气候变化领域集成服务门户(CCPortal): The northern hemisphere circumglobal teleconnection in a seasonal forecast model and its relationship to European summer forecast skill

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DOI	10.1007/s00382-018-4371-4
	The northern hemisphere circumglobal teleconnection in a seasonal forecast model and its relationship to European summer forecast skill
	Beverley J.D.; Woolnough S.J.; Baker L.H.; Johnson S.J.; Weisheimer A.
发表日期	2019
ISSN	0930-7575
起始页码	3759
结束页码	3771
卷号	52 期号:2020-05-06
英文摘要	Forecasting seasonal variations in European summer weather represents a considerable challenge. Here, we assess the performance of a seasonal forecasting model at representing a major mode of northern hemisphere summer climate variability, the circumglobal teleconnection (CGT), and the implications of errors in its representation on seasonal forecasts for the European summer (June, July, August). Using seasonal hindcasts initialised at the start of May, we find that the model skill for forecasting the interannual variability of 500 hPa geopotential height is poor, particularly over Europe and several other “centres of action” of the CGT. The model also has a weaker CGT pattern than is observed, particularly in August, when the observed CGT wavetrain is strongest. We investigate several potential causes of this poor skill. First, model variance in geopotential height in west-central Asia (an important region for the maintenance of the CGT) is lower than observed in July and August, associated with a poor representation of the link between this region and Indian monsoon precipitation. Second, analysis of the Rossby wave source shows that the source associated with monsoon heating is both too strong and displaced to the northeast in the model. This is related to errors in monsoon precipitation over the Bay of Bengal and Arabian Sea, where the model has more precipitation than is observed. Third, the model jet is systematically shifted northwards by several degrees latitude over large parts of the northern hemisphere, which may affect the propagation characteristics of Rossby waves in the model. © 2018, The Author(s).
英文关键词	Indian monsoon; Seasonal forecasting; Teleconnection
语种	英语
scopus关键词	climate variation; forecasting method; monsoon; Northern Hemisphere; Rossby wave; seasonal variation; teleconnection; Arabian Sea; Bay of Bengal; Europe; Indian Ocean
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/146443
作者单位	Department of Meteorology, University of Reading, Earley Gate, Reading, RG6 6BB, United Kingdom; Department of Meteorology, National Centre for Atmospheric Science, University of Reading, Earley Gate, Reading, RG6 6BB, United Kingdom; ECMWF, Shinfield Park, Reading, RG2 9AX, United Kingdom; Department of Physics, National Centre for Atmospheric Science (NCAS), University of Oxford, Oxford, OX1 3PU, United Kingdom
推荐引用方式 GB/T 7714	Beverley J.D.,Woolnough S.J.,Baker L.H.,et al. The northern hemisphere circumglobal teleconnection in a seasonal forecast model and its relationship to European summer forecast skill[J],2019,52(2020-05-06).
APA	Beverley J.D.,Woolnough S.J.,Baker L.H.,Johnson S.J.,&Weisheimer A..(2019).The northern hemisphere circumglobal teleconnection in a seasonal forecast model and its relationship to European summer forecast skill.Climate Dynamics,52(2020-05-06).
MLA	Beverley J.D.,et al."The northern hemisphere circumglobal teleconnection in a seasonal forecast model and its relationship to European summer forecast skill".Climate Dynamics 52.2020-05-06(2019).