HYDROLOGY OF THE SOUTH ATLANTIC 



213 



To measure the seasonal changes in the temperature and sahnity of sub-Antarctic 

 water five stations have been used, WS 69, 138, 252, 318, and 432, which are fairly close 

 together in a position about 100 miles from the Antarctic convergence in approximately 

 52° 30' S, 52° 30' W. The results obtained from so few observations are necessarily only 



TEMPERATURE °C. 



MARCH JUNE 



SEPTEMBER DECEMBER 



MARCH 



SALINITY %o 



MARCH JUNE SEPTEMBER DECEMBER MARCH 



6'00 



S'OO- 



4-00 



3-00 



200 



34-30 



34-20 



34- 10 



34-00 



Fig. 21. The seasonal changes of the temperature and saUnity of sub- Antarctic water in 



52rs, szrw. 



approximate, but they are sufficient to show the nature of the changes which take place. 

 The four curves in the upper part of Fig. 21 show the change in temperature from month 

 to month of the water at the surface and at depths of 100, 400, and 600 m. They show 

 that the annual range of surface temperature, at a station about 100 miles north of the 

 convergence, is about 34° C: from 3-5° C in September to 6-9° C. at the end of 

 February. In the deeper layers the annual range decreases, until at 600 m. it is about 



