DOI: 10.1007/s00382-012-1624-5
Scopus记录号: 2-s2.0-84891624417
论文题名: Equatorial Atlantic variability and its relation to mean state biases in CMIP5
作者: Richter I. ; Xie S.-P. ; Behera S.K. ; Doi T. ; Masumoto Y.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2014
卷: 42, 期: 2017-01-02 起始页码: 171
结束页码: 188
语种: 英语
英文关键词: Bjerknes feedback
; CMIP5
; Double ITCZ
; Equatorial Atlantic
; Equatorial Kelvin waves
; GCM biases
; Interannual variability
; Surface winds
英文摘要: Coupled general circulation model (GCM) simulations participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5) are analyzed with respect to their performance in the equatorial Atlantic. In terms of the mean state, 29 out of 33 models examined continue to suffer from serious biases including an annual mean zonal equatorial SST gradient whose sign is opposite to observations. Westerly surface wind biases in boreal spring play an important role in the reversed SST gradient by deepening the thermocline in the eastern equatorial Atlantic and thus reducing upwelling efficiency and SST cooling in the following months. Both magnitude and seasonal evolution of the biases are very similar to what was found previously for CMIP3 models, indicating that improvements have only been modest. The weaker than observed equatorial easterlies are also simulated by atmospheric GCMs forced with observed SST. They are related to both continental convection and the latitudinal position of the intertropical convergence zone (ITCZ). Particularly the latter has a strong influence on equatorial zonal winds in both the seasonal cycle and interannual variability. The dependence of equatorial easterlies on ITCZ latitude shows a marked asymmetry. From the equator to 15°N, the equatorial easterlies intensify approximately linearly with ITCZ latitude. When the ITCZ is south of the equator, on the other hand, the equatorial easterlies are uniformly weak. Despite serious mean state biases, several models are able to capture some aspects of the equatorial mode of interannual SST variability, including amplitude, pattern, phase locking to boreal summer, and duration of events. The latitudinal position of the boreal spring ITCZ, through its influence on equatorial surface winds, appears to play an important role in initiating warm events. © 2012 Springer-Verlag Berlin Heidelberg. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/54371
Appears in Collections: 过去全球变化的重建
There are no files associated with this item.
作者单位: Research Institute for Global Change, JAMSTEC, 3173-25 Showa-machi, Kanazawa-ku, Yokohama, Kanagawa, 236-0001, Japan; Application Laboratory, JAMSTEC, Yokohama, Japan; International Pacific Research Center, University of Hawaii at Manoa, Honolulu, HI, United States; Department of Meteorology, University of Hawaii at Manoa, Honolulu, HI, United States; Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA, United States
Recommended Citation:
Richter I.,Xie S.-P.,Behera S.K.,et al. Equatorial Atlantic variability and its relation to mean state biases in CMIP5[J]. Climate Dynamics,2014-01-01,42(2017-01-02)