DOI: 10.1175/JCLI-D-13-00374.1
Scopus记录号: 2-s2.0-84898041354
论文题名: An objectively determined blocking index and its Northern Hemisphere climatology
作者: Small D. ; Atallah E. ; Gyakum J.R.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2014
卷: 27, 期: 8 起始页码: 2948
结束页码: 2970
语种: 英语
Scopus关键词: Climatology
; Anticyclonic circulation
; Blocking index
; Eastern pacific
; Intra-seasonal
; Intraseasonal variability
; Northern Hemispheres
; Potential vorticity
; Spatial scale
; Climate models
; anticyclone
; atmospheric blocking
; climatology
; Northern Hemisphere
; potential vorticity
; seasonal variation
; Pacific Ocean
英文摘要: A modified blocking index is defined based on vertically integrated potential vorticity. The application of this index identifies blocking activity over the Northern Hemisphere during all seasons. The index is developed by systematically identifying the magnitude and spatial scale that best characterizes persistent anticyclonic circulation anomalies in different seasons. By applying a systematic approach to the detection of blocking, the interannual, seasonal, and intraseasonal patterns of blocking frequency across the Northern Hemisphere are able to be characterized. The results are consistent with previous studies in finding that blocking is more frequent in the cold season months than in the warm season, although the results suggest that blocking occurs much more frequently in the summer and fall than many studies have previously reported. By examining blocking frequency monthly, interesting patterns of intraseasonal variability are found, especially over the central Pacific in August and the eastern Pacific in September and October, where blocking is nearly as frequent as in the winter. Possible explanations for this intraseasonal variability are discussed. © 2014 American Meteorological Society. 资助项目: NSERC, Natural Sciences and Engineering Research Council of Canada
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/51470
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Atmospheric and Oceanic Sciences, McGill University, Montreal, QC, Canada
Recommended Citation:
Small D.,Atallah E.,Gyakum J.R.. An objectively determined blocking index and its Northern Hemisphere climatology[J]. Journal of Climate,2014-01-01,27(8)