McCoy, DT, Field, P orcid.org/0000-0001-8528-0088, Bodas-Salcedo, A et al. (2 more authors) (2020) A Regime-Oriented Approach to Observationally Constraining Extratropical Shortwave Cloud Feedbacks. Journal of Climate, 33 (23). pp. 9967-9983. ISSN 0894-8755
Abstract
The extratropical shortwave (SW) cloud feedback is primarily due to increases in extratropical liquid cloud extent and optical depth. Here, we examine the response of extratropical (35°–75°) marine cloud liquid water path (LWP) to a uniform 4-K increase in sea surface temperature (SST) in global climate models (GCMs) from phase 5 of the Coupled Model Intercomparison Project (CMIP5) and variants of the HadGEM3-GC3.1 GCM. Compositing is used to partition data into periods inside and out of cyclones. The response of extratropical LWP to a uniform SST increase and associated atmospheric response varies substantially among GCMs, but the sensitivity of LWP to cloud controlling factors (CCFs) is qualitatively similar. When all other predictors are held constant, increasing moisture flux drives an increase in LWP. Increasing SST, holding all other predictors fixed, leads to a decrease in LWP. The combinations of these changes lead to LWP, and by extension reflected SW, increasing with warming in both hemispheres. Observations predict an increase in reflected SW over oceans of 0.8–1.6 W m−2 per kelvin SST increase (35°–75°N) and 1.2–1.9 W m−2 per kelvin SST increase (35°–75°S). This increase in reflected SW is mainly due to increased moisture convergence into cyclones because of increasing available moisture. The efficiency at which converging moisture is converted into precipitation determines the amount of liquid cloud. Thus, cyclone precipitation processes are critical to constraining extratropical cloud feedbacks.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2020 American Meteorological Society. Reproduced in accordance with the publisher's self-archiving policy. |
Keywords: | Climate sensitivity; Cloud cover; Cloud microphysics; Cloud radiative effects; Clouds |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst for Climate & Atmos Science (ICAS) (Leeds) |
Funding Information: | Funder Grant number EU - European Union GA 641727 |
Depositing User: | Symplectic Publications |
Date Deposited: | 25 Apr 2022 12:01 |
Last Modified: | 25 Apr 2022 12:01 |
Status: | Published |
Publisher: | American Meteorological Society |
Identification Number: | 10.1175/jcli-d-19-0987.1 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:185996 |