Weakening of the Geostrophic Component of the Gulf Stream: A Positive Feedback Loop on the Melting of the Arctic Ice Sheet
The North Atlantic gyre experiences both a significant temperature rise at high latitudes and a considerable weakening of the geostrophic component of the Gulf Stream, which is reflected by the 64-year fundamental gyral Rossby wave (GRW). This singular behavior compared to the South Atlantic and Sou...
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ftmdpi:oai:mdpi.com:/2077-1312/11/9/1689/ 2023-10-01T03:53:27+02:00 Weakening of the Geostrophic Component of the Gulf Stream: A Positive Feedback Loop on the Melting of the Arctic Ice Sheet Jean-Louis Pinault agris 2023-08-27 application/pdf https://doi.org/10.3390/jmse11091689 eng eng Multidisciplinary Digital Publishing Institute Physical Oceanography https://dx.doi.org/10.3390/jmse11091689 https://creativecommons.org/licenses/by/4.0/ Journal of Marine Science and Engineering Volume 11 Issue 9 Pages: 1689 Arctic amplification gyral Rossby waves north Atlantic gyre gulf stream drift current thermohaline circulation vertical mixing Text 2023 ftmdpi https://doi.org/10.3390/jmse11091689 2023-09-03T23:52:40Z The North Atlantic gyre experiences both a significant temperature rise at high latitudes and a considerable weakening of the geostrophic component of the Gulf Stream, which is reflected by the 64-year fundamental gyral Rossby wave (GRW). This singular behavior compared to the South Atlantic and South Indian Ocean gyres highlights a feedback loop of Arctic ice sheet melting on mid-latitude Atlantic Ocean temperature. The warming of the northern oceanic gyre at high latitudes due to the retreat of Arctic ice sheet via the Labrador Current decreases the thermal gradient between the high and low latitudes of the north Atlantic gyre. This results in a weakening of the geostrophic forces at the basin scale and a reduction in the amplitude of the GRWs. Reducing the amplitude of the variation of the upward and downward movement of the pycnocline modifies air–sea interactions, weakening vertical mixing as well as the evaporation processes and the departure of latent heat when the pycnocline rises. The resulting thermal anomaly stretching along the Gulf Stream from where it leaves the American continent is partly transferred to the Arctic sea ice via the drift current and thermohaline circulation, which contributes to the retreat of the ice sheet, and the closing of the feedback loop. The 64-year-period GRW should disappear around 2050 if its damping continues linearly, favoring an increasingly rapid warming of the ocean at mid-latitudes. These interactions are less acute in the southern hemisphere due to the circumpolar current. Text Arctic Ice Sheet North Atlantic Sea ice MDPI Open Access Publishing Arctic Indian Journal of Marine Science and Engineering 11 9 1689 |
institution |
Open Polar |
collection |
MDPI Open Access Publishing |
op_collection_id |
ftmdpi |
language |
English |
topic |
Arctic amplification gyral Rossby waves north Atlantic gyre gulf stream drift current thermohaline circulation vertical mixing |
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Arctic amplification gyral Rossby waves north Atlantic gyre gulf stream drift current thermohaline circulation vertical mixing Jean-Louis Pinault Weakening of the Geostrophic Component of the Gulf Stream: A Positive Feedback Loop on the Melting of the Arctic Ice Sheet |
topic_facet |
Arctic amplification gyral Rossby waves north Atlantic gyre gulf stream drift current thermohaline circulation vertical mixing |
description |
The North Atlantic gyre experiences both a significant temperature rise at high latitudes and a considerable weakening of the geostrophic component of the Gulf Stream, which is reflected by the 64-year fundamental gyral Rossby wave (GRW). This singular behavior compared to the South Atlantic and South Indian Ocean gyres highlights a feedback loop of Arctic ice sheet melting on mid-latitude Atlantic Ocean temperature. The warming of the northern oceanic gyre at high latitudes due to the retreat of Arctic ice sheet via the Labrador Current decreases the thermal gradient between the high and low latitudes of the north Atlantic gyre. This results in a weakening of the geostrophic forces at the basin scale and a reduction in the amplitude of the GRWs. Reducing the amplitude of the variation of the upward and downward movement of the pycnocline modifies air–sea interactions, weakening vertical mixing as well as the evaporation processes and the departure of latent heat when the pycnocline rises. The resulting thermal anomaly stretching along the Gulf Stream from where it leaves the American continent is partly transferred to the Arctic sea ice via the drift current and thermohaline circulation, which contributes to the retreat of the ice sheet, and the closing of the feedback loop. The 64-year-period GRW should disappear around 2050 if its damping continues linearly, favoring an increasingly rapid warming of the ocean at mid-latitudes. These interactions are less acute in the southern hemisphere due to the circumpolar current. |
format |
Text |
author |
Jean-Louis Pinault |
author_facet |
Jean-Louis Pinault |
author_sort |
Jean-Louis Pinault |
title |
Weakening of the Geostrophic Component of the Gulf Stream: A Positive Feedback Loop on the Melting of the Arctic Ice Sheet |
title_short |
Weakening of the Geostrophic Component of the Gulf Stream: A Positive Feedback Loop on the Melting of the Arctic Ice Sheet |
title_full |
Weakening of the Geostrophic Component of the Gulf Stream: A Positive Feedback Loop on the Melting of the Arctic Ice Sheet |
title_fullStr |
Weakening of the Geostrophic Component of the Gulf Stream: A Positive Feedback Loop on the Melting of the Arctic Ice Sheet |
title_full_unstemmed |
Weakening of the Geostrophic Component of the Gulf Stream: A Positive Feedback Loop on the Melting of the Arctic Ice Sheet |
title_sort |
weakening of the geostrophic component of the gulf stream: a positive feedback loop on the melting of the arctic ice sheet |
publisher |
Multidisciplinary Digital Publishing Institute |
publishDate |
2023 |
url |
https://doi.org/10.3390/jmse11091689 |
op_coverage |
agris |
geographic |
Arctic Indian |
geographic_facet |
Arctic Indian |
genre |
Arctic Ice Sheet North Atlantic Sea ice |
genre_facet |
Arctic Ice Sheet North Atlantic Sea ice |
op_source |
Journal of Marine Science and Engineering Volume 11 Issue 9 Pages: 1689 |
op_relation |
Physical Oceanography https://dx.doi.org/10.3390/jmse11091689 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3390/jmse11091689 |
container_title |
Journal of Marine Science and Engineering |
container_volume |
11 |
container_issue |
9 |
container_start_page |
1689 |
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1778520049121755136 |