Bodas-Salcedo, A, Mulcahy, JP, Andrews, T et al. (4 more authors) (2019) Strong dependence of atmospheric feedbacks on mixed‐phase microphysics and aerosol‐cloud interactions in HadGEM3. Journal of Advances in Modeling Earth Systems, 11 (6). pp. 1735-1758. ISSN 1942-2466
Abstract
We analyze the atmospheric processes that explain the large changes in radiative feedbacks between the two latest climate configurations of the Hadley Centre Global Environmental model. We use a large set of atmosphere‐only climate‐change simulations (amip and amip‐p4K) to separate the contributions to the differences in feedback parameter from all the atmospheric model developments between the two latest model configurations. We show that the differences are mostly driven by changes in the shortwave cloud radiative feedback in the midlatitudes, mainly over the Southern Ocean. Two new schemes explain most of the differences: the introduction of a new aerosol scheme; and the development of a new mixed‐phase cloud scheme. Both schemes reduce the strength of the pre‐existing shortwave negative cloud feedback in the midlatitudes. The new aerosol scheme dampens a strong aerosol‐cloud interaction, and it also suppresses a negative clear‐sky shortwave feedback. The mixed‐phase scheme increases the amount of cloud liquid water path (LWP) in the present‐day and reduces the increase in LWP with warming. Both changes contribute to reducing the negative radiative feedback of the increase of LWP in the warmer climate. It also enhances a strong, pre‐existing, positive cloud fraction feedback. We assess the realism of the changes by comparing present‐day simulations against observations, and discuss avenues that could help constrain the relevant processes.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | ©2019 Crown copyright. This article is published with the permission of the Controller of HMSO and the Queen's Printer for Scotland. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made. |
Keywords: | cloud feedbacks; HadGEM3 |
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) |
Depositing User: | Symplectic Publications |
Date Deposited: | 16 May 2019 11:06 |
Last Modified: | 17 Sep 2019 09:12 |
Status: | Published |
Publisher: | American Geophysical Union |
Identification Number: | 10.1029/2019MS001688 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:146123 |