Reassessment of shortwave surface cloud radiative forcing in the Arctic: consideration of surface-albedo–cloud interactions
The concept of cloud radiative forcing (CRF) is commonly applied to quantify the impact of clouds on the surface radiative energy budget (REB). In the Arctic, specific radiative interactions between microphysical and macrophysical properties of clouds and the surface strongly modify the warming or c...
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Copernicus Publications
2020
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00052858 2023-05-15T13:10:26+02:00 Reassessment of shortwave surface cloud radiative forcing in the Arctic: consideration of surface-albedo–cloud interactions Stapf, Johannes Ehrlich, André Jäkel, Evelyn Lüpkes, Christof Wendisch, Manfred 2020-08 electronic https://doi.org/10.5194/acp-20-9895-2020 https://noa.gwlb.de/receive/cop_mods_00052858 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00052511/acp-20-9895-2020.pdf https://acp.copernicus.org/articles/20/9895/2020/acp-20-9895-2020.pdf eng eng Copernicus Publications Atmospheric Chemistry and Physics -- http://www.atmos-chem-phys.net/volumes_and_issues.html -- http://www.bibliothek.uni-regensburg.de/ezeit/?2069847 -- 1680-7324 https://doi.org/10.5194/acp-20-9895-2020 https://noa.gwlb.de/receive/cop_mods_00052858 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00052511/acp-20-9895-2020.pdf https://acp.copernicus.org/articles/20/9895/2020/acp-20-9895-2020.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess CC-BY article Verlagsveröffentlichung article Text doc-type:article 2020 ftnonlinearchiv https://doi.org/10.5194/acp-20-9895-2020 2022-02-08T22:35:45Z The concept of cloud radiative forcing (CRF) is commonly applied to quantify the impact of clouds on the surface radiative energy budget (REB). In the Arctic, specific radiative interactions between microphysical and macrophysical properties of clouds and the surface strongly modify the warming or cooling effect of clouds, complicating the estimate of CRF obtained from observations or models. Clouds tend to increase the broadband surface albedo over snow or sea ice surfaces compared to cloud-free conditions. However, this effect is not adequately considered in the derivation of CRF in the Arctic so far. Therefore, we have quantified the effects caused by surface-albedo–cloud interactions over highly reflective snow or sea ice surfaces on the CRF using radiative transfer simulations and below-cloud airborne observations above the heterogeneous springtime marginal sea ice zone (MIZ) during the Arctic CLoud Observations Using airborne measurements during polar Day (ACLOUD) campaign. The impact of a modified surface albedo in the presence of clouds, as compared to cloud-free conditions, and its dependence on cloud optical thickness is found to be relevant for the estimation of the shortwave CRF. A method is proposed to consider this surface albedo effect on CRF estimates by continuously retrieving the cloud-free surface albedo from observations under cloudy conditions, using an available snow and ice albedo parameterization. Using ACLOUD data reveals that the estimated average shortwave cooling by clouds almost doubles over snow- and ice-covered surfaces (−62 W m−2 instead of −32 W m−2), if surface-albedo–cloud interactions are considered. As a result, the observed total (shortwave plus longwave) CRF shifted from a warming effect to an almost neutral one. Concerning the seasonal cycle of the surface albedo, it is demonstrated that this effect enhances shortwave cooling in periods when snow dominates the surface and potentially weakens the cooling by optically thin clouds during the summertime melting season. These findings suggest that the surface-albedo–cloud interaction should be considered in global climate models and in long-term studies to obtain a realistic estimate of the shortwave CRF to quantify the role of clouds in Arctic amplification. Article in Journal/Newspaper albedo Arctic Sea ice Niedersächsisches Online-Archiv NOA Arctic Atmospheric Chemistry and Physics 20 16 9895 9914 |
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Niedersächsisches Online-Archiv NOA |
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ftnonlinearchiv |
language |
English |
topic |
article Verlagsveröffentlichung |
spellingShingle |
article Verlagsveröffentlichung Stapf, Johannes Ehrlich, André Jäkel, Evelyn Lüpkes, Christof Wendisch, Manfred Reassessment of shortwave surface cloud radiative forcing in the Arctic: consideration of surface-albedo–cloud interactions |
topic_facet |
article Verlagsveröffentlichung |
description |
The concept of cloud radiative forcing (CRF) is commonly applied to quantify the impact of clouds on the surface radiative energy budget (REB). In the Arctic, specific radiative interactions between microphysical and macrophysical properties of clouds and the surface strongly modify the warming or cooling effect of clouds, complicating the estimate of CRF obtained from observations or models. Clouds tend to increase the broadband surface albedo over snow or sea ice surfaces compared to cloud-free conditions. However, this effect is not adequately considered in the derivation of CRF in the Arctic so far. Therefore, we have quantified the effects caused by surface-albedo–cloud interactions over highly reflective snow or sea ice surfaces on the CRF using radiative transfer simulations and below-cloud airborne observations above the heterogeneous springtime marginal sea ice zone (MIZ) during the Arctic CLoud Observations Using airborne measurements during polar Day (ACLOUD) campaign. The impact of a modified surface albedo in the presence of clouds, as compared to cloud-free conditions, and its dependence on cloud optical thickness is found to be relevant for the estimation of the shortwave CRF. A method is proposed to consider this surface albedo effect on CRF estimates by continuously retrieving the cloud-free surface albedo from observations under cloudy conditions, using an available snow and ice albedo parameterization. Using ACLOUD data reveals that the estimated average shortwave cooling by clouds almost doubles over snow- and ice-covered surfaces (−62 W m−2 instead of −32 W m−2), if surface-albedo–cloud interactions are considered. As a result, the observed total (shortwave plus longwave) CRF shifted from a warming effect to an almost neutral one. Concerning the seasonal cycle of the surface albedo, it is demonstrated that this effect enhances shortwave cooling in periods when snow dominates the surface and potentially weakens the cooling by optically thin clouds during the summertime melting season. These findings suggest that the surface-albedo–cloud interaction should be considered in global climate models and in long-term studies to obtain a realistic estimate of the shortwave CRF to quantify the role of clouds in Arctic amplification. |
format |
Article in Journal/Newspaper |
author |
Stapf, Johannes Ehrlich, André Jäkel, Evelyn Lüpkes, Christof Wendisch, Manfred |
author_facet |
Stapf, Johannes Ehrlich, André Jäkel, Evelyn Lüpkes, Christof Wendisch, Manfred |
author_sort |
Stapf, Johannes |
title |
Reassessment of shortwave surface cloud radiative forcing in the Arctic: consideration of surface-albedo–cloud interactions |
title_short |
Reassessment of shortwave surface cloud radiative forcing in the Arctic: consideration of surface-albedo–cloud interactions |
title_full |
Reassessment of shortwave surface cloud radiative forcing in the Arctic: consideration of surface-albedo–cloud interactions |
title_fullStr |
Reassessment of shortwave surface cloud radiative forcing in the Arctic: consideration of surface-albedo–cloud interactions |
title_full_unstemmed |
Reassessment of shortwave surface cloud radiative forcing in the Arctic: consideration of surface-albedo–cloud interactions |
title_sort |
reassessment of shortwave surface cloud radiative forcing in the arctic: consideration of surface-albedo–cloud interactions |
publisher |
Copernicus Publications |
publishDate |
2020 |
url |
https://doi.org/10.5194/acp-20-9895-2020 https://noa.gwlb.de/receive/cop_mods_00052858 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00052511/acp-20-9895-2020.pdf https://acp.copernicus.org/articles/20/9895/2020/acp-20-9895-2020.pdf |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
albedo Arctic Sea ice |
genre_facet |
albedo Arctic Sea ice |
op_relation |
Atmospheric Chemistry and Physics -- http://www.atmos-chem-phys.net/volumes_and_issues.html -- http://www.bibliothek.uni-regensburg.de/ezeit/?2069847 -- 1680-7324 https://doi.org/10.5194/acp-20-9895-2020 https://noa.gwlb.de/receive/cop_mods_00052858 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00052511/acp-20-9895-2020.pdf https://acp.copernicus.org/articles/20/9895/2020/acp-20-9895-2020.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/acp-20-9895-2020 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
20 |
container_issue |
16 |
container_start_page |
9895 |
op_container_end_page |
9914 |
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1766229917944512512 |