Low clouds suppress Arctic air formation and amplify high-latitude continental winter warming
High latitude continents have warmed much more rapidly in recent decades than the rest of the globe, especially in winter, and the maintenance of warm, frost-free conditions in continental interiors in winter has been a long-standing problem of past equable climates. We use an idealized single-colum...
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ftharvardudash:oai:dash.harvard.edu:1/25198700 2023-05-15T14:26:45+02:00 Low clouds suppress Arctic air formation and amplify high-latitude continental winter warming Cronin, Timothy W Tziperman, Eli 2015 application/pdf http://nrs.harvard.edu/urn-3:HUL.InstRepos:25198700 https://doi.org/10.1073/pnas.1510937112 en_US eng Proceedings of the National Academy of Sciences 10.1073/pnas.1510937112 http://www.people.fas.harvard.edu/~timothywcronin/publications.html Proceedings of the National Academy of Sciences Cronin, Timothy W., and Eli Tziperman. 2015. “Low Clouds Suppress Arctic Air Formation and Amplify High-Latitude Continental Winter Warming.” Proc Natl Acad Sci USA 112 (37) (August 31): 11490–11495. doi:10.1073/pnas.1510937112. 0027-8424 http://nrs.harvard.edu/urn-3:HUL.InstRepos:25198700 doi:10.1073/pnas.1510937112 global warming polar amplification cloud feedbacks paleoclimate Journal Article 2015 ftharvardudash https://doi.org/10.1073/pnas.1510937112 2022-04-05T09:36:00Z High latitude continents have warmed much more rapidly in recent decades than the rest of the globe, especially in winter, and the maintenance of warm, frost-free conditions in continental interiors in winter has been a long-standing problem of past equable climates. We use an idealized single-column atmospheric model across a range of conditions to study the polar-night process of air mass transformation from high-latitude maritime air, with a prescribed initial temperature profile, to much colder high-latitude continental air. We find that a low-cloud feedback { consisting of a robust increase in the duration of optically thick liquid clouds with warming of the initial state { slows radiative cooling of the surface and amplifies continental warming. This low-cloud feedback increases the continental surface air temperature by roughly two degrees for each degree increase of the initial maritime surface air temperature, effectively suppressing Arctic air formation. The time it takes for the surface air temperature to drop below freezing increases nonlinearly to over 10 days for initial maritime surface air temperatures of 15-20C. These results, supplemented by an analysis of CMIP5 climate model runs which shows large increases in cloud water path and surface cloud longwave forcing in warmer climates, suggest that the \lapse rate feedback" in simulations of anthropogenic climate change may be related to the influence of low clouds on the stratification of the lower troposphere, and also indicate that optically thick stratus cloud decks could help to maintain frost-free winter continental interiors in equable climates. Earth and Planetary Sciences Engineering and Applied Sciences Proof Article in Journal/Newspaper Arctic Arctic Climate change Global warming polar night Harvard University: DASH - Digital Access to Scholarship at Harvard Arctic Proceedings of the National Academy of Sciences 112 37 11490 11495 |
institution |
Open Polar |
collection |
Harvard University: DASH - Digital Access to Scholarship at Harvard |
op_collection_id |
ftharvardudash |
language |
English |
topic |
global warming polar amplification cloud feedbacks paleoclimate |
spellingShingle |
global warming polar amplification cloud feedbacks paleoclimate Cronin, Timothy W Tziperman, Eli Low clouds suppress Arctic air formation and amplify high-latitude continental winter warming |
topic_facet |
global warming polar amplification cloud feedbacks paleoclimate |
description |
High latitude continents have warmed much more rapidly in recent decades than the rest of the globe, especially in winter, and the maintenance of warm, frost-free conditions in continental interiors in winter has been a long-standing problem of past equable climates. We use an idealized single-column atmospheric model across a range of conditions to study the polar-night process of air mass transformation from high-latitude maritime air, with a prescribed initial temperature profile, to much colder high-latitude continental air. We find that a low-cloud feedback { consisting of a robust increase in the duration of optically thick liquid clouds with warming of the initial state { slows radiative cooling of the surface and amplifies continental warming. This low-cloud feedback increases the continental surface air temperature by roughly two degrees for each degree increase of the initial maritime surface air temperature, effectively suppressing Arctic air formation. The time it takes for the surface air temperature to drop below freezing increases nonlinearly to over 10 days for initial maritime surface air temperatures of 15-20C. These results, supplemented by an analysis of CMIP5 climate model runs which shows large increases in cloud water path and surface cloud longwave forcing in warmer climates, suggest that the \lapse rate feedback" in simulations of anthropogenic climate change may be related to the influence of low clouds on the stratification of the lower troposphere, and also indicate that optically thick stratus cloud decks could help to maintain frost-free winter continental interiors in equable climates. Earth and Planetary Sciences Engineering and Applied Sciences Proof |
format |
Article in Journal/Newspaper |
author |
Cronin, Timothy W Tziperman, Eli |
author_facet |
Cronin, Timothy W Tziperman, Eli |
author_sort |
Cronin, Timothy W |
title |
Low clouds suppress Arctic air formation and amplify high-latitude continental winter warming |
title_short |
Low clouds suppress Arctic air formation and amplify high-latitude continental winter warming |
title_full |
Low clouds suppress Arctic air formation and amplify high-latitude continental winter warming |
title_fullStr |
Low clouds suppress Arctic air formation and amplify high-latitude continental winter warming |
title_full_unstemmed |
Low clouds suppress Arctic air formation and amplify high-latitude continental winter warming |
title_sort |
low clouds suppress arctic air formation and amplify high-latitude continental winter warming |
publisher |
Proceedings of the National Academy of Sciences |
publishDate |
2015 |
url |
http://nrs.harvard.edu/urn-3:HUL.InstRepos:25198700 https://doi.org/10.1073/pnas.1510937112 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Arctic Climate change Global warming polar night |
genre_facet |
Arctic Arctic Climate change Global warming polar night |
op_relation |
10.1073/pnas.1510937112 http://www.people.fas.harvard.edu/~timothywcronin/publications.html Proceedings of the National Academy of Sciences Cronin, Timothy W., and Eli Tziperman. 2015. “Low Clouds Suppress Arctic Air Formation and Amplify High-Latitude Continental Winter Warming.” Proc Natl Acad Sci USA 112 (37) (August 31): 11490–11495. doi:10.1073/pnas.1510937112. 0027-8424 http://nrs.harvard.edu/urn-3:HUL.InstRepos:25198700 doi:10.1073/pnas.1510937112 |
op_doi |
https://doi.org/10.1073/pnas.1510937112 |
container_title |
Proceedings of the National Academy of Sciences |
container_volume |
112 |
container_issue |
37 |
container_start_page |
11490 |
op_container_end_page |
11495 |
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1766300173418364928 |