气候变化领域集成服务门户(CCPortal): Longwave radiative effect of the cloud twilight zone

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DOI	10.1038/s41561-020-0636-8
	Longwave radiative effect of the cloud twilight zone
	Eytan E.; Koren I.; Altaratz O.; Kostinski A.B.; Ronen A.
发表日期	2020
ISSN	17520894
起始页码	669
结束页码	673
卷号	13 期号:10
英文摘要	Clouds play a key role in Earth’s radiation budget, covering more than 50% of the planet. However, the binary delineation of cloudy and clear sky is not clearly defined due to the presence of a transitionary zone, known as the cloud twilight zone, consisting of liquid droplets and humidified to dry aerosols. The twilight zone is an inherent component of cloud fields, yet its influence on longwave-infrared radiation remains unknown. Here we analyse spectral data from global satellite observations of shallow cloud fields over the ocean to estimate a lower bound on the twilight zone’s effect on longwave radiation. We find that the average longwave radiative effect of the twilight zone is ~0.75 W m–2, which is equivalent to the radiative forcing from increasing atmospheric CO2 by 75 ppm. We also find that the twilight zone in the longwave occupies over 60% of the apparent clear sky within the analysed low-level cloud fields. As low-level clouds are relatively warm, the overall longwave radiative contribution from the twilight zone is likely to be higher. We suggest that the twilight zone needs to be accounted for to accurately quantify cloud radiative effects and close the global energy budget. © 2020, The Author(s), under exclusive licence to Springer Nature Limited.
英文关键词	aerosol; atmosphere-ocean coupling; clear sky; cloud radiative forcing; longwave radiation; radiation budget; twilight
语种	英语
来源期刊	Nature Geoscience
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/206770
作者单位	Department of Earth and Planetary Science, The Weizmann Institute of Science, Rehovot, Israel; Physics Department, Michigan Technological University, Houghton, MI, United States; Department of Environmental Physics, Israel Institute for Biological Research, Nes-Ziona, Israel
推荐引用方式 GB/T 7714	Eytan E.,Koren I.,Altaratz O.,et al. Longwave radiative effect of the cloud twilight zone[J],2020,13(10).
APA	Eytan E.,Koren I.,Altaratz O.,Kostinski A.B.,&Ronen A..(2020).Longwave radiative effect of the cloud twilight zone.Nature Geoscience,13(10).
MLA	Eytan E.,et al."Longwave radiative effect of the cloud twilight zone".Nature Geoscience 13.10(2020).