气候变化领域集成服务门户(CCPortal): Optically thin clouds in the trades

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DOI	10.5194/acp-22-6879-2022
	Optically thin clouds in the trades
	Mieslinger, Theresa; Stevens, Bjorn; Kolling, Tobias; Brath, Manfred; Wirth, Martin; Buehler, Stefan A.
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	6879
结束页码	6898
卷号	22 期号:10 页码:20
英文摘要	We develop a new method to describe the total cloud cover including optically thin clouds in trade wind cumulus cloud fields. Climate models and large eddy simulations commonly underestimate the cloud cover, while estimates from observations largely disagree on the cloud cover in the trades. Currently, trade wind clouds significantly contribute to the uncertainty in climate sensitivity estimates derived from model perturbation studies. To simulate clouds well, especially how they change in a future climate, we have to know how cloudy it is. In this study we develop a method to quantify the cloud cover from a cloud-free perspective. Using well-known radiative transfer relations we retrieve the cloud-free contribution in high-resolution satellite observations of trade cumulus cloud fields during EUREC(4)A. Knowing the cloud-free part, we can investigate the remaining cloud-related contributions consisting of areas detected by common cloud-masking algorithms and undetected areas related to optically thin clouds. We find that the cloud-mask cloud cover underestimates the total cloud cover by 33 %. Aircraft lidar measurements support our findings by showing a high abundance of optically thin clouds during EUREC(4)A. Mixing the undetected optically thin clouds into the cloud-free signal can cause an underestimation of the cloud radiative effect of up to -7.5 %. We further discuss possible artificial correlations in aerosol-cloud cover interaction studies that might arise from undetected optically thin low clouds. Our analysis suggests that the known underestimation of trade wind cloud cover and simultaneous overestimation of cloud brightness in models are even higher than assumed so far.
学科领域	Environmental Sciences; Meteorology & Atmospheric Sciences
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000802158200001
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/273047
作者单位	University of Hamburg; Max Planck Society; Helmholtz Association; German Aerospace Centre (DLR)
推荐引用方式 GB/T 7714	Mieslinger, Theresa,Stevens, Bjorn,Kolling, Tobias,et al. Optically thin clouds in the trades[J],2022,22(10):20.
APA	Mieslinger, Theresa,Stevens, Bjorn,Kolling, Tobias,Brath, Manfred,Wirth, Martin,&Buehler, Stefan A..(2022).Optically thin clouds in the trades.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(10),20.
MLA	Mieslinger, Theresa,et al."Optically thin clouds in the trades".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.10(2022):20.