DOI: 10.1175/JCLI-D-17-0804.1
Scopus记录号: 2-s2.0-85050250777
论文题名: The impact of Indian Ocean mean-state biases in climate models on the representation of the East African short rains
作者: Hirons L. ; Turner A.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2018
卷: 31, 期: 16 起始页码: 6611
结束页码: 6631
语种: 英语
英文关键词: Advection
; Africa
; Climate models
; Indian Ocean
; Sea surface temperature
; Teleconnections
Scopus关键词: Advection
; Atmospheric temperature
; Feedback
; Oceanography
; Rain
; Submarine geophysics
; Surface properties
; Surface waters
; Wind stress
; Africa
; Equatorial Indian Ocean
; Indian ocean
; Interannual variability
; Latitudinal structures
; Sea surface temperature (SST)
; Sea Surface Temperature gradients
; Teleconnections
; Climate models
; advection
; air-sea interaction
; annual variation
; climate modeling
; Indian Ocean Dipole
; precipitation (climatology)
; sea surface temperature
; teleconnection
; westerly
; wind stress
; East Africa
; Indian Ocean
; Indian Ocean (Equatorial)
英文摘要: The role of the Indian Ocean dipole (IOD) in controlling interannual variability in the East African short rains, from October to December, is examined in state-of-the-art models and in detail in one particular climate model. In observations, a wet short-rainy season is associated with the positive phase of the IOD and anomalous easterly low-level flow across the equatorial Indian Ocean. A model's ability to capture the teleconnection to the positive IOD is closely related to its representation of the mean state. During the short-rains season, the observed low-level wind in the equatorial Indian Ocean is westerly. However, half of the models analyzed exhibit mean-state easterlies across the entire basin. Specifically, those models that exhibit mean-state low-level equatorial easterlies in the Indian Ocean, rather than the observed westerlies, are unable to capture the latitudinal structure of moisture advection into East Africa during a positive IOD. Furthermore, the associated anomalous easterly surface wind stress causes upwelling in the eastern Indian Ocean. This upwelling draws up cool subsurface waters, enhancing the zonal sea surface temperature gradient between west and east and strengthening the positive IOD pattern, further amplifying the easterly wind stress. This positive Bjerknes coupled feedback is stronger in easterly mean-state models, resulting in a wetter East African short-rain precipitation bias in those models. © 2018 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/111449
Appears in Collections: 气候减缓与适应
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作者单位: National Centre for Atmospheric Science, University of Reading, Reading, United Kingdom; Department of Meteorology, University of Reading, Reading, United Kingdom; National Centre for Atmospheric Science, University of Reading, Reading, United Kingdom
Recommended Citation:
Hirons L.,Turner A.. The impact of Indian Ocean mean-state biases in climate models on the representation of the East African short rains[J]. Journal of Climate,2018-01-01,31(16)