Reducing the uncertainty in subtropical cloud feedback

TitleReducing the uncertainty in subtropical cloud feedback
Publication TypeJournal Article
Year of Publication2016
AuthorsMyers T.A, Norris J.R
JournalGeophysical Research Letters
Volume43
Pagination2144-2148
Date Published2016/03
Type of ArticleArticle
ISBN Number0094-8276
Accession NumberWOS:000373109800044
KeywordsClouds; feedbacks; meteorology; model; radiation budget; sea-surface temperature; stratocumulus
Abstract

Large uncertainty remains on how subtropical clouds will respond to anthropogenic climate change and therefore whether they will act as a positive feedback that amplifies global warming or negative feedback that dampens global warming by altering Earth's energy budget. Here we reduce this uncertainty using an observationally constrained formulation of the response of subtropical clouds to greenhouse forcing. The observed interannual sensitivity of cloud solar reflection to varying meteorological conditions suggests that increasing sea surface temperature and atmospheric stability in the future climate will have largely canceling effects on subtropical cloudiness, overall leading to a weak positive shortwave cloud feedback (0.40.9Wm(-2)K(-1)). The uncertainty of this observationally based approximation of the cloud feedback is narrower than the intermodel spread of the feedback produced by climate models. Subtropical cloud changes will therefore complement positive cloud feedbacks identified by previous work, suggesting that future global cloud changes will amplify global warming.

DOI10.1002/2015gl067416
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