The Cosmonaut Sea Polynya
The Cosmonaut Sea off Antarctica
(~45E 65S) is a region in which anomalously low concentrations
of sea ice have been observed during the fall and winter months
(Comiso and Gordon 1987).
The most remarkable of these was during
the winter of 1980 when an embayment
of ice free open water formed in late June
and persisted for several weeks before being being enclosed by
sea ice and transformed into a polynya.
The polyna remained until mid August. At its maximum extent, there
was an approximate 130,000 sq kilometer region of open water totally
surrounded by ice in the depth of the Antarctic winter!
Several other polynyas have been observed
in the Cosmonaut Sea in the intervening 19 years but no sequence
of an embayment transforming into a polynya has been identified.
This year, we have identified another
embayment in the region in which an approximate 250,000 square
kilometer region of the Cosmonaut Sea was anomalously ice free.
It has recently been transformed into an open
Maximum area of ice free embayment during
June and July
in the Cosmonaut Sea region for each year
In 1999, we have observed the largest embayment
in the 21 years for which we have continuous data
black solid line: mean over the 21 year period
black dotted lines: one standard deviation
above and below the 21 year mean