Tightening of tropical ascent and high clouds key to precipitation change in a warmer climate
Abstract
The change of global-mean precipitation under global warming and interannual variability is predominantly controlled by the change of atmospheric longwave radiative cooling. Here we show that tightening of the ascending branch of the Hadley Circulation coupled with a decrease in tropical high cloud fraction is key in modulating precipitation response to surface warming. The magnitude of high cloud shrinkage is a primary contributor to the intermodel spread in the changes of tropical-mean outgoing longwave radiation (OLR) and global-mean precipitation per unit surface warming (dP/dT_s) for both interannual variability and global warming. Compared to observations, most Coupled Model Inter-comparison Project Phase 5 models underestimate the rates of interannual tropical-mean dOLR/dT_s and global-mean dP/dT_s, consistent with the muted tropical high cloud shrinkage. We find that the five models that agree with the observation-based interannual dP/dT_s all predict dP/dT_s under global warming higher than the ensemble mean dP/dT_s from the ∼20 models analysed in this study.
Additional Information
© 2017 The Author(s). This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. Received: 20 June 2016; Accepted: 27 April 2017; Published online: 07 June 2017. We acknowledge the funding support from NASA NEWS, AST, MAP, NDOA and NSF. We greatly appreciate Michael Wong in making the schematic figure. We thank Shang-min Long, Ryan Stanfield and Jung-Min Park for assistance in some parts of the auxicillary analyses. We thank Drs Brian Soden and Karen Shell for providing the radiative kernel functions. We appreciate helpful discussions with Drs Chris Bretherton, Anthony DeAngelis, Feifei Jin, Xin Qu and Shang-Ping Xie. We thank three anonymous reviewers for insightful suggestions. This work was performed at Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Author Contributions: H.S. designed the analysis and wrote the paper. H.S., J.H.J., T.J.S. and C.Z. analysed the CMIP5 model simulations and observations. Q.Y. analysed the MODIS cloud fraction data. Z.W. and L.H. analysed the joint CloudSat/CALIPSO cloud fraction retrieval. Y.-S.C. analysed the combined ERBE-CERES data. J.D.N., G.L.S. and Y.L.Y. provided suggestions for the analysis and comments on the manuscript. Everyone edited the manuscript. The authors declare no competing financial interests.Attached Files
Published - ncomms15771.pdf
Supplemental Material - ncomms15771-s1.pdf
Supplemental Material - ncomms15771-s2.pdf
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Additional details
- PMCID
- PMC5467267
- Eprint ID
- 78082
- Resolver ID
- CaltechAUTHORS:20170612-073313585
- NASA/JPL/Caltech
- NSF
- Created
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2017-06-12Created from EPrint's datestamp field
- Updated
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2022-03-25Created from EPrint's last_modified field
- Caltech groups
- Astronomy Department, Division of Geological and Planetary Sciences