气候变化领域集成服务门户(CCPortal): Seasonally variant low cloud adjustment over cool oceans

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DOI	10.1007/s00382-018-4478-7
	Seasonally variant low cloud adjustment over cool oceans
	Kamae Y.; Chadwick R.; Ackerley D.; Ringer M.; Ogura T.
发表日期	2019
ISSN	0930-7575
起始页码	5801
结束页码	5817
卷号	52 期号:2020-09-10
英文摘要	The Earth’s solar reflectance is reduced through rapid climate adjustments to increasing CO2, via a decrease in total cloud cover over ocean. Perturbations to marine boundary-layer clouds are essentially important for the global radiative balance at the top of the atmosphere. However, the physical robustness of low cloud adjustments to increasing CO2 has not been assessed systematically. Here we show that low cloud adjustment is distinct from that in total cloud and is seasonally variant. Among multiple climate models, marine boundary-layer clouds over the subtropics and extratropics (especially over the Northern Hemisphere) are consistently increased in the rapid adjustment, while middle and high clouds are greatly reduced. The increase in low cloud cover is only found during summer, associated with a summertime enhancement of lower tropospheric stability. We further examine mechanisms behind the rapid adjustments of low cloud and inversion strength of the boundary layer, using land surface temperature prescribing experiments in an atmospheric general circulation model (AGCM). Summertime increases in low cloud and enhanced inversion strength over the ocean simulated in this AGCM are attributed to (1) CO2-induced land warming; and (2) reduced radiative cooling in the lower troposphere due to increased CO2. The seasonality in the cloud adjustment implies an importance of seasonal variations in background cloud and atmospheric circulation related to the Hadley and monsoon circulations for radiative forcing, feedback and climate sensitivity. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.
英文关键词	Cloud adjustment; Instantaneous radiative forcing; Inversion strength; Low cloud
语种	英语
scopus关键词	atmospheric general circulation model; boundary layer; climate modeling; cloud cover; cloud radiative forcing; Northern Hemisphere; solar radiation; summer; top of atmosphere; troposphere
来源期刊	Climate Dynamics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/146336
作者单位	Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8572, Japan; Met Office Hadley Centre, Exeter, Devon, United Kingdom; Met Office, Exeter, Devon, United Kingdom; National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan
推荐引用方式 GB/T 7714	Kamae Y.,Chadwick R.,Ackerley D.,et al. Seasonally variant low cloud adjustment over cool oceans[J],2019,52(2020-09-10).
APA	Kamae Y.,Chadwick R.,Ackerley D.,Ringer M.,&Ogura T..(2019).Seasonally variant low cloud adjustment over cool oceans.Climate Dynamics,52(2020-09-10).
MLA	Kamae Y.,et al."Seasonally variant low cloud adjustment over cool oceans".Climate Dynamics 52.2020-09-10(2019).