DOI: 10.1007/s00382-013-2036-x
Scopus记录号: 2-s2.0-84891701613
论文题名: Are atmospheric biases responsible for the tropical Atlantic SST biases in the CNRM-CM5 coupled model?
作者: Voldoire A. ; Claudon M. ; Caniaux G. ; Giordani H. ; Roehrig R.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2014
卷: 43, 期: 11 起始页码: 2963
结束页码: 2984
语种: 英语
英文关键词: Climate
; CMIP5
; GCM
; Ocean–atmosphere coupling
; Tropical Atlantic
英文摘要: In this study, the CNRM-CM5 model is shown to simulate too warm SSTs in the tropical Atlantic as most state-of-the-art CMIP5 models. The warm bias develops within 1 or 2 months in decadal experiments initialised in January using an observationally derived state. To better quantify the role of the atmospheric biases in initiating this warm SST bias, several sensitivity experiments have been performed. In a first set of experiments, the surface solar net heat flux sent to the ocean model is academically corrected over the southeastern tropical Atlantic Ocean. This correction locally reduces the warm SST bias by more than 50 % with some remote impacts over equatorial regions. In contrast, the solar heat flux correction has locally little impact on the spring cooling. A second set of experiments quantifies the role of surface winds, using a nudging technique. When applied in a narrow equatorial region, the wind correction mainly improves the SST annual cycle amplitude along the Equator. It promotes not only the spring cooling along the Equator in preconditioning the mixed-layer depth but also in the southeastern Atlantic along the African coast. These local and remote effects are attributed to the more realistic representation of the oceanic equatorial circulation, driven by corrected winds. These results are consistent with those reported by Wahl et al. (Clim Dyn 36:891–906, 2011) in a very similar study with the Kiel Climate Model. The solar and wind biases have comparable effects in their study, although the importance of off-equatorial winds is less clear in our study. Diagnosing the wind energy flux provides a physical understanding of the equatorial region. When combining the corrections of both the equatorial wind and the southeastern solar heat flux, no obvious feedback between them is evidenced. The present study also emphasizes the need to consider two time-scales, the annual mean and the seasonal cycle, as well as two regions, the equatorial and the southeastern Atlantic regions, to comprehensively address the Atlantic SST bias. As pointed out in Richter (Clim Dyn, doi:10.1007/s00382-012-1624-5, 2013), the need to improve the atmospheric component of the CNRM-CM model is emphasized, even though strong positive coupling feedbacks are highlighted. © 2014, Springer-Verlag Berlin Heidelberg.
资助项目: NOAA, National Oceanic and Atmospheric Administration
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/54461
Appears in Collections: 过去全球变化的重建
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作者单位: CNRM-GAME (Météo-France/CNRS), Toulouse, France
Recommended Citation:
Voldoire A.,Claudon M.,Caniaux G.,et al. Are atmospheric biases responsible for the tropical Atlantic SST biases in the CNRM-CM5 coupled model?[J]. Climate Dynamics,2014-01-01,43(11)