DOI: 10.1175/JCLI-D-14-00291.1
Scopus记录号: 2-s2.0-84919725373
论文题名: The representation of atmospheric blocking and the associated low-frequency variability in two seasonal prediction systems
作者: Athanasiadis P.J. ; Bellucci A. ; Hermanson L. ; Scaife A.A. ; Maclachlan C. ; Arribas A. ; Materia S. ; Borrelli A. ; Gualdi S.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2014
卷: 27, 期: 24 起始页码: 9082
结束页码: 9100
语种: 英语
Scopus关键词: Atmospheric pressure
; Climatology
; Earth atmosphere
; Blocking
; General circulation model
; Intraseasonal variability
; Seasonal forecasting
; Teleconnections
; Forecasting
; boundary condition
; climate modeling
; ensemble forecasting
; error correction
; extratropical environment
; general circulation model
; North Atlantic Oscillation
; prediction
; seasonal variation
; teleconnection
; weather forecasting
; Atlantic Ocean
; Atlantic Ocean (North)
英文摘要: Primarily as a response to boundary forcings, certain components of the atmospheric intraseasonal variability are potentially predictable. Particularly referring to the extratropics, the current generation of seasonal forecasting systems is making advancements in predicting these components by realistically initializing many components of the climate system, using higher resolution and utilizing large ensemble sizes. The operational seasonal prediction system of the Met Office (UKMO) and the corresponding system of the Centro Euro-Mediterraneo sui Cambiamenti Climatici (CMCC) are analyzed in terms of their representation of different aspects of extratropical low-frequency variability. The UKMO system achieves unprecedented high scores in predicting the winter mean phase of the North Atlantic Oscillation (NAO; correlation 0.62) and the Pacific-North American pattern (PNA; correlation 0.82). The CMCC system, despite its smaller ensemble size and coarser resolution, also exhibits significant skill (0.42 for NAO, 0.51 for PNA). Low-frequency variability is underrepresented in both models, particularly in the eastern North Atlantic. Consequently, their intrinsic variability patterns (sectoral EOFs) are somewhat different from the observed patterns. Regarding the representation of wintertime Northern Hemisphere blocking, after bias correction both systems exhibit a realistic climatology of blocking frequency. In this assessment, instantaneous blocking and large-scale persistent blocking events are identified using daily geopotential height fields at 500 hPa. The blocking signature on the circulation and the dependence of blocking frequency on the NAO are also quite realistic for both systems. Finally, the Met Office system exhibits significant skill in predicting the winter mean frequency of blocking that relates to the NAO. © 2014 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/51206
Appears in Collections: 气候变化事实与影响
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作者单位: CMCC, Bologna, Italy; Met Office Hadley Centre, Exeter, United Kingdom; INGV-CMCC, Bologna, Italy
Recommended Citation:
Athanasiadis P.J.,Bellucci A.,Hermanson L.,et al. The representation of atmospheric blocking and the associated low-frequency variability in two seasonal prediction systems[J]. Journal of Climate,2014-01-01,27(24)