Abstract

Antarctic sea-ice is potentially one
of
the most
sensitive global warming indicators. Some re-
cent studies using coupled ocean-atmosphere
general circulation models suggest that C0,-
induced warming and concomitant sea-ice re-
duction might be less marked than in the Arctic
(Gordon and O’Farrell 1997); certainly the
moderating influence of the Southern Ocean as
a heat store must be considered. On the other
hand, because Antarctic sea-ice is generally
much thinner (typically 0.3-1.0m) than its
boreal counterpart (about 3.0m), changes in its
extent are possibly more temperature-sensitive
than in the Arctic (Rind zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
et zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
al.
1997). A twofold
response involving a decrease in sea-ice extent
near the Antarctic Peninsula zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA
(AP)
and a more
general increase elsewhere around Antarctica
might result from an enhanced maritime-conti-
nental climate regime (Stammerjohn and
Smith 1997). According to this idea, for which
there is some observational evidence, increased
precipitation may freshen the Southern Ocean
surface layer, lower the sea surface temperature
(SST) and strengthen the prevailing westerly
winds in the Southern Circumpolar Trough
(polar cyclone belt)
-
the position of which may
also change.