DOI: 10.1007/s00382-013-1907-5
Scopus记录号: 2-s2.0-84884703157
论文题名: CFSv2 prediction skill of stratospheric temperature anomalies
作者: Zhang Q. ; Shin C.-S. ; van den Dool H. ; Cai M.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2013
卷: 41, 期: 2017-07-08 起始页码: 2231
结束页码: 2249
语种: 英语
英文关键词: CFSv2 model
; Seasonal prediction
; Stratosphere dynamics
; Wave-mean flow interaction
英文摘要: This study evaluates the prediction skill of stratospheric temperature anomalies by the Climate Forecast System version 2 (CFSv2) reforecasts for the 12-year period from January 1, 1999 to December 2010. The goal is to explore if the CFSv2 forecasts for the stratosphere would remain skillful beyond the inherent tropospheric predictability time scale of at most 2 weeks. The anomaly correlation between observations and forecasts for temperature field at 50 hPa (T50) in winter seasons remains above 0.3 over the polar stratosphere out to a lead time of 28 days whereas its counterpart in the troposphere at 500 hPa drops more quickly and falls below the 0.3 level after 12 days. We further show that the CFSv2 has a high prediction skill in the stratosphere both in an absolute sense and in terms of gain over persistence except in the equatorial region where the skill would mainly come from persistence of the quasi-biennial oscillation signal. We present evidence showing that the CFSv2 forecasts can capture both timing and amplitude of wave activities in the extratropical stratosphere at a lead time longer than 30 days. Based on the mass circulation theory, we conjecture that as long as the westward tilting of planetary waves in the stratosphere and their overall amplitude can be captured, the CFSv2 forecasts is still very skillful in predicting zonal mean anomalies even though it cannot predict the exact locations of planetary waves and their spatial scales. This explains why the CFSv2 has a high skill for the first EOF mode of T50, the intraseasonal variability of the annular mode while its skill degrades rapidly for higher EOF modes associated with stationary waves. This also explains why the CFSv2's skill closely follows the seasonality and its interannual variability of the meridional mass circulation and stratosphere polar vortex. In particular, the CFSv2 is capable of predicting mid-winter polar stratosphere warming events in the Northern Hemisphere and the timing of the final polar stratosphere warming in spring in both hemispheres 3-4 weeks in advance. © 2013 Springer-Verlag Berlin Heidelberg. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/54777
Appears in Collections: 过去全球变化的重建
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作者单位: Climate Prediction Center, NCEP/NWS/NOAA, College Park, MD, United States; Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL, 32306, United States; Center for Ocean-Land-Atmosphere Studies, George Mason University, Fairfax, VA, 22030, United States
Recommended Citation:
Zhang Q.,Shin C.-S.,van den Dool H.,et al. CFSv2 prediction skill of stratospheric temperature anomalies[J]. Climate Dynamics,2013-01-01,41(2017-07-08)