Pacific Decadal Oscillation modulates the Arctic sea-ice loss influence on the mid-latitude atmospheric circulation in winter
The modulation of the winter impacts of Arctic sea-ice loss by the Pacific Decadal Oscillation (PDO) is investigated in the IPSL-CM6A-LR ocean–atmosphere general circulation model. Ensembles of simulations are performed with constrained sea-ice concentration following the Polar Amplification Model I...
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ftcopernicus:oai:publications.copernicus.org:egusphere102079 2023-05-15T13:15:04+02:00 Pacific Decadal Oscillation modulates the Arctic sea-ice loss influence on the mid-latitude atmospheric circulation in winter Simon, Amélie Gastineau, Guillaume Frankignoul, Claude Lapin, Vladimir Ortega, Pablo 2022-08-04 application/pdf https://doi.org/10.5194/egusphere-2022-69 https://egusphere.copernicus.org/preprints/2022/egusphere-2022-69/ eng eng doi:10.5194/egusphere-2022-69 https://egusphere.copernicus.org/preprints/2022/egusphere-2022-69/ eISSN: Text 2022 ftcopernicus https://doi.org/10.5194/egusphere-2022-69 2022-08-08T16:22:56Z The modulation of the winter impacts of Arctic sea-ice loss by the Pacific Decadal Oscillation (PDO) is investigated in the IPSL-CM6A-LR ocean–atmosphere general circulation model. Ensembles of simulations are performed with constrained sea-ice concentration following the Polar Amplification Model Intercomparison Project (PAMIP) and initial conditions sampling warm and cold phases of the PDO. Using a general linear model, we estimate the simulated winter impact of sea-ice loss, PDO and their combined effects. On the one hand, a negative North Atlantic Oscillation (NAO)-like pattern appears in response to sea-ice loss together with a modest deepening of the Aleutian Low. On the other hand, a warm PDO phase induces a large positive Pacific–North America pattern, as well as a small negative Arctic Oscillation pattern. Both sea-ice loss and warm PDO responses are associated with a weakening of the poleward flank of the eddy-driven jet, an intensification of the subtropical jet and a weakening of the stratospheric polar vortex. These effects are partly additive; the warm PDO phase therefore enhances the response to sea-ice loss, while the cold PDO phase reduces it. However, the effects of PDO and sea-ice loss are also partly non-additive, with the interaction between both signals being slightly destructive. This results in small damping of the PDO teleconnections under sea-ice loss conditions, especially in the stratosphere. The sea-ice loss responses are compared to those obtained with the same model in atmosphere-only simulations, where sea-ice loss does not significantly alter the stratospheric polar vortex. Text aleutian low Arctic North Atlantic North Atlantic oscillation Sea ice Copernicus Publications: E-Journals Arctic Pacific |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
The modulation of the winter impacts of Arctic sea-ice loss by the Pacific Decadal Oscillation (PDO) is investigated in the IPSL-CM6A-LR ocean–atmosphere general circulation model. Ensembles of simulations are performed with constrained sea-ice concentration following the Polar Amplification Model Intercomparison Project (PAMIP) and initial conditions sampling warm and cold phases of the PDO. Using a general linear model, we estimate the simulated winter impact of sea-ice loss, PDO and their combined effects. On the one hand, a negative North Atlantic Oscillation (NAO)-like pattern appears in response to sea-ice loss together with a modest deepening of the Aleutian Low. On the other hand, a warm PDO phase induces a large positive Pacific–North America pattern, as well as a small negative Arctic Oscillation pattern. Both sea-ice loss and warm PDO responses are associated with a weakening of the poleward flank of the eddy-driven jet, an intensification of the subtropical jet and a weakening of the stratospheric polar vortex. These effects are partly additive; the warm PDO phase therefore enhances the response to sea-ice loss, while the cold PDO phase reduces it. However, the effects of PDO and sea-ice loss are also partly non-additive, with the interaction between both signals being slightly destructive. This results in small damping of the PDO teleconnections under sea-ice loss conditions, especially in the stratosphere. The sea-ice loss responses are compared to those obtained with the same model in atmosphere-only simulations, where sea-ice loss does not significantly alter the stratospheric polar vortex. |
format |
Text |
author |
Simon, Amélie Gastineau, Guillaume Frankignoul, Claude Lapin, Vladimir Ortega, Pablo |
spellingShingle |
Simon, Amélie Gastineau, Guillaume Frankignoul, Claude Lapin, Vladimir Ortega, Pablo Pacific Decadal Oscillation modulates the Arctic sea-ice loss influence on the mid-latitude atmospheric circulation in winter |
author_facet |
Simon, Amélie Gastineau, Guillaume Frankignoul, Claude Lapin, Vladimir Ortega, Pablo |
author_sort |
Simon, Amélie |
title |
Pacific Decadal Oscillation modulates the Arctic sea-ice loss influence on the mid-latitude atmospheric circulation in winter |
title_short |
Pacific Decadal Oscillation modulates the Arctic sea-ice loss influence on the mid-latitude atmospheric circulation in winter |
title_full |
Pacific Decadal Oscillation modulates the Arctic sea-ice loss influence on the mid-latitude atmospheric circulation in winter |
title_fullStr |
Pacific Decadal Oscillation modulates the Arctic sea-ice loss influence on the mid-latitude atmospheric circulation in winter |
title_full_unstemmed |
Pacific Decadal Oscillation modulates the Arctic sea-ice loss influence on the mid-latitude atmospheric circulation in winter |
title_sort |
pacific decadal oscillation modulates the arctic sea-ice loss influence on the mid-latitude atmospheric circulation in winter |
publishDate |
2022 |
url |
https://doi.org/10.5194/egusphere-2022-69 https://egusphere.copernicus.org/preprints/2022/egusphere-2022-69/ |
geographic |
Arctic Pacific |
geographic_facet |
Arctic Pacific |
genre |
aleutian low Arctic North Atlantic North Atlantic oscillation Sea ice |
genre_facet |
aleutian low Arctic North Atlantic North Atlantic oscillation Sea ice |
op_source |
eISSN: |
op_relation |
doi:10.5194/egusphere-2022-69 https://egusphere.copernicus.org/preprints/2022/egusphere-2022-69/ |
op_doi |
https://doi.org/10.5194/egusphere-2022-69 |
_version_ |
1766266818840756224 |