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DOI	10.5194/acp-21-10179-2021
	On the contribution of fast and slow responses to precipitation changes caused by aerosol perturbations
	Zhang S.; Stier P.; Watson-Parris D.
发表日期	2021
ISSN	1680-7316
起始页码	10179
结束页码	10197
卷号	21 期号:13
英文摘要	Changes in global-mean precipitation are strongly constrained by global radiative cooling, while regional rainfall changes are less constrained because energy can be transported. Absorbing and non-absorbing aerosols have different effects on both global-mean and regional precipitation, due to the distinct effects on energetics. This study analyses the precipitation responses to large perturbations in black carbon (BC) and sulfate (SUL) by examining the changes in atmospheric energy budget terms on global and regional scales, in terms of fast (independent of changes in sea surface temperature, SST) and slow responses (mediated by changes in SST). Changes in atmospheric radiative cooling/heating are further decomposed into contributions from clouds, aerosols, and clear-clean sky (without clouds or aerosols). Both cases show a decrease in global-mean precipitation, which is dominated by fast responses in the BC case and slow responses in the SUL case. The geographical patterns are distinct too. The intertropical convergence zone (ITCZ), accompanied by tropical rainfall, shifts northward in the BC case, while it shifts southward in the SUL case. For both cases, energy transport terms from the slow response dominate the changes in tropical rainfall, which are associated with the northward (southward) shift of the Hadley cell in response to the enhanced southward (northward) cross-equatorial energy flux caused by increased BC (SUL) emission. The extra-tropical precipitation decreases in both cases. For the BC case, fast responses to increased atmospheric radiative heating contribute most to the reduced rainfall, in which absorbing aerosols directly heat the mid-troposphere, stabilise the column, and suppress precipitation. Unlike BC, non-absorbing aerosols decrease surface temperatures through slow processes, cool the whole atmospheric column, and reduce specific humidity, which leads to decreased radiative cooling from the clear-clean sky, which is consistent with the reduced rainfall. Examining the changes in large-scale circulation and local thermodynamics qualitatively explains the responses of precipitation to aerosol perturbations, whereas the energetic perspective provides a method to quantify their contributions. © 2021 Shipeng Zhang et al.
语种	英语
scopus关键词	aerosol composition; aerosol formation; black carbon; energy flux; intertropical convergence zone; perturbation; precipitation (climatology)
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/246754
作者单位	Atmospheric, Oceanic and Planetary Physics, Department of Physics, University of Oxford, Oxford, United Kingdom
推荐引用方式 GB/T 7714	Zhang S.,Stier P.,Watson-Parris D.. On the contribution of fast and slow responses to precipitation changes caused by aerosol perturbations[J],2021,21(13).
APA	Zhang S.,Stier P.,&Watson-Parris D..(2021).On the contribution of fast and slow responses to precipitation changes caused by aerosol perturbations.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(13).
MLA	Zhang S.,et al."On the contribution of fast and slow responses to precipitation changes caused by aerosol perturbations".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.13(2021).