DOI: 10.1175/JCLI-D-17-0715.1
Scopus记录号: 2-s2.0-85052945404
论文题名: Variability of the cold season climate in central asia. Part I: Weather types and their tropical and extratropical drivers
作者: Gerlitz L. ; Steirou E. ; Schneider C. ; Moron V. ; Vorogushyn S. ; Merz B.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2018
卷: 31, 期: 18 起始页码: 7185
结束页码: 7207
语种: 英语
英文关键词: Climate variability
; El Nino
; Interannual variability
; Planetary waves
; Regional effects
Scopus关键词: Climate change
; Tropics
; Climate variability
; EL Nino
; Interannual variability
; Planetary Waves
; Regional effects
; Moisture
英文摘要: To understand the atmospheric mechanisms resulting in a pronounced cold season climate variability in central Asia, an objective weather-type classification is conducted, utilizing a k-means-based clustering approach applied to 500-hPa geopotential height (GPH) fields. Eight weather types (WT) are identified and analyzed with regard to characteristic pressure patterns and moisture fluxes over Eurasia and specific nearsurface climate conditions over central Asia. To identify remote drivers of the central Asian climate, WT frequencies are analyzed for their relationships with tropical and extratropical teleconnection modes. The results indicate an influence of Northern Hemispheric planetary wave tracks on westerly moisture fluxes with positive anomalies of precipitation associated with the formation of a Rossby trough over central Asia. Particularly the propagation of the east Atlantic-western Russia and the Scandinavian patterns is shown to modulate regional climate conditions. Variations of ENSO are shown to affect the frequency of particular WTs because of the formation of an anticyclonic anomaly over the Indian Ocean and an increase of tropical fluxes of moisture and heat into central Asia during El Niño events. Further aWT internal influence of ENSO is distinctly defined, with enhanced moisture supply during the ENSO warm phase. The analysis of climatic trends shows that 50% of observed temperature changes can be assigned to variations of theWTcomposition, indicating that most likely changing regional circulation characteristics account for the enhanced warming rates in central Asia. Trends of precipitation sums are likewise shown to be associated with changing WT frequencies, although the WT-precipitation relationships include large uncertainties. © 2018 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110692
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Department of Hydrology, GFZ German Research Centre for Geosciences, Potsdam, Germany; Institute of Geography, Humboldt University of Berlin, Berlin, Germany; Aix-Marseille University, CNRS, IRD, INRA, Collège de France, CEREGE, Aix-en-Provence, France; International Research Institute for Climate and Society, Columbia University, Palisades, NY, United States
Recommended Citation:
Gerlitz L.,Steirou E.,Schneider C.,et al. Variability of the cold season climate in central asia. Part I: Weather types and their tropical and extratropical drivers[J]. Journal of Climate,2018-01-01,31(18)