Northern Hemisphere Winter Air Temperature Patterns and Their Associated Atmospheric and Ocean Conditions
The Northern Hemisphere (NH) has experienced winter Arctic warming and continental cooling in recent decades, but the dominant patterns in winter surface air temperature (SAT) are not well understood. Here, a self-organizing map (SOM) analysis is performed to identify the leading patterns in winter...
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ftosti:oai:osti.gov:1802436 2023-07-30T04:01:34+02:00 Northern Hemisphere Winter Air Temperature Patterns and Their Associated Atmospheric and Ocean Conditions Deng, Jiechun Dai, Aiguo Chyi, Dorina 2022-09-27 application/pdf http://www.osti.gov/servlets/purl/1802436 https://www.osti.gov/biblio/1802436 https://doi.org/10.1175/jcli-d-19-0533.1 unknown http://www.osti.gov/servlets/purl/1802436 https://www.osti.gov/biblio/1802436 https://doi.org/10.1175/jcli-d-19-0533.1 doi:10.1175/jcli-d-19-0533.1 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS 2022 ftosti https://doi.org/10.1175/jcli-d-19-0533.1 2023-07-11T10:04:50Z The Northern Hemisphere (NH) has experienced winter Arctic warming and continental cooling in recent decades, but the dominant patterns in winter surface air temperature (SAT) are not well understood. Here, a self-organizing map (SOM) analysis is performed to identify the leading patterns in winter daily SAT fields from 1979 to 2018, and their associated atmospheric and ocean conditions are also examined. Three distinct winter SAT patterns with two phases of nearly opposite signs and a time scale of 7–12 days are found: one pattern exhibits concurrent SAT anomalies of the same sign over North America (NA) and northern Eurasia, while the other two patterns show SAT anomalies of opposite signs between, respectively, NA and the Bering Sea, and the Kara Sea and East Asia (EA). Winter SAT variations may arise from changes in the SOM frequencies. Specifically, the observed increasing trends of winter cold extremes over NA, central Eurasia, and EA during 1998–2013 can be understood as a result of the increasing occurrences of some specific SAT patterns. These SOMs are closely related to poleward advection of midlatitude warm air and equatorward movements of polar cold airmass. These meridional displacements of cold and warm airmasses cause concurrent anomalies over different regions not only in SAT but also in water vapor and surface downward longwave radiation. Anomalous sea surface temperatures in the tropical Pacific, midlatitude North Pacific, and North Atlantic and anomalous Arctic sea ice concentrations also concur to support and maintain the anomalous atmospheric circulation that causes the SAT anomalies. Other/Unknown Material Arctic Bering Sea Kara Sea North Atlantic Sea ice SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Arctic Bering Sea Kara Sea Pacific Journal of Climate 33 14 6165 6186 |
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SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
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ftosti |
language |
unknown |
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72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS |
spellingShingle |
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS Deng, Jiechun Dai, Aiguo Chyi, Dorina Northern Hemisphere Winter Air Temperature Patterns and Their Associated Atmospheric and Ocean Conditions |
topic_facet |
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS |
description |
The Northern Hemisphere (NH) has experienced winter Arctic warming and continental cooling in recent decades, but the dominant patterns in winter surface air temperature (SAT) are not well understood. Here, a self-organizing map (SOM) analysis is performed to identify the leading patterns in winter daily SAT fields from 1979 to 2018, and their associated atmospheric and ocean conditions are also examined. Three distinct winter SAT patterns with two phases of nearly opposite signs and a time scale of 7–12 days are found: one pattern exhibits concurrent SAT anomalies of the same sign over North America (NA) and northern Eurasia, while the other two patterns show SAT anomalies of opposite signs between, respectively, NA and the Bering Sea, and the Kara Sea and East Asia (EA). Winter SAT variations may arise from changes in the SOM frequencies. Specifically, the observed increasing trends of winter cold extremes over NA, central Eurasia, and EA during 1998–2013 can be understood as a result of the increasing occurrences of some specific SAT patterns. These SOMs are closely related to poleward advection of midlatitude warm air and equatorward movements of polar cold airmass. These meridional displacements of cold and warm airmasses cause concurrent anomalies over different regions not only in SAT but also in water vapor and surface downward longwave radiation. Anomalous sea surface temperatures in the tropical Pacific, midlatitude North Pacific, and North Atlantic and anomalous Arctic sea ice concentrations also concur to support and maintain the anomalous atmospheric circulation that causes the SAT anomalies. |
author |
Deng, Jiechun Dai, Aiguo Chyi, Dorina |
author_facet |
Deng, Jiechun Dai, Aiguo Chyi, Dorina |
author_sort |
Deng, Jiechun |
title |
Northern Hemisphere Winter Air Temperature Patterns and Their Associated Atmospheric and Ocean Conditions |
title_short |
Northern Hemisphere Winter Air Temperature Patterns and Their Associated Atmospheric and Ocean Conditions |
title_full |
Northern Hemisphere Winter Air Temperature Patterns and Their Associated Atmospheric and Ocean Conditions |
title_fullStr |
Northern Hemisphere Winter Air Temperature Patterns and Their Associated Atmospheric and Ocean Conditions |
title_full_unstemmed |
Northern Hemisphere Winter Air Temperature Patterns and Their Associated Atmospheric and Ocean Conditions |
title_sort |
northern hemisphere winter air temperature patterns and their associated atmospheric and ocean conditions |
publishDate |
2022 |
url |
http://www.osti.gov/servlets/purl/1802436 https://www.osti.gov/biblio/1802436 https://doi.org/10.1175/jcli-d-19-0533.1 |
geographic |
Arctic Bering Sea Kara Sea Pacific |
geographic_facet |
Arctic Bering Sea Kara Sea Pacific |
genre |
Arctic Bering Sea Kara Sea North Atlantic Sea ice |
genre_facet |
Arctic Bering Sea Kara Sea North Atlantic Sea ice |
op_relation |
http://www.osti.gov/servlets/purl/1802436 https://www.osti.gov/biblio/1802436 https://doi.org/10.1175/jcli-d-19-0533.1 doi:10.1175/jcli-d-19-0533.1 |
op_doi |
https://doi.org/10.1175/jcli-d-19-0533.1 |
container_title |
Journal of Climate |
container_volume |
33 |
container_issue |
14 |
container_start_page |
6165 |
op_container_end_page |
6186 |
_version_ |
1772812345895026688 |