期刊名称：Science et changements planétaires / Sécheresse
印刷版ISSN：1147-7806
电子版ISSN：1777-5922
出版年度：2005
卷号：16
期号：2
页码：97-106
出版社：John Libbey Eurotext
摘要：Figures See all figures Authors Yves Richard , Yan Zhao , Pierre Camberlin Centre de recherches de climatologie (CRC), Faculté des sciences Gabriel, 6, boulevard Gabriel, 21000 Dijon, France Key words: Climatology, Climate change, Rainfall, Modelling, South Africa Page(s) : 97-106 Published in: 2005 While water demand is growing, access to water resources is at the origin of multiple issues in South Africa. Global warming may have a dramatic impact on water availability. General circulation models (GCMs) including the foreseeable changes occurring in the chemical composition of the atmosphere (greenhouse gas and aerosols) remain key tools for the study of the climate of the 21st century. In addition to the uncertainties associated with emission scenarios, the ability of GCMs to simulate climate at regional scales is variable. For the austral summer (January-March), over the period 1970-1999, the ARPEGE/OPA (Météo-France) coupled model adequately simulates sea-level pressure (SLP) over Southern Africa and the neighbouring oceans. By contrast, precipitation is overestimated, and spatial patterns are smoothened. In order to offset the weaknesses of the GCM, we developed a statistical regional downscaling method for January-March precipitation. The statistical relations between observed SLP and rainfall are strong (1970-1999). They are used to project on small-scale rainfall areas the evolution of regional SLP as simulated by the GCM for the period 2070-2099. Based on emission scenario B2, the ARPEGE/OPA model, together with our statistical downscaling model, simulates a 16% decrease of summer rainfall. The decrease is strongest over the South-Western part of the Veld plateau.
关键词：Climatology; Climate change; Rainfall; Modelling; South Africa
