Evaluation of liquid cloud albedo susceptibility in E3SM using coupled eastern North Atlantic surface and satellite retrievals
The impact of aerosol number concentration on cloud albedo is a persistent source of spread in global climate predictions due to multi-scale, interactive atmospheric processes that remain difficult to quantify. We use 5 years of geostationary satellite and surface retrievals at the US Department of...
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ftdoajarticles:oai:doaj.org/article:f4010ff8451a4316a9f3ff35978f9281 2023-11-12T04:22:15+01:00 Evaluation of liquid cloud albedo susceptibility in E3SM using coupled eastern North Atlantic surface and satellite retrievals A. C. Varble P.-L. Ma M. W. Christensen J. Mülmenstädt S. Tang J. Fast 2023-10-01T00:00:00Z https://doi.org/10.5194/acp-23-13523-2023 https://doaj.org/article/f4010ff8451a4316a9f3ff35978f9281 EN eng Copernicus Publications https://acp.copernicus.org/articles/23/13523/2023/acp-23-13523-2023.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-23-13523-2023 1680-7316 1680-7324 https://doaj.org/article/f4010ff8451a4316a9f3ff35978f9281 Atmospheric Chemistry and Physics, Vol 23, Pp 13523-13553 (2023) Physics QC1-999 Chemistry QD1-999 article 2023 ftdoajarticles https://doi.org/10.5194/acp-23-13523-2023 2023-10-29T00:37:44Z The impact of aerosol number concentration on cloud albedo is a persistent source of spread in global climate predictions due to multi-scale, interactive atmospheric processes that remain difficult to quantify. We use 5 years of geostationary satellite and surface retrievals at the US Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) eastern North Atlantic (ENA) site in the Azores to evaluate the representation of liquid cloud albedo susceptibility for overcast cloud scenes in the DOE Energy Exascale Earth System Model version 1 (E3SMv1) and provide possible reasons for model–observation discrepancies. The overall distribution of surface 0.2 % CCN concentration values is reasonably simulated, but simulated liquid water path (LWP) is lower than observed and layer mean droplet concentration ( N d ) comparisons are highly variable depending on the N d retrieval technique. E3SMv1's cloud albedo is greater than observed for given LWP and N d values due to a lower cloud effective radius than observed. However, the simulated albedo response to N d is suppressed due to a correlation between the solar zenith angle (SZA) and N d created by the seasonal cycle that is not observed. Controlling for this effect by examining the cloud optical depth (COD) shows that E3SMv1's COD response to CCN concentration is greater than observed. For surface-based retrievals, this is only true after controlling for cloud adiabaticity because E3SMv1's adiabaticities are much lower than observed. Assuming a constant adiabaticity in surface retrievals as done in top-of-atmosphere (TOA) retrievals narrows the retrieved ln N d distribution, which increases the cloud albedo sensitivity to ln N d to match the TOA sensitivity. The greater sensitivity of COD to CCN is caused by a greater Twomey effect in which the sensitivity of N d to CCN is greater than observed for TOA-retrieved N d , and once model–observation cloud adiabaticity differences are removed, this is also true for surface-retrieved N d . The LWP response to N d in ... Article in Journal/Newspaper North Atlantic Directory of Open Access Journals: DOAJ Articles Atmospheric Chemistry and Physics 23 20 13523 13553 |
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topic |
Physics QC1-999 Chemistry QD1-999 |
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Physics QC1-999 Chemistry QD1-999 A. C. Varble P.-L. Ma M. W. Christensen J. Mülmenstädt S. Tang J. Fast Evaluation of liquid cloud albedo susceptibility in E3SM using coupled eastern North Atlantic surface and satellite retrievals |
topic_facet |
Physics QC1-999 Chemistry QD1-999 |
description |
The impact of aerosol number concentration on cloud albedo is a persistent source of spread in global climate predictions due to multi-scale, interactive atmospheric processes that remain difficult to quantify. We use 5 years of geostationary satellite and surface retrievals at the US Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) eastern North Atlantic (ENA) site in the Azores to evaluate the representation of liquid cloud albedo susceptibility for overcast cloud scenes in the DOE Energy Exascale Earth System Model version 1 (E3SMv1) and provide possible reasons for model–observation discrepancies. The overall distribution of surface 0.2 % CCN concentration values is reasonably simulated, but simulated liquid water path (LWP) is lower than observed and layer mean droplet concentration ( N d ) comparisons are highly variable depending on the N d retrieval technique. E3SMv1's cloud albedo is greater than observed for given LWP and N d values due to a lower cloud effective radius than observed. However, the simulated albedo response to N d is suppressed due to a correlation between the solar zenith angle (SZA) and N d created by the seasonal cycle that is not observed. Controlling for this effect by examining the cloud optical depth (COD) shows that E3SMv1's COD response to CCN concentration is greater than observed. For surface-based retrievals, this is only true after controlling for cloud adiabaticity because E3SMv1's adiabaticities are much lower than observed. Assuming a constant adiabaticity in surface retrievals as done in top-of-atmosphere (TOA) retrievals narrows the retrieved ln N d distribution, which increases the cloud albedo sensitivity to ln N d to match the TOA sensitivity. The greater sensitivity of COD to CCN is caused by a greater Twomey effect in which the sensitivity of N d to CCN is greater than observed for TOA-retrieved N d , and once model–observation cloud adiabaticity differences are removed, this is also true for surface-retrieved N d . The LWP response to N d in ... |
format |
Article in Journal/Newspaper |
author |
A. C. Varble P.-L. Ma M. W. Christensen J. Mülmenstädt S. Tang J. Fast |
author_facet |
A. C. Varble P.-L. Ma M. W. Christensen J. Mülmenstädt S. Tang J. Fast |
author_sort |
A. C. Varble |
title |
Evaluation of liquid cloud albedo susceptibility in E3SM using coupled eastern North Atlantic surface and satellite retrievals |
title_short |
Evaluation of liquid cloud albedo susceptibility in E3SM using coupled eastern North Atlantic surface and satellite retrievals |
title_full |
Evaluation of liquid cloud albedo susceptibility in E3SM using coupled eastern North Atlantic surface and satellite retrievals |
title_fullStr |
Evaluation of liquid cloud albedo susceptibility in E3SM using coupled eastern North Atlantic surface and satellite retrievals |
title_full_unstemmed |
Evaluation of liquid cloud albedo susceptibility in E3SM using coupled eastern North Atlantic surface and satellite retrievals |
title_sort |
evaluation of liquid cloud albedo susceptibility in e3sm using coupled eastern north atlantic surface and satellite retrievals |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/acp-23-13523-2023 https://doaj.org/article/f4010ff8451a4316a9f3ff35978f9281 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Atmospheric Chemistry and Physics, Vol 23, Pp 13523-13553 (2023) |
op_relation |
https://acp.copernicus.org/articles/23/13523/2023/acp-23-13523-2023.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-23-13523-2023 1680-7316 1680-7324 https://doaj.org/article/f4010ff8451a4316a9f3ff35978f9281 |
op_doi |
https://doi.org/10.5194/acp-23-13523-2023 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
23 |
container_issue |
20 |
container_start_page |
13523 |
op_container_end_page |
13553 |
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1782337335264804864 |