DOI: 10.1007/s00382-016-3052-4
Scopus记录号: 2-s2.0-84960381737
论文题名: Projected changes of summer monsoon extremes and hydroclimatic regimes over West Africa for the twenty-first century
作者: Diallo I. ; Giorgi F. ; Deme A. ; Tall M. ; Mariotti L. ; Gaye A.T.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2016
卷: 47, 期: 12 起始页码: 3931
结束页码: 3954
语种: 英语
英文关键词: Climate change
; CORDEX
; Dynamical downscaling
; Hydrological cycle
; Precipitation extreme
; RegCM4
; West African summer monsoon climate
英文摘要: We use two CORDEX-Africa simulations performed with the regional model RegCM4 to characterize the projected changes in extremes and hydroclimatic regimes associated with the West African Monsoon (WAM). RegCM4 was driven for the period 1970–2100 by the HadGEM2-ES and the MPI-ESM Global Climate Models (GCMs) under the RCP8.5 greenhouse gas concentration pathway. RegCM4 accurately simulates the WAM characteristics in terms of seasonal mean, seasonal cycle, interannual variability and extreme events of rainfall. Overall, both RegCM4 experiments are able to reproduce the large-scale atmospheric circulation for the reference period (i.e. present-day), and in fact show improved performance compared to the driving GCMs in terms of precipitation mean climatology and extreme events, although different shortcomings in the various models are still evident. Precipitation is projected to decrease (increase) over western (eastern) Sahel, although with different spatial detail between RegCM4 and the corresponding driving GCMs. Changes in extreme precipitation events show patterns in line with those of the mean change. The models project different changes in water budget over the Sahel region, where the MPI projects an increased deficit in local moisture supply (E < P) whereas the rest of models project a local surplus (E > P). The E–P change is primarily precipitation driven. The precipitation increases over the eastern and/or central Sahel are attributed to the increase of moisture convergence due to increased water vapor in the boundary layer air column and surface evaporation. On the other hand, the projected dry conditions over the western Sahel are associated with the strengthening of moisture divergence in the upper level (850–300 hPa) combined to both a southward migration of the African Easterly Jet (AEJ) and a weakening of rising motion between the core of the AEJ and the Tropical Easterly Jet. © 2016, Springer-Verlag Berlin Heidelberg. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/53433
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Geography, University of California, Los Angeles (UCLA), 315 Portola Plaza, #1255 (Bunche Hall, UCLA), Los Angeles, CA, United States; Earth System Physics Section, The Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy; Laboratoire de Physique de l’Atmosphère et de l’Océan Siméon Fongang (LPAO-SF), Ecole Supérieure Polytechnique, Université Cheikh Anta Diop (ESP-UCAD), Dakar, Senegal; Université Gaston Berger de Saint Louis, Unité de Formation et de Recherche Sciences Appliquées et technologie (UFR-SAT), Ngalléle/Saint Louis, Senegal
Recommended Citation:
Diallo I.,Giorgi F.,Deme A.,et al. Projected changes of summer monsoon extremes and hydroclimatic regimes over West Africa for the twenty-first century[J]. Climate Dynamics,2016-01-01,47(12)