| DOI: | 10.1007/s00382-014-2325-z
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| Scopus记录号: | 2-s2.0-84925500783
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| 论文题名: | Drought regimes in Southern Africa and how well GCMs simulate them |
| 作者: | Ujeneza E.L.; Abiodun B.J.
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| 刊名: | Climate Dynamics
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| ISSN: | 9307575
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| 出版年: | 2015
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| 卷: | 44, 期:2017-05-06 | | 起始页码: | 1595
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| 结束页码: | 1609
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| 语种: | 英语
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| 英文关键词: | Climate indices
; Droughts
; Global climate models
; Southern Africa
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| 英文摘要: | This paper presents the spatial and temporal structures of drought regimes in Southern Africa and evaluates the capability of ten global climate models (GCMs) in simulating the regimes. The study uses a multi-scaled standardized index (called standardized precipitation evapo-transpiration index, SPEI) in characterizing droughts over Southern Africa at 3- and 12-month scales. The spatial patterns of the drought regimes are identified using the rotated principal component analysis (PCA) on the SPEI, while the temporal characteristics of the drought regimes are studied using wavelet analysis. The relationship between each drought regime and global SSTs (and climate indices) is quantified using correlation analysis and wavelet coherence analysis. The study also quantifies the capability of the GCMs in simulating the drought regimes. The PCA results show four main drought regimes that jointly explain about 50 % SPEI variance over South Africa. The drought regimes (hereafter PF1, PF2, PF3 and PF4) centre over the south-western part of Southern Africa (i.e. South Africa, Botswana and Namibia common border), Zimbabwe, Tanzania, and Angola, respectively. PF1, PF2 and PF4 are strongly correlated with SST over the South Atlantic, Tropical Pacific and Indian Oceans, while PF3 is strongly correlated with the SST over the Tropical Pacific, Atlantic and Indian Oceans. The drought regimes (except PF4) have significant coherence with some atmospheric teleconnection, but the strength, duration, and phase of the coherence vary with time. All the GCMs simulate the drought regimes better at a 3-month scale than at a 12-month scale. At a 3-month scale, 70 % of the GCMs simulate all the drought regimes with a high correlation coefficient (r > 0.6), but at a 12-month scale only 60 % of the models simulate at least three of the drought regimes with a high correlation coefficient (r > 0.6). The results of this study have applications in using GCMs to study the underlying atmospheric dynamics that control droughts and to understand the impacts of global warming on droughts. © 2014, Springer-Verlag Berlin Heidelberg. |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/54197
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| Appears in Collections: | 过去全球变化的重建
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作者单位: | Climate Systems Analysis Group, Department of Environmental and Geographical Science, University of Cape Town, Cape Town, South Africa
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| Recommended Citation: | |
Ujeneza E.L.,Abiodun B.J.. Drought regimes in Southern Africa and how well GCMs simulate them[J]. Climate Dynamics,2015-01-01,44(2017-05-06)
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