Shelf-basin exchange in the Laptev Sea in the warming climate: a model study
Shelf-basin exchange in the Laptev Sea in the warming climate: a model study
GCM-based forecast simulations predict continuously increasing seasonality of the sea ice cover and an almost ice-free, summer-time, Arctic Ocean within several decades from the present. In this study we use a primitive equation ocean model: NEMO, coupled with the sea ice model LIM2, to test the hypothesis that under such an increased range in seasonal ice cover the intensity of shelf-basin water exchange will significantly increase. We use the simulated results for the Laptev Sea from a global model run 1958–2007 and compare results for two years with anomalously high and low summer sea ice extents: 1986–1987 and 2006–2007. The shelf–basin fluxes of volume, heat and salt during specific seasons are evaluated and attributed to plausible driving processes, with particular attention to dense water cascading. Analyses of the model temperature distribution at the depth of the intermediate maximum, associated with Atlantic Water, have shown a marked increase of the amount of the local origin cold water in late winter 2007 in the region, where dense water typically appears as a result of its formation on the shelf and subsequent downslope leakage. Calculation of the shelf-basin exchange during March-May in both years confirmed a substantial increase (a factor of two) of fluxes in “ice-free” 2007 compared to the “icy” 1987. According to several past model studies, dense water production on Arctic shelves in winter driven by ice freezing and brine rejection is not likely to cease in a warmer climate, but rather to increase. There is also observational evidence that cascading in the seasonally ice covered seas (e.g. the Barents Sea) is much more efficient than it is in the permanently ice covered Arctic Ocean, which supports these model results.
Shelf-basin exchange, Dense water cascading, Arctic Ocean, Sea ice, Climate change
254-280
Ivanov, Vladimir
39517f5f-7b2b-484a-957b-57958e6f0da1
Maslov, Pavel
e7ed2a22-c937-4075-a289-c15c321fac7f
Aksenov, Yevgeny
1d277047-06f6-4893-8bcf-c2817a9c848e
Coward, Andrew
53b78140-2e65-476a-b287-e8384a65224b
2015
Ivanov, Vladimir
39517f5f-7b2b-484a-957b-57958e6f0da1
Maslov, Pavel
e7ed2a22-c937-4075-a289-c15c321fac7f
Aksenov, Yevgeny
1d277047-06f6-4893-8bcf-c2817a9c848e
Coward, Andrew
53b78140-2e65-476a-b287-e8384a65224b
Ivanov, Vladimir, Maslov, Pavel, Aksenov, Yevgeny and Coward, Andrew
(2015)
Shelf-basin exchange in the Laptev Sea in the warming climate: a model study.
Geophysical & Astrophysical Fluid Dynamics, 109 (3), .
(doi:10.1080/03091929.2015.1025776).
Abstract
GCM-based forecast simulations predict continuously increasing seasonality of the sea ice cover and an almost ice-free, summer-time, Arctic Ocean within several decades from the present. In this study we use a primitive equation ocean model: NEMO, coupled with the sea ice model LIM2, to test the hypothesis that under such an increased range in seasonal ice cover the intensity of shelf-basin water exchange will significantly increase. We use the simulated results for the Laptev Sea from a global model run 1958–2007 and compare results for two years with anomalously high and low summer sea ice extents: 1986–1987 and 2006–2007. The shelf–basin fluxes of volume, heat and salt during specific seasons are evaluated and attributed to plausible driving processes, with particular attention to dense water cascading. Analyses of the model temperature distribution at the depth of the intermediate maximum, associated with Atlantic Water, have shown a marked increase of the amount of the local origin cold water in late winter 2007 in the region, where dense water typically appears as a result of its formation on the shelf and subsequent downslope leakage. Calculation of the shelf-basin exchange during March-May in both years confirmed a substantial increase (a factor of two) of fluxes in “ice-free” 2007 compared to the “icy” 1987. According to several past model studies, dense water production on Arctic shelves in winter driven by ice freezing and brine rejection is not likely to cease in a warmer climate, but rather to increase. There is also observational evidence that cascading in the seasonally ice covered seas (e.g. the Barents Sea) is much more efficient than it is in the permanently ice covered Arctic Ocean, which supports these model results.
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GGAF-2014-0012-combined.pdf
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Published date: 2015
Keywords:
Shelf-basin exchange, Dense water cascading, Arctic Ocean, Sea ice, Climate change
Organisations:
Marine Systems Modelling
Identifiers
Local EPrints ID: 386579
URI: http://eprints.soton.ac.uk/id/eprint/386579
ISSN: 0309-1929
PURE UUID: c2312557-ae5c-462a-a6fa-d0d060da43e9
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Date deposited: 28 Jan 2016 14:12
Last modified: 15 Mar 2024 05:23
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Contributors
Author:
Vladimir Ivanov
Author:
Pavel Maslov
Author:
Yevgeny Aksenov
Author:
Andrew Coward
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