Indicators and trends of polar cold airmass
Trends and variations in the amount of cold airmass in the Arctic and the Northern Hemisphere are evaluated for the 60 year period, 1959–2018. The two indicators are (1) polar cold air mass (PCAM), which is the amount of air below a potential temperature threshold, and (2) negative heat content (NHC...
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ftunivbergen:oai:bora.uib.no:11250/2726660 2023-05-15T14:57:54+02:00 Indicators and trends of polar cold airmass Kanno, Yuki Walsh, John E. Abdillah, Muhammad R Yamaguchi, Junpei Iwasaki, Toshiki 2019 application/pdf https://hdl.handle.net/11250/2726660 https://doi.org/10.1088/1748-9326/aaf42b eng eng IOP Publishing urn:issn:1748-9326 https://hdl.handle.net/11250/2726660 https://doi.org/10.1088/1748-9326/aaf42b cristin:1800000 Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no Copyright 2019 The Author(s). Environmental Research Letters 14 2 1-11 Journal article Peer reviewed 2019 ftunivbergen https://doi.org/10.1088/1748-9326/aaf42b 2023-03-14T17:42:19Z Trends and variations in the amount of cold airmass in the Arctic and the Northern Hemisphere are evaluated for the 60 year period, 1959–2018. The two indicators are (1) polar cold air mass (PCAM), which is the amount of air below a potential temperature threshold, and (2) negative heat content (NHC), which includes a weighting by coldness. Because the metrics of coldness are based on multiple layers in the atmosphere, they provide a more comprehensive framework for assessment of warming than is provided by surface air temperatures alone. The negative trends of PCAM and NHC are stronger (as a % per decade) when the threshold is 245 K rather than 280 K, indicating that the loss of extremely cold air is happening at a faster rate than the loss of moderately cold air. The loss of cold air has accelerated, as the most rapid loss of NHC has occurred in recent decades (1989–2018). The spatial patterns of the trends of PCAM and NHC provide another manifestation of Arctic amplification. Of the various teleconnection indices, the Atlantic Multidecadal Oscillation shows the strongest correlations with the spatially integrated metrics of moderate coldness. Several Pacific indices also correlate significantly with these indicators. However, the amount of extremely cold air mass does not correlate significantly with the indices of internal variability used here. publishedVersion Article in Journal/Newspaper Arctic University of Bergen: Bergen Open Research Archive (BORA-UiB) Arctic Pacific Environmental Research Letters 14 2 025006 |
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Open Polar |
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University of Bergen: Bergen Open Research Archive (BORA-UiB) |
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ftunivbergen |
language |
English |
description |
Trends and variations in the amount of cold airmass in the Arctic and the Northern Hemisphere are evaluated for the 60 year period, 1959–2018. The two indicators are (1) polar cold air mass (PCAM), which is the amount of air below a potential temperature threshold, and (2) negative heat content (NHC), which includes a weighting by coldness. Because the metrics of coldness are based on multiple layers in the atmosphere, they provide a more comprehensive framework for assessment of warming than is provided by surface air temperatures alone. The negative trends of PCAM and NHC are stronger (as a % per decade) when the threshold is 245 K rather than 280 K, indicating that the loss of extremely cold air is happening at a faster rate than the loss of moderately cold air. The loss of cold air has accelerated, as the most rapid loss of NHC has occurred in recent decades (1989–2018). The spatial patterns of the trends of PCAM and NHC provide another manifestation of Arctic amplification. Of the various teleconnection indices, the Atlantic Multidecadal Oscillation shows the strongest correlations with the spatially integrated metrics of moderate coldness. Several Pacific indices also correlate significantly with these indicators. However, the amount of extremely cold air mass does not correlate significantly with the indices of internal variability used here. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Kanno, Yuki Walsh, John E. Abdillah, Muhammad R Yamaguchi, Junpei Iwasaki, Toshiki |
spellingShingle |
Kanno, Yuki Walsh, John E. Abdillah, Muhammad R Yamaguchi, Junpei Iwasaki, Toshiki Indicators and trends of polar cold airmass |
author_facet |
Kanno, Yuki Walsh, John E. Abdillah, Muhammad R Yamaguchi, Junpei Iwasaki, Toshiki |
author_sort |
Kanno, Yuki |
title |
Indicators and trends of polar cold airmass |
title_short |
Indicators and trends of polar cold airmass |
title_full |
Indicators and trends of polar cold airmass |
title_fullStr |
Indicators and trends of polar cold airmass |
title_full_unstemmed |
Indicators and trends of polar cold airmass |
title_sort |
indicators and trends of polar cold airmass |
publisher |
IOP Publishing |
publishDate |
2019 |
url |
https://hdl.handle.net/11250/2726660 https://doi.org/10.1088/1748-9326/aaf42b |
geographic |
Arctic Pacific |
geographic_facet |
Arctic Pacific |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
Environmental Research Letters 14 2 1-11 |
op_relation |
urn:issn:1748-9326 https://hdl.handle.net/11250/2726660 https://doi.org/10.1088/1748-9326/aaf42b cristin:1800000 |
op_rights |
Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no Copyright 2019 The Author(s). |
op_doi |
https://doi.org/10.1088/1748-9326/aaf42b |
container_title |
Environmental Research Letters |
container_volume |
14 |
container_issue |
2 |
container_start_page |
025006 |
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1766329999603793920 |