This salinity minimum ranges between 33.95 

 and 34.05 "/nd and identifies the upper limit of 

 the North Pacific Intermediate Water at NO- 

 VEMBER. Below 600 meters the salinity in- 

 creases with depth to a value of about 34.56 "/oo 

 at 1500 meters. 



SUMMARY 



Ocean Station NOVEMBER is located in the 

 Subtropical Region at the eastern North Pacific 

 Ocean which is known to be under the influ- 

 ence of a clockwise gyral motion. In the vicin- 

 ity of NOVEMBER the flow is so slow, how- 

 ever, that the near surface waters have time to 

 become adjusted to the local atmospheric cli- 

 mate (Tully, 1964). At the latitude of NO- 

 VEMBER the seasonal range of temperature is 

 relatively small, 18 to 24°C, and the tempera- 

 ture of the surface waters is maintained at a 

 high level. The dominant climatic influence in 

 the vicinity of NOVEMBER is the excess of 

 evaporation over precipitation. The excess 

 evaporation increases the salinity of the sur- 

 face waters and therefore increases the den- 

 sity, which, in turn, would promote convective 

 mixing. 



The results of the oceanographic observa- 

 tions at Ocean Station NOVEMBER between 

 March 1967 and March 1968 revealed a stable 



temperature structure during the entire period 

 with a maximum surface temperature of 

 24.5 °C in September and a minimum of about 

 17.8°C in March 1968. A convective mixing 

 process was evidenced in January and Febru- 

 ary 1968 by the rise in temperature at the 100, 

 200, 300, and 400 meters levels. Due to the sta- 

 ble temperature structure at NOVEMBER, 

 this increase in temperature at the 100-400 

 meter levels could be explained only by a 

 convective mixing process or by advection. Due 

 to the increase of salinity at these levels dur- 

 ing this period the convective mixing process, 

 caused by an increase in surface salinity, is the 

 most likely explanation. 



Two minima were observed in the vertical 

 salinity distribution during the spring and 

 summer months, one at about 200 meters and 

 the other at about 500 meters. This situation 

 was explained by Sverdrup (1942) as the re- 

 sult of the oceanic circulation. The upper mini- 

 mum was identified as the result of the North 

 Pacific Central Water spreading over the Sub- 

 arctic Water and the lower minimum as the 

 direct continuation of the Intermediate Water 

 flowing in the eastern gyral of the North Pa- 

 cific Ocean. The upper minimum is destroyed 

 during the winter months by the convective 

 mixing which increases the salinity. 



LITERATURE CITED 



Cochrane, J. D., 1950. Average Annual Heat Budget at 

 30° N., 140° W., Scripps Institution of Oceanography, 

 University of California, Progress Report No. 16. 



Husby, D. M., 1968. Oceanographic Observations, North 

 Pacific Ocean Station NOVEMBER, July 1966-Feb- 

 ruary 1967, U. S. Coast Guard Oceanographic Report 

 No. 18, CG-373-18. 



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

 U. S. Navy Hydrographic Olfice Pub. No. 614, pp. 114. 



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

 1942. The Oceans: Their Chemistry, Physics and 

 General Biology, Prentice-Hall, New York, pp. 1087. 



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

 Station Data, AGOR Cruise No. 056510, USNS 

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

 uscript No. 66-2, U. S. Naval Oceanographic Office, 

 Washington, D.C. 



Tully, J. P., 1964. "Oceanographic Regions and Process 

 in the Seasonal Zone of the North Pacific Ocean", 

 Studies on Oceanography. Edited by Kozo Yoshida, 

 University of Washington Press, pp. 68-74. 



U. S. Naval Oceanographic Office., 1968. Instruction 

 Manual for Oceanographic Observations, 3rd Edition, 

 Pub. No. 607. 



