25 January 2002
Vol 295, Issue 5555

About The Cover

Cover image expansion

COVER In winter, a layer of frozen seawater with an area of more than 20 million km2 surrounds the Antarctic continent. In spring, this frozen cover begins to break up and in summer, only 4 million km2 of ice remain. The formation and melting of this huge ice mass drives climate, ocean circulation, and the ecosystem of the Southern Ocean. 641 [Photo: D. N. Thomas]