Tightening of tropical ascent and high clouds key to precipitation change in a warmer climate
| Autor: | Chengxing Zhai, Hui Su, Zhien Wang, Jonathan H. Jiang, Lei Huang, J. David Neelin, Yong-Sang Choi, Yuk L. Yung, Graeme L. Stephens, T. Janice Shen, Qing Yue |
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| Rok vydání: | 2017 |
| Předmět: |
Multidisciplinary
010504 meteorology & atmospheric sciences Radiative cooling Science Ensemble average Global warming Cloud fraction Longwave General Physics and Astronomy General Chemistry 010502 geochemistry & geophysics Atmospheric sciences complex mixtures 01 natural sciences Article General Biochemistry Genetics and Molecular Biology Outgoing longwave radiation Environmental science sense organs Precipitation Hadley cell skin and connective tissue diseases 0105 earth and related environmental sciences |
| Zdroj: | Nature Communications, Vol 8, Iss 1, Pp 1-9 (2017) Nature Communications |
| ISSN: | 2041-1723 |
| Popis: | 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/dTs) 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/dTs and global-mean dP/dTs, consistent with the muted tropical high cloud shrinkage. We find that the five models that agree with the observation-based interannual dP/dTs all predict dP/dTs under global warming higher than the ensemble mean dP/dTs from the ∼20 models analysed in this study. The sensitivity of global precipitation to warming is largely governed by changes in atmospheric longwave radiation, a function of cloud cover. Here the authors show that tightening of the tropical circulation with warming drives a decrease in high cloud cover, resulting in higher precipitation changes. |
| Databáze: | OpenAIRE |
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