Potential faster Arctic sea ice retreat triggered by snowflakes' greenhouse effect
Recent Arctic sea ice retreat has been quicker than in most general circulation model (GCM) simulations. Internal variability may have amplified the observed retreat in recent years, but reliable attribution and projection requires accurate representation of relevant physics. Most current GCMs do no...
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fttriple:oai:gotriple.eu:oai:doaj.org/article:3e67f613ce954ab0b6683a95e95b3acb 2023-05-15T14:50:25+02:00 Potential faster Arctic sea ice retreat triggered by snowflakes' greenhouse effect J.-L. F. Li M. Richardson W.-L. Lee E. Fetzer G. Stephens J. Jiang Y. Hong Y.-H. Wang J.-Y. Yu Y. Liu 2019-03-01 https://doi.org/10.5194/tc-13-969-2019 https://www.the-cryosphere.net/13/969/2019/tc-13-969-2019.pdf https://doaj.org/article/3e67f613ce954ab0b6683a95e95b3acb en eng Copernicus Publications doi:10.5194/tc-13-969-2019 1994-0416 1994-0424 https://www.the-cryosphere.net/13/969/2019/tc-13-969-2019.pdf https://doaj.org/article/3e67f613ce954ab0b6683a95e95b3acb undefined The Cryosphere, Vol 13, Pp 969-980 (2019) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2019 fttriple https://doi.org/10.5194/tc-13-969-2019 2023-01-22T17:53:16Z Recent Arctic sea ice retreat has been quicker than in most general circulation model (GCM) simulations. Internal variability may have amplified the observed retreat in recent years, but reliable attribution and projection requires accurate representation of relevant physics. Most current GCMs do not fully represent falling ice radiative effects (FIREs), and here we show that the small set of Coupled Model Intercomparison Project Phase 5 (CMIP5) models that include FIREs tend to show faster observed retreat. We investigate this using controlled simulations with the CESM1-CAM5 model. Under 1pctCO2 simulations, including FIREs results in the first occurrence of an “ice-free” Arctic (monthly mean extent <1×106 km2) at 550 ppm CO2, compared with 680 ppm otherwise. Over 60–90∘ N oceans, snowflakes reduce downward surface shortwave radiation and increase downward surface longwave radiation, improving agreement with the satellite-based CERES EBAF-Surface dataset. We propose that snowflakes' equivalent greenhouse effect reduces the mean sea ice thickness, resulting in a thinner pack whose retreat is more easily triggered by global warming. This is supported by the CESM1-CAM5 surface fluxes and a reduced initial thickness in perennial sea ice regions by approximately 0.3 m when FIREs are included. This explanation does not apply across the CMIP5 ensemble in which inter-model variation in the simulation of other processes likely dominates. Regardless, we show that FIRE can substantially change Arctic sea ice projections and propose that better including falling ice radiative effects in models is a high priority. Article in Journal/Newspaper Arctic Global warming Sea ice The Cryosphere Unknown Arctic The Cryosphere 13 3 969 980 |
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geo envir J.-L. F. Li M. Richardson W.-L. Lee E. Fetzer G. Stephens J. Jiang Y. Hong Y.-H. Wang J.-Y. Yu Y. Liu Potential faster Arctic sea ice retreat triggered by snowflakes' greenhouse effect |
topic_facet |
geo envir |
description |
Recent Arctic sea ice retreat has been quicker than in most general circulation model (GCM) simulations. Internal variability may have amplified the observed retreat in recent years, but reliable attribution and projection requires accurate representation of relevant physics. Most current GCMs do not fully represent falling ice radiative effects (FIREs), and here we show that the small set of Coupled Model Intercomparison Project Phase 5 (CMIP5) models that include FIREs tend to show faster observed retreat. We investigate this using controlled simulations with the CESM1-CAM5 model. Under 1pctCO2 simulations, including FIREs results in the first occurrence of an “ice-free” Arctic (monthly mean extent <1×106 km2) at 550 ppm CO2, compared with 680 ppm otherwise. Over 60–90∘ N oceans, snowflakes reduce downward surface shortwave radiation and increase downward surface longwave radiation, improving agreement with the satellite-based CERES EBAF-Surface dataset. We propose that snowflakes' equivalent greenhouse effect reduces the mean sea ice thickness, resulting in a thinner pack whose retreat is more easily triggered by global warming. This is supported by the CESM1-CAM5 surface fluxes and a reduced initial thickness in perennial sea ice regions by approximately 0.3 m when FIREs are included. This explanation does not apply across the CMIP5 ensemble in which inter-model variation in the simulation of other processes likely dominates. Regardless, we show that FIRE can substantially change Arctic sea ice projections and propose that better including falling ice radiative effects in models is a high priority. |
format |
Article in Journal/Newspaper |
author |
J.-L. F. Li M. Richardson W.-L. Lee E. Fetzer G. Stephens J. Jiang Y. Hong Y.-H. Wang J.-Y. Yu Y. Liu |
author_facet |
J.-L. F. Li M. Richardson W.-L. Lee E. Fetzer G. Stephens J. Jiang Y. Hong Y.-H. Wang J.-Y. Yu Y. Liu |
author_sort |
J.-L. F. Li |
title |
Potential faster Arctic sea ice retreat triggered by snowflakes' greenhouse effect |
title_short |
Potential faster Arctic sea ice retreat triggered by snowflakes' greenhouse effect |
title_full |
Potential faster Arctic sea ice retreat triggered by snowflakes' greenhouse effect |
title_fullStr |
Potential faster Arctic sea ice retreat triggered by snowflakes' greenhouse effect |
title_full_unstemmed |
Potential faster Arctic sea ice retreat triggered by snowflakes' greenhouse effect |
title_sort |
potential faster arctic sea ice retreat triggered by snowflakes' greenhouse effect |
publisher |
Copernicus Publications |
publishDate |
2019 |
url |
https://doi.org/10.5194/tc-13-969-2019 https://www.the-cryosphere.net/13/969/2019/tc-13-969-2019.pdf https://doaj.org/article/3e67f613ce954ab0b6683a95e95b3acb |
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 969-980 (2019) |
op_relation |
doi:10.5194/tc-13-969-2019 1994-0416 1994-0424 https://www.the-cryosphere.net/13/969/2019/tc-13-969-2019.pdf https://doaj.org/article/3e67f613ce954ab0b6683a95e95b3acb |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-13-969-2019 |
container_title |
The Cryosphere |
container_volume |
13 |
container_issue |
3 |
container_start_page |
969 |
op_container_end_page |
980 |
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