 2nd Edi- 

 tion, U.S.N.H.O. Publication 607, 21 Op 



