Projected changes of summer monsoon extremes and hydroclimatic regimes over West Africa for the twenty-first century

摘要: We use two CORDEX-Africa simulations performed with the regional model RegCM4 to characterize projected changes in extremes and hydroclimatic regimes associated West African Monsoon (WAM). was driven for period 1970–2100 by HadGEM2-ES MPI-ESM Global Climate Models (GCMs) under RCP8.5 greenhouse gas concentration pathway. accurately simulates WAM characteristics terms of seasonal mean, cycle, interannual variability extreme events rainfall. Overall, both experiments are able reproduce large-scale atmospheric circulation reference (i.e. present-day), fact show improved performance compared driving GCMs precipitation mean climatology events, although different shortcomings various models still evident. Precipitation is decrease (increase) over western (eastern) Sahel, spatial detail between corresponding GCMs. Changes patterns line those change. The project water budget Sahel region, where MPI projects an increased deficit local moisture supply (E   P). E–P change primarily driven. increases eastern and/or central attributed increase convergence due vapor boundary layer air column surface evaporation. On other hand, dry conditions strengthening divergence upper level (850–300 hPa) combined a southward migration Easterly Jet (AEJ) weakening rising motion core AEJ Tropical Jet.