气候变化领域集成服务门户(CCPortal): Roles of air–sea coupling and horizontal resolution in the climate model simulation of Indian monsoon low pressure systems

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DOI	10.1007/s00382-020-05526-6
	Roles of air–sea coupling and horizontal resolution in the climate model simulation of Indian monsoon low pressure systems
	Levine R.C.; Klingaman N.P.; Peatman S.C.; Martin G.M.
发表日期	2021
ISSN	0930-7575
卷号	56 期号:2021-03-04
英文摘要	The roles of air–sea coupling and horizontal resolution in the representation of Indian monsoon low pressure systems (LPS) in Met Office Unified Model (MetUM) global climate simulations are investigated. To avoid the generally large sea surface temperature (SST) biases in standard coupled atmosphere–ocean global climate models (GCMs), the analysis is performed on experiments from an atmosphere model coupled to a mixed-layer ocean model (MetUM-GOML2), which allows coupling to be applied regionally as well as globally, while constraining the ocean mean state in coupled regions. Compared to the standard AMIP-style MetUM atmosphere-only simulations, the MetUM-GOML2 simulations produce more monsoon LPS, which is attributed to effects of relatively small remaining (Indian Ocean) SST biases that somewhat strengthen the atmospheric monsoon base state. However, the MetUM-GOML2 simulations, all starting from the same atmospheric and oceanic base state, allow for an idealised approach to evaluate the relative effects of coupling and resolution. When the effects of SST biases are excluded, global coupling has a neutral impact on the number of LPS formed, while the associated rainfall is somewhat reduced due to a local negative air–sea feedback reducing the strength of atmospheric convection and weakening individual LPS. The MetUM-GOML2 simulations show particular sensitivity to localised coupling in the Indian and Pacific Oceans, which appears to enhance the effect of monsoon LPS. Although, in contrast to the global coupling comparison, the comparison of regionally coupled simulations is affected by both differences in interannual SST variability and SST biases, and it is likely that this causes at least part of the positive effects from Indian and Pacific Ocean coupling. More importantly, however, is that the effects of air–sea coupling are substantially smaller than the positive effects of the increase in horizontal resolution from N96 (approx. 200 km) to N216 (approx. 90 km). The resolution effect is also larger than that seen in older MetUM configurations. © 2020, Crown.
英文关键词	Air–sea coupling; Global Climate Model; Horizontal resolution; Indian Monsoon; Low Pressure Systems
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/183402
作者单位	Met Office Hadley Centre, Exeter, United Kingdom; National Centre for Atmospheric Science-Climate, Department of Meteorology, University of Reading, Reading, United Kingdom
推荐引用方式 GB/T 7714	Levine R.C.,Klingaman N.P.,Peatman S.C.,等. Roles of air–sea coupling and horizontal resolution in the climate model simulation of Indian monsoon low pressure systems[J],2021,56(2021-03-04).
APA	Levine R.C.,Klingaman N.P.,Peatman S.C.,&Martin G.M..(2021).Roles of air–sea coupling and horizontal resolution in the climate model simulation of Indian monsoon low pressure systems.Climate Dynamics,56(2021-03-04).
MLA	Levine R.C.,et al."Roles of air–sea coupling and horizontal resolution in the climate model simulation of Indian monsoon low pressure systems".Climate Dynamics 56.2021-03-04(2021).