258 



Ice in the Sea 



Fig. 115. Average extent of sea ice (mean drift ice limit) in the Northern Hemisphere for 



summer and winter: 



mm^ 



AAA 



m///m 



°o°o° 



AVERAGE DISTRIBUTION OF 



Polar ice coverage closed in summer (about beginning of September) 

 Brocken polar ice coverage in summer (about beginning of September) 

 Southernmost iceberg limit in summer (May to September) 

 Closed polar ice coverage in winter (March to April) 

 Brocken polar ice coverage in winter (March to April) 

 Southernmost iceberg limit in winter (October to March) 

 Closed ice on inland seas and lakes in winter (February to March) 

 Brocken ice on inland seas and lakes in winter (February to March) 



without any large meridional irregularities. In the Northern Hemisphere, on the 

 other hand, the continents and the eccentrical position of the large polar icelands 

 confine the ice field on all sides, and allow warm ocean currents to enter at only one 

 gate, between Iceland and Scandinavia where the warm Atlantic current pushes the 

 limits of drift ice back to the northern coast of Spitzbergen and into the inner parts 

 of the Barents Sea. 



