Definition differences and internal variability affect the simulated Arctic sea ice melt season
Satellite observations show that the Arctic sea ice melt season is getting longer. This lengthening has important implications for the Arctic Ocean's radiation budget, marine ecology and accessibility. Here we assess how passive microwave satellite observations of the melt season can be used fo...
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Online Access: | https://doi.org/10.5194/tc-13-1-2019 https://www.the-cryosphere.net/13/1/2019/tc-13-1-2019.pdf https://doaj.org/article/0b5677dd0f354b5c817362cc528149f9 |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:0b5677dd0f354b5c817362cc528149f9 2023-05-15T14:41:27+02:00 Definition differences and internal variability affect the simulated Arctic sea ice melt season A. Smith A. Jahn 2019-01-01 https://doi.org/10.5194/tc-13-1-2019 https://www.the-cryosphere.net/13/1/2019/tc-13-1-2019.pdf https://doaj.org/article/0b5677dd0f354b5c817362cc528149f9 en eng Copernicus Publications doi:10.5194/tc-13-1-2019 1994-0416 1994-0424 https://www.the-cryosphere.net/13/1/2019/tc-13-1-2019.pdf https://doaj.org/article/0b5677dd0f354b5c817362cc528149f9 undefined The Cryosphere, Vol 13, Pp 1-20 (2019) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2019 fttriple https://doi.org/10.5194/tc-13-1-2019 2023-01-22T19:23:49Z Satellite observations show that the Arctic sea ice melt season is getting longer. This lengthening has important implications for the Arctic Ocean's radiation budget, marine ecology and accessibility. Here we assess how passive microwave satellite observations of the melt season can be used for climate model evaluation. By using the Community Earth System Model Large Ensemble (CESM LE), we evaluate the effect of multiple possible definitions of melt onset, freeze onset and melt season length on comparisons with passive microwave satellite data, while taking into account the impacts of internal variability. We find that within the CESM LE, melt onset shows a higher sensitivity to definition choices than freeze onset, while freeze onset is more greatly impacted by internal variability. The CESM LE accurately simulates that the trend in freeze onset largely drives the observed pan-Arctic trend in melt season length. Under RCP8.5 forcing, the CESM LE projects that freeze onset dates will continue to shift later, leading to a pan-Arctic average melt season length of 7–9 months by the end of the 21st century. However, none of the available model definitions produce trends in the pan-Arctic melt season length as large as seen in passive microwave observations. This suggests a model bias, which might be a factor in the generally underestimated response of sea ice loss to global warming in the CESM LE. Overall, our results show that the choice of model melt season definition is highly dependent on the question posed, and none of the definitions exactly match the physics underlying the passive microwave observations. Article in Journal/Newspaper Arctic Global warming Sea ice The Cryosphere Unknown Arctic The Cryosphere 13 1 1 20 |
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geo envir A. Smith A. Jahn Definition differences and internal variability affect the simulated Arctic sea ice melt season |
topic_facet |
geo envir |
description |
Satellite observations show that the Arctic sea ice melt season is getting longer. This lengthening has important implications for the Arctic Ocean's radiation budget, marine ecology and accessibility. Here we assess how passive microwave satellite observations of the melt season can be used for climate model evaluation. By using the Community Earth System Model Large Ensemble (CESM LE), we evaluate the effect of multiple possible definitions of melt onset, freeze onset and melt season length on comparisons with passive microwave satellite data, while taking into account the impacts of internal variability. We find that within the CESM LE, melt onset shows a higher sensitivity to definition choices than freeze onset, while freeze onset is more greatly impacted by internal variability. The CESM LE accurately simulates that the trend in freeze onset largely drives the observed pan-Arctic trend in melt season length. Under RCP8.5 forcing, the CESM LE projects that freeze onset dates will continue to shift later, leading to a pan-Arctic average melt season length of 7–9 months by the end of the 21st century. However, none of the available model definitions produce trends in the pan-Arctic melt season length as large as seen in passive microwave observations. This suggests a model bias, which might be a factor in the generally underestimated response of sea ice loss to global warming in the CESM LE. Overall, our results show that the choice of model melt season definition is highly dependent on the question posed, and none of the definitions exactly match the physics underlying the passive microwave observations. |
format |
Article in Journal/Newspaper |
author |
A. Smith A. Jahn |
author_facet |
A. Smith A. Jahn |
author_sort |
A. Smith |
title |
Definition differences and internal variability affect the simulated Arctic sea ice melt season |
title_short |
Definition differences and internal variability affect the simulated Arctic sea ice melt season |
title_full |
Definition differences and internal variability affect the simulated Arctic sea ice melt season |
title_fullStr |
Definition differences and internal variability affect the simulated Arctic sea ice melt season |
title_full_unstemmed |
Definition differences and internal variability affect the simulated Arctic sea ice melt season |
title_sort |
definition differences and internal variability affect the simulated arctic sea ice melt season |
publisher |
Copernicus Publications |
publishDate |
2019 |
url |
https://doi.org/10.5194/tc-13-1-2019 https://www.the-cryosphere.net/13/1/2019/tc-13-1-2019.pdf https://doaj.org/article/0b5677dd0f354b5c817362cc528149f9 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Global warming Sea ice The Cryosphere |
genre_facet |
Arctic Global warming Sea ice The Cryosphere |
op_source |
The Cryosphere, Vol 13, Pp 1-20 (2019) |
op_relation |
doi:10.5194/tc-13-1-2019 1994-0416 1994-0424 https://www.the-cryosphere.net/13/1/2019/tc-13-1-2019.pdf https://doaj.org/article/0b5677dd0f354b5c817362cc528149f9 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-13-1-2019 |
container_title |
The Cryosphere |
container_volume |
13 |
container_issue |
1 |
container_start_page |
1 |
op_container_end_page |
20 |
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1766313212762914816 |