气候变化领域集成服务门户(CCPortal): Yearly evolution of Euro-Atlantic weather regimes and of their sub-seasonal predictability

CCPortal

DOI	10.1007/s00382-021-05679-y
	Yearly evolution of Euro-Atlantic weather regimes and of their sub-seasonal predictability
	Cortesi N.; Torralba V.; Lledó L.; Manrique-Suñén A.; Gonzalez-Reviriego N.; Soret A.; Doblas-Reyes F.J.
发表日期	2021
ISSN	0930-7575
起始页码	1767
结束页码	1782
英文摘要	It is often assumed that weather regimes adequately characterize atmospheric circulation variability. However, regime classifications spanning many months and with a low number of regimes may not satisfy this assumption. The first aim of this study is to test such hypothesis for the Euro-Atlantic region. The second one is to extend the assessment of sub-seasonal forecast skill in predicting the frequencies of occurrence of the regimes beyond the winter season. Two regime classifications of four regimes each were obtained from sea level pressure anomalies clustered from October to March and from April to September respectively. Their spatial patterns were compared with those representing the annual cycle. Results highlight that the two regime classifications are able to reproduce most part of the patterns of the annual cycle, except during the transition weeks between the two periods, when patterns of the annual cycle resembling Atlantic Low regime are not also observed in any of the two classifications. Forecast skill of Atlantic Low was found to be similar to that of NAO+, the regime replacing Atlantic Low in the two classifications. Thus, although clustering yearly circulation data in two periods of 6 months each introduces a few deviations from the annual cycle of the regime patterns, it does not negatively affect sub-seasonal forecast skill. Beyond the winter season and the first ten forecast days, sub-seasonal forecasts of ECMWF are still able to achieve weekly frequency correlations of r = 0.5 for some regimes and start dates, including summer ones. ECMWF forecasts beat climatological forecasts in case of long-lasting regime events, and when measured by the fair continuous ranked probability skill score, but not when measured by the Brier skill score. Thus, more efforts have to be done yet in order to achieve minimum skill necessary to develop forecast products based on weather regimes outside winter season. © 2021, The Author(s).
英文关键词	Climate services; Euro-Atlantic; Forecasts; Predictability; Regime patterns; Sub-seasonal; Verification; Weather regimes
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/183236
作者单位	Barcelona Supercomputing Center (BSC), Carrer Jordi Girona 29, Barcelona, Spain; Institució Catalana de Recerca i Estudis Avançats, Pg. Lluís Companys 23, Barcelona, Spain
推荐引用方式 GB/T 7714	Cortesi N.,Torralba V.,Lledó L.,et al. Yearly evolution of Euro-Atlantic weather regimes and of their sub-seasonal predictability[J],2021.
APA	Cortesi N..,Torralba V..,Lledó L..,Manrique-Suñén A..,Gonzalez-Reviriego N..,...&Doblas-Reyes F.J..(2021).Yearly evolution of Euro-Atlantic weather regimes and of their sub-seasonal predictability.Climate Dynamics.
MLA	Cortesi N.,et al."Yearly evolution of Euro-Atlantic weather regimes and of their sub-seasonal predictability".Climate Dynamics (2021).