The Melting of Ice in the Arctic Ocean: The Influence of Double-Diffusive Transport of Heat from Below
This investigation was originally prompted by two oceanographic observations: an increased rate of melting of sea ice in the Arctic Ocean, and the advance of an anomalously warm tongue of Atlantic water intruding across the Arctic below the halocline over the past few decades.Aseries of laboratory m...
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ftanucanberra:oai:digitalcollections.anu.edu.au:1885/39389 2023-05-15T14:29:19+02:00 The Melting of Ice in the Arctic Ocean: The Influence of Double-Diffusive Transport of Heat from Below Turner, John (Stewart) 2015-12-10T21:56:21Z http://hdl.handle.net/1885/39389 unknown American Meteorological Society 0022-3670 http://hdl.handle.net/1885/39389 Journal of Physical Oceanography Journal article 2015 ftanucanberra 2015-12-21T23:29:55Z This investigation was originally prompted by two oceanographic observations: an increased rate of melting of sea ice in the Arctic Ocean, and the advance of an anomalously warm tongue of Atlantic water intruding across the Arctic below the halocline over the past few decades.Aseries of laboratory model experiments has previously been carried out to explore the possibility that the extra heating at depth could be responsible for the enhanced melting rate. These experiments have demonstrated that a one-dimensional heat flux from below through a series of double-diffusive layers can in principle lead to faster melting of floating ice. However, it is now essential to test these ideas quantitatively under ocean conditions and to compare the results with other possible mechanisms of melting. Asimple calculation shows that there is enough heat in the intruding Atlantic water to melt all the ice in the Arctic in a few years if all the heat could be brought to the surface in this time. The vertical double-diffusive transport of heat is slower than this, but it is large enough to make a substantial contribution to the increased rate of melting over the last three or four decades. Another proposed mechanism for melting is the solar input to the surface mixed layer from the atmosphere. In particular years when detailed measurements and calculations have been made, this atmospheric input can explain both the seasonal cyclic behavior of ice and the increased melting rate. Given the large heat content in the intruding Atlantic layer, however, it seems worth exploring further other advective two-dimensional mechanisms that could transport this heat upward more rapidly than the purely vertical double-diffusive convection. For example, dense salty water produced by freezing on the shelves around the Arctic Basin could flow down the slope and penetrate through the halocline, thus mixing with the warm water and bringing it to the surface. Article in Journal/Newspaper Arctic Basin Arctic Arctic Ocean Sea ice Australian National University: ANU Digital Collections Arctic Arctic Ocean |
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Australian National University: ANU Digital Collections |
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This investigation was originally prompted by two oceanographic observations: an increased rate of melting of sea ice in the Arctic Ocean, and the advance of an anomalously warm tongue of Atlantic water intruding across the Arctic below the halocline over the past few decades.Aseries of laboratory model experiments has previously been carried out to explore the possibility that the extra heating at depth could be responsible for the enhanced melting rate. These experiments have demonstrated that a one-dimensional heat flux from below through a series of double-diffusive layers can in principle lead to faster melting of floating ice. However, it is now essential to test these ideas quantitatively under ocean conditions and to compare the results with other possible mechanisms of melting. Asimple calculation shows that there is enough heat in the intruding Atlantic water to melt all the ice in the Arctic in a few years if all the heat could be brought to the surface in this time. The vertical double-diffusive transport of heat is slower than this, but it is large enough to make a substantial contribution to the increased rate of melting over the last three or four decades. Another proposed mechanism for melting is the solar input to the surface mixed layer from the atmosphere. In particular years when detailed measurements and calculations have been made, this atmospheric input can explain both the seasonal cyclic behavior of ice and the increased melting rate. Given the large heat content in the intruding Atlantic layer, however, it seems worth exploring further other advective two-dimensional mechanisms that could transport this heat upward more rapidly than the purely vertical double-diffusive convection. For example, dense salty water produced by freezing on the shelves around the Arctic Basin could flow down the slope and penetrate through the halocline, thus mixing with the warm water and bringing it to the surface. |
format |
Article in Journal/Newspaper |
author |
Turner, John (Stewart) |
spellingShingle |
Turner, John (Stewart) The Melting of Ice in the Arctic Ocean: The Influence of Double-Diffusive Transport of Heat from Below |
author_facet |
Turner, John (Stewart) |
author_sort |
Turner, John (Stewart) |
title |
The Melting of Ice in the Arctic Ocean: The Influence of Double-Diffusive Transport of Heat from Below |
title_short |
The Melting of Ice in the Arctic Ocean: The Influence of Double-Diffusive Transport of Heat from Below |
title_full |
The Melting of Ice in the Arctic Ocean: The Influence of Double-Diffusive Transport of Heat from Below |
title_fullStr |
The Melting of Ice in the Arctic Ocean: The Influence of Double-Diffusive Transport of Heat from Below |
title_full_unstemmed |
The Melting of Ice in the Arctic Ocean: The Influence of Double-Diffusive Transport of Heat from Below |
title_sort |
melting of ice in the arctic ocean: the influence of double-diffusive transport of heat from below |
publisher |
American Meteorological Society |
publishDate |
2015 |
url |
http://hdl.handle.net/1885/39389 |
geographic |
Arctic Arctic Ocean |
geographic_facet |
Arctic Arctic Ocean |
genre |
Arctic Basin Arctic Arctic Ocean Sea ice |
genre_facet |
Arctic Basin Arctic Arctic Ocean Sea ice |
op_source |
Journal of Physical Oceanography |
op_relation |
0022-3670 http://hdl.handle.net/1885/39389 |
_version_ |
1766303362312044544 |