气候变化领域集成服务门户(CCPortal): Alleviation of an Arctic Sea Ice Bias in a Coupled Model Through Modifications in the Subgrid-Scale Orographic Parameterization

CCPortal

DOI	10.1029/2020MS002111
	Alleviation of an Arctic Sea Ice Bias in a Coupled Model Through Modifications in the Subgrid-Scale Orographic Parameterization
	Gastineau G.; Lott F.; Mignot J.; Hourdin F.
发表日期	2020
ISSN	19422466
卷号	12 期号:9
英文摘要	In climate models, the subgrid-scale orography (SSO) parameterization imposes a blocked flow drag at low levels that is opposed to the local flow. In IPSL-CM6A-LR, an SSO lift force is also applied perpendicular to the local flow to account for the effect of locally blocked air in narrow valleys. Using IPSL-CM6A-LR sensitivity experiments, it is found that the tuning of both effects strongly impacts the atmospheric circulation. Increasing the blocking and reducing the lift lead to an equatorward shift of the Northern Hemisphere subtropical jet and a reduction of the midlatitude eddy-driven jet speed. It also improves the simulated synoptic variability, with a reduced storm-track intensity and increased blocking frequency over Greenland and Scandinavia. Additionally, it cools the polar lower troposphere in boreal winter. Transformed Eulerian Mean diagnostics also show that the low-level eddy-driven subsidence over the polar region is reduced consistent with the simulated cooling. The changes are amplified in coupled experiments when compared to atmosphere-only experiments, as the low-troposphere polar cooling is further amplified by the temperature and albedo feedbacks resulting from the Arctic sea ice growth. In IPSL-CM6A-LR, this corrects the warm winter bias and the lack of sea ice that were present over the Arctic before adjusting the SSO parameters. Our results, therefore, suggest that the adjustment of SSO parameterization alleviates the Arctic sea ice bias in this case. However, the atmospheric changes induced by the parametrized SSO also impact the ocean, with an equatorward shift of the Northern Hemisphere oceanic gyres and a weaker Atlantic meridional overturning circulation. ©2020. The Authors.
英文关键词	air-sea interaction; Arctic Ocean; atmospheric dynamics; climate models; orography
语种	英语
scopus关键词	Climate models; Parameterization; Troposphere; Atlantic meridional overturning circulations; Atmospheric changes; Atmospheric circulation; Equatorward shift; Lower troposphere; Northern Hemispheres; Synoptic variability; Transformed Eulerian means; Sea ice; atmosphere-ocean coupling; atmospheric circulation; climate modeling; cooling; meridional circulation; midlatitude environment; Northern Hemisphere; parameterization; polar region; sea ice; storm track; subtropical region; troposphere; Arctic; Arctic Ocean; Greenland; Scandinavia
来源期刊	Journal of Advances in Modeling Earth Systems
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/156639
作者单位	UMR LOCEAN, Sorbonne Université/IRD/MNHN/CNRS, IPSL, Paris, France; UMR LMD, ENS/Sorbonne Université/CNRS/Ecole Polytechnique, IPSL, Paris, France
推荐引用方式 GB/T 7714	Gastineau G.,Lott F.,Mignot J.,et al. Alleviation of an Arctic Sea Ice Bias in a Coupled Model Through Modifications in the Subgrid-Scale Orographic Parameterization[J],2020,12(9).
APA	Gastineau G.,Lott F.,Mignot J.,&Hourdin F..(2020).Alleviation of an Arctic Sea Ice Bias in a Coupled Model Through Modifications in the Subgrid-Scale Orographic Parameterization.Journal of Advances in Modeling Earth Systems,12(9).
MLA	Gastineau G.,et al."Alleviation of an Arctic Sea Ice Bias in a Coupled Model Through Modifications in the Subgrid-Scale Orographic Parameterization".Journal of Advances in Modeling Earth Systems 12.9(2020).