气候变化领域集成服务门户(CCPortal): The extratropical linear step response to tropical precipitation anomalies and its use in constraining projected circulation changes under climate warming

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DOI	10.1175/JCLI-D-20-0060.1
	The extratropical linear step response to tropical precipitation anomalies and its use in constraining projected circulation changes under climate warming
	Deb P.; Matthews A.J.; Joshi M.M.; Senior N.
发表日期	2020
ISSN	0894-8755
起始页码	7217
结束页码	7231
卷号	33 期号:16
英文摘要	Rossby wave trains triggered by tropical convection strongly affect the atmospheric circulation in the extratropics. Using daily gridded observational and reanalysis data, we demonstrate that a technique based on linear response theory effectively captures the linear response in 250-hPa geopotential height anomalies in the Northern Hemisphere using examples of steplike changes in precipitation over selected tropical areas during boreal winter. Application of this method to six models from phase 5 of the Coupled Model Intercomparison Project (CMIP5), using the same tropical forcing, reveals a large intermodel spread in the linear response associated with intermodel differences in Rossby waveguide structure. The technique is then applied to a projected tropicswide precipitation change in the HadGEM2-ES model during 2025-45 December-February, a period corresponding to a 28C rise in the mean global temperature under the RCP8.5 scenario. The response is found to depend on whether the mean state underlying the technique is calculated using observations, the present-day simulation, or the future projection; indeed, the bias in extratropical response to tropical precipitation because of errors in the basic state is much larger than the projected change in extratropical circulation itself. We therefore propose the linear step response method as a semiempirical method of making near-term future projections of the extratropical circulation, which should assist in quantifying uncertainty in such projections. © 2020 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).
英文关键词	Mechanical waves; Step response; Waveguides; Atmospheric circulation; Coupled Model Intercomparison Project; Extratropical circulation; Geopotential height anomalies; Linear-response theory; Precipitation change; Semi-empirical methods; Tropical precipitation; Tropics; atmospheric circulation; atmospheric convection; climate change; CMIP; future prospect; precipitation assessment; prediction; Rossby wave; teleconnection; temperature anomaly; uncertainty analysis; Pacific Ocean; Pacific Ocean (North)
语种	英语
来源期刊	Journal of Climate
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/171179
作者单位	Centre for Oceans, Rivers, Atmosphere and Land Science, Indian Institute of Technology Kharagpur, Kharagpur, India; Climatic Research Unit, School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom; Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, School of Mathematics, University of East Anglia, Norwich, United Kingdom
推荐引用方式 GB/T 7714	Deb P.,Matthews A.J.,Joshi M.M.,et al. The extratropical linear step response to tropical precipitation anomalies and its use in constraining projected circulation changes under climate warming[J],2020,33(16).
APA	Deb P.,Matthews A.J.,Joshi M.M.,&Senior N..(2020).The extratropical linear step response to tropical precipitation anomalies and its use in constraining projected circulation changes under climate warming.Journal of Climate,33(16).
MLA	Deb P.,et al."The extratropical linear step response to tropical precipitation anomalies and its use in constraining projected circulation changes under climate warming".Journal of Climate 33.16(2020).