Do Greenland's outlet glaciers care about the ocean and
viceversa?
Fiamma Straneo
Abstract:
The unexpected and widespread acceleration of outlet glaciers in
Greenland over the last decade has contributed to a doubling of the
ice sheet's contribution to sea level rise. The mechanisms behind the
acceleration are unclear but there is increasing evidence that warming
of ocean waters coming in contact with the glaciers may have played a
role. This, in turn, would imply that the ocean can impact the
variability of the Greenland Ice Sheet on decadal
timescales. Regardless of the ocean's role in triggering the recent
glaciers' acceleration - ocean-driven melting at the ice sheet's
margins has recently emerged as a significant term in the ice sheet's
mass balance. Yet our understanding of the oceanic, atmospheric and
glaciological processes controlling the properties of the waters
reaching the glaciers and their variability is limited and this
physics is either absent or crudely represented in ice sheet, glacier
and climate models. Here, I will present recent observations from
several major glacial fjords systems in East Greenland (some which
have recently accelerated and some which have not) and discuss the
first order dynamics that have emerged from these surveys. Amongst the
relevant processes - I will argue that outlet glaciers are sensitive
to the variability of both Arctic and Atlantic waters circulating
around Greenland as well as synoptic weather systems which modulate
the fjord/shelf exchange. Finally, I will argue that the shape of
terminus, and hence the stability, of Greenland's glaciers is strongly
controlled by large scale ocean circulation.
Background Reading:
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Rapid Circulation of warm subtropical waters in a major glacial fjord
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