气候变化领域集成服务门户(CCPortal): Quasi-resonant circulation regimes and hemispheric synchronization of extreme weather in boreal summer

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DOI	10.1073/pnas.1412797111
	Quasi-resonant circulation regimes and hemispheric synchronization of extreme weather in boreal summer
	Coumou D.; Petoukhov V.; Rahmstorf S.; Petri S.; Schellnhuber H.J.
发表日期	2014
ISSN	0027-8424
起始页码	12331
结束页码	12336
卷号	111 期号:34
英文摘要	The recent decade has seen an exceptional number of high-impact summer extremes in the Northern Hemisphere midlatitudes. Many of these events were associated with anomalous jet stream circulation patterns characterized by persistent high-amplitude quasi-stationary Rossby waves. Two mechanisms have recently been proposed that could provoke such patterns: (i) a weakening of the zonal mean jets and (ii) an amplification of quasi-stationary waves by resonance between free and forced waves in midlatitude waveguides. Based upon spectral analysis of the midtroposphere wind field, we show that the persistent jet stream patterns were, in the first place, due to an amplification of quasi-stationary waves with zonal wave numbers 6-8. However, we also detect a weakening of the zonal mean jet during these events; thus both mechanisms appear to be important. Furthermore, we demonstrate that the anomalous circulation regimes lead to persistent surface weather conditions and therefore to midlatitude synchronization of extreme heat and rainfall events on monthly timescales. The recent cluster of resonance events has resulted in a statistically significant increase in the frequency of high-amplitude quasi-stationary waves of wave numbers 7 and 8 in July and August. We show that this is a robust finding that holds for different pressure levels and reanalysis products. We argue that recent rapid warming in the Arctic and associated changes in the zonal mean zonal wind have created favorable conditions for double jet formation in the extratropics, which promotes the development of resonant flow regimes.
英文关键词	Arctic amplification; Climate change; Climate impact; Midlatitude weather; Planetary waves
语种	英语
scopus关键词	rain; altitude; article; controlled study; heat; Northern Hemisphere; priority journal; Southern Hemisphere; summer; surface property; wind
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/158917
作者单位	Coumou, D., Potsdam Institute for Climate Impact Research, 14412 Potsdam, Germany; Petoukhov, V., Potsdam Institute for Climate Impact Research, 14412 Potsdam, Germany; Rahmstorf, S., Potsdam Institute for Climate Impact Research, 14412 Potsdam, Germany; Petri, S., Potsdam Institute for Climate Impact Research, 14412 Potsdam, Germany; Schellnhuber, H.J., Potsdam Institute for Climate Impact Research, 14412 Potsdam, Germany, Santa Fe Institute, Santa Fe, NM 87501, United States
推荐引用方式 GB/T 7714	Coumou D.,Petoukhov V.,Rahmstorf S.,et al. Quasi-resonant circulation regimes and hemispheric synchronization of extreme weather in boreal summer[J],2014,111(34).
APA	Coumou D.,Petoukhov V.,Rahmstorf S.,Petri S.,&Schellnhuber H.J..(2014).Quasi-resonant circulation regimes and hemispheric synchronization of extreme weather in boreal summer.Proceedings of the National Academy of Sciences of the United States of America,111(34).
MLA	Coumou D.,et al."Quasi-resonant circulation regimes and hemispheric synchronization of extreme weather in boreal summer".Proceedings of the National Academy of Sciences of the United States of America 111.34(2014).