57A125
Sea-ice thickness variability in the Storfjord, Svalbard
Archipelago
Stefan Hendricks, Sebastian Gerland, Lars Henrik Smedsrud,
Christian Haas, Andreas Aspmo Pfaffhuber
Corresponding author: Stefan Hendricks –
stefan.hendricks@awi.de
Sea-ice thickness observational data in Arctic fjords
exist mainly from the accessible fast-ice zones. Drifting sea ice, whether
advected into a fjord or locally formed, is subject to strong deformation
processes caused by the limitations of ice motion by the coastlines. Therefore,
the ice-thickness distribution within a fjord is dependent both on the overall
sea-ice situation in the bordering sea as well as dominant atmospheric
conditions. Here, we present the result of three field campaigns in the
Storfjord within the Svalbard Archipelago during spring of 2003, 2006 and 2007
with air- and ship-borne sea-ice thickness retrieval using electromagnetic
induction sounding. The Storfjord region is the location of a recurring coastal
polynya with high importance for northern Atlantic dense-water formation. In
each year, measurements were carried out in a time span of a few days. These
snapshots of the ice-thickness distribution are discussed in the context of
atmospheric circulation patterns and ice conditions in the adjacent Barents Sea.
Thin ice was observed in 2003 and 2007, when the major wind direction was
northeast in the vicinity of the data retrieval. In 2006, however, though data
were collected at a later period than the other years and the Barents Sea was
almost ice free, the Storfjord was covered completely with very thick sea ice.
The high mean thickness was the result of heavy deformation, caused by southerly
winds, even exceeding the mean thickness at the southern entrance of the
Storfjord in 2003, when the Barents Sea was covered with thick multi-year ice
originating from the central Arctic Ocean. The results of a 1-D sea-ice growth
model, forced with Barents Sea conditions, are compared with the observed
sea-ice thickness distributions in the individual years. The model shows higher
than average ice thickness in 2003 and substantially lower ice thickness in 2006
and 2007. These findings can be traced in the observed thickness distributions
in the fast-ice sections of all years and in the central Storfjord in 2007,
where the origin of the sea ice was either local or in the Barents Sea.
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