310 POLAR PROBLEMS 



EXTREME TEMPERATURES 



The minimum temperature may be as low as -20° in Tierra del 

 Fuego. 



At the South Orkneys and at the Weddell Sea stations minima 

 of -41° have been attained. 



On the western coast of Graham Land the temperatures are not so 

 low. The minimum at Wandel Island is -34°, and at Petermann 

 Island in 1909 the thermometer did not go below -23.9°, which is 

 remarkable for a polar station. 



The minimum of the Belgica was -43.1°. 



All these temperatures are not extraordinarily low — in the Arctic 

 as well as in the Antarctic temperatures of —60° have been observed. 

 The open sea, which is never far away in the American quadrant of the 

 Antarctic, exercises a noticeable tempering influence on the climate of 

 the region. 



The Wind 



direction of the wind 



In general, although it is always rather arbitrary to try to sum- 

 marize the character of the winds in regions where they are so change- 

 able, it may be said that the stations at Tierra del Fuego, the Falkland 

 Islands, and South Georgia are included in the general westward 

 wind drift. 



In the Antarctic proper the winds differ from one station to 

 another: at the South Orkneys the predominating winds blow from 

 the west ; at Snow Hill from the southwest ; at Wandel and Petermann 

 Islands from the northeast; in the region traversed by the Belgica 

 on her drift, from easterly directions in summer and westerly in 

 winter; in the region where the Deutschland drifted, from south and 

 southeast in latitudes lower than 70° and rather definitely from the 

 east in summer in latitudes higher than 70°. 



As is well known, mean isobars run very nearly parallel to the mean 

 direction of the wind. The direction of the winds along the drift 

 routes of the Belgica and the Deutschland in the summer show that 

 there are two areas of relatively low pressure over Weddell Sea and 

 Bellingshausen Sea respectively and that the Antarctic anticyclone 

 is met with in about latitude 70°, as is indicated directly by the 

 observations of atmospheric pressure themselves. But in winter the 

 distribution of pressure seems more complex. In Weddell Sea, as far 

 as latitude 69°, there is no evidence that pressure increases with 

 latitude. The observed winds on the contrary show that the low pres- 

 sures are always situated to the south, producing southwest winds 

 at Snow Hill, west-southwest at the South Orkneys, northwest at 

 South Georgia, and southeast on board the Deutschland in latitude 69°. 



