气候变化领域集成服务门户(CCPortal): A-Train estimates of the sensitivity of the cloud-to-rainwater ratio to cloud size, relative humidity, and aerosols

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DOI	10.5194/acp-21-2765-2021
	A-Train estimates of the sensitivity of the cloud-to-rainwater ratio to cloud size, relative humidity, and aerosols
	M. Smalley K.; D. Rapp A.
发表日期	2021
ISSN	1680-7316
起始页码	2765
结束页码	2779
卷号	21 期号:4
英文摘要	Precipitation efficiency has been found to play an important role in constraining the sensitivity of the climate through its role in controlling cloud cover, yet its controls are not fully understood. Here we use CloudSat observations to identify individual contiguous shallow cumulus cloud objects and compute the ratio of cloud water path to rainwater (WRR) path as a proxy for warm-rain efficiency. Cloud objects are then conditionally sampled by cloud-top height, relative humidity, and aerosol optical depth (AOD) to analyze changes in WRR as a function of cloud size (extent). For a fixed cloud-top height, WRR increases with extent and environmental humidity following a double power-law distribution, as a function of extent. Similarly, WRR increases, holding average relative humidity at or below 850 mb constant. There is little relationship between WRR and AOD when conditioned by cloud-top height, suggesting that, once rain drop formation begins, aerosols may not be as important for WRR as cloud size and depth. Consistent with prior studies, results show an increase in WRR with sea-surface temperature. However, for a given depth and SST, WRR is also dependent on cloud size and becomes larger as cloud size increases. Given that larger objects become more frequent with increasing SST, these results imply that increasing precipitation efficiencies with SST are due not only to deeper clouds with greater cloud water contents but also to the propensity for larger clouds which may have more protected updrafts. © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License.
语种	英语
scopus关键词	aerosol; CloudSat; cumulus; optical depth; power law distribution; rainwater; relative humidity; sea surface temperature; sensitivity analysis
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/247119
作者单位	Department of Atmospheric Sciences, Texas AandM University, College Station, TX, United States
推荐引用方式 GB/T 7714	M. Smalley K.,D. Rapp A.. A-Train estimates of the sensitivity of the cloud-to-rainwater ratio to cloud size, relative humidity, and aerosols[J],2021,21(4).
APA	M. Smalley K.,&D. Rapp A..(2021).A-Train estimates of the sensitivity of the cloud-to-rainwater ratio to cloud size, relative humidity, and aerosols.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(4).
MLA	M. Smalley K.,et al."A-Train estimates of the sensitivity of the cloud-to-rainwater ratio to cloud size, relative humidity, and aerosols".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.4(2021).