DOI: 10.1007/s00382-013-2027-y
Scopus记录号: 2-s2.0-84901985406
论文题名: The bi-decadal rainfall cycle, Southern Annular Mode and tropical cyclones over the Limpopo River Basin, southern Africa
作者: Malherbe J. ; Landman W.A. ; Engelbrecht F.A.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2014
卷: 42, 期: 2017-11-12 起始页码: 3121
结束页码: 3138
语种: 英语
英文摘要: The association between bi-decadal rainfall variability over southern Africa and the rainfall contributed by tropical cyclonic systems from the Southwest Indian Ocean (SWIO) provides a potential means towards understanding decadal-scale variability over parts of the region. A multi-decadal period is considered, focusing on the anomalous tropospheric patterns that induced a particularly wet 8-year long sub-period over the Limpopo River Basin. The wet sub-period was also characterized by a larger contribution to rainfall by tropical cyclones and depressions. The findings suggest that a broadening of the Hadley circulation underpinned by an anomalous anticyclonic pattern to the east of southern Africa altered tropospheric steering flow, relative vorticity and moisture contents spatially during the sub-period of 8 years. These circulation modulations induced enhanced potential for tropical systems from the SWIO to cause precipitation over the Limpopo River Basin. The same patterns are also conducive to increasing rainfall over the larger subcontinent, therefore explaining the positive association in the bi-decadal rainfall cycle and rainfall contributed by tropical cyclonic systems from the SWIO. An overview of regional circulation anomlies during alternating near-decadal wet and dry epochs is given. The regional circulation anomalies are also explained in hemispheric context, specifically in relation to the Southern Annular Mode, towards understanding variation over other parts of the Southern Hemisphere at this time scale. © 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/54347
Appears in Collections: 过去全球变化的重建
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作者单位: Agricultural Research Council, Institute for Soil, Climate and Water, Pretoria, South Africa; Department of Geography, Geoinformatics and Meteorology, University of Pretoria, Pretoria, South Africa; CSIR Natural Resources and the Environment: Climate Studies, Modelling and Environmental Health, Pretoria, South Africa; School of Geography, Archeology and Environmental Studies, University of the Witwatersrand, Johannesburg, South Africa
Recommended Citation:
Malherbe J.,Landman W.A.,Engelbrecht F.A.. The bi-decadal rainfall cycle, Southern Annular Mode and tropical cyclones over the Limpopo River Basin, southern Africa[J]. Climate Dynamics,2014-01-01,42(2017-11-12)