气候变化领域集成服务门户(CCPortal): Improving the Southern Ocean cloud albedo biases in a general circulation model

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DOI	10.5194/acp-20-7741-2020
	Improving the Southern Ocean cloud albedo biases in a general circulation model
	Varma V.; Morgenstern O.; Field P.; Furtado K.; Williams J.; Hyder P.
发表日期	2020
ISSN	1680-7316
起始页码	7741
结束页码	7751
卷号	20 期号:13
英文摘要	The present generation of global climate models is characterised by insufficient reflection of short-wave radiation over the Southern Ocean due to a misrepresentation of clouds. This is a significant concern as it leads to excessive heating of the ocean surface, sea surface temperature biases and subsequent problems with atmospheric dynamics. In this study, we modify cloud microphysics in a recent version of the Met Office's Unified Model and show that choosing a more realistic value for the shape parameter of atmospheric ice crystals, in better agreement with theory and observations, benefits the simulation of short-wave radiation. In the model, for calculating the growth rate of ice crystals through deposition, the default assumption is that all ice particles are spherical in shape. We modify this assumption to effectively allow for oblique shapes or aggregates of ice crystals. Along with modified ice nucleation temperatures, we achieve a reduction in the annual-mean short-wave cloud radiative effect over the Southern Ocean by up to ~ 4 W m-2 and seasonally much larger reductions compared to the control model. By slowing the growth of the ice phase, the model simulates substantially more supercooled liquid cloud. © Author(s) 2020.
语种	英语
scopus关键词	albedo; atmospheric deposition; cloud microphysics; cloud radiative forcing; general circulation model; ice crystal; shortwave radiation; Southern Ocean
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/247675
作者单位	National Institute of Water and Atmospheric Research (NIWA), Wellington, New Zealand; Met Office, Exeter, United Kingdom
推荐引用方式 GB/T 7714	Varma V.,Morgenstern O.,Field P.,et al. Improving the Southern Ocean cloud albedo biases in a general circulation model[J],2020,20(13).
APA	Varma V.,Morgenstern O.,Field P.,Furtado K.,Williams J.,&Hyder P..(2020).Improving the Southern Ocean cloud albedo biases in a general circulation model.ATMOSPHERIC CHEMISTRY AND PHYSICS,20(13).
MLA	Varma V.,et al."Improving the Southern Ocean cloud albedo biases in a general circulation model".ATMOSPHERIC CHEMISTRY AND PHYSICS 20.13(2020).