Sea Ice Update
November 2016 set a record low for average ice extent. This reflects
this years’ unusually high temperatures, winds from the south and a warm ocean.
This November’s extent was the lowest on satellite record. The temperature was
so warm that for a period in November extent decreases by 50,000km2 per day as
opposed to the long-term average of 69,600km2 growth (NSIDC). Ice growth was
less extensive in the Kara, Barents, East Greenland and Chukchi seas and larger
in the Beaufort and East Siberian as well as Baffin Bay (NSIDC). The exceptional
warmth this year could signal a step beyond the tipping point only time will
tell. If a similar pattern of ocean and surface warming in the Arctic continues
next year, the sea ice as well as the Greenland Ice sheet could experience
rapid deterioration, flooding the global climate network with changes.
Continual and current updates can be tracked here: http://nsidc.org/arcticseaicenews/.
Background to the
Thermohaline
The thermohaline system is a part of the large-scale ocean
circulation that re-distributes heat across the globe. It relies on temperature
and salinity as drivers with the Arctic ocean and waters of Antarctica being
major areas of sinking. These are supported by warm surface currents such as
the Gulf Stream which transfer heat away from the equator in the Atlantic but
normally upwell in the Southern Ocean (Rahmstorf, 2003). The major benefit of
such an intricate system is the mixing that is allowed transforming the world’s
oceans into a single global system. Although its greatest asset, this also
means it is its greatest vulnerability. Failings along any point of the system
can causes a shutdown of the circulation inducing rapid shifts in regional
climates.
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