Progress in regional downscaling of west African precipitation

H. Paeth (1) , N. M. J. Hall (2) , M. Á. Gaertner (3) , M. Dominguez Alonso (3) , S. Moumouni (4) , J. Polcher (5) , P. Ruti (6) , A. H. Fink (7) , M. Gosset (8) , T. Lebel (9) , A.T. Gaye (10) , D.P. Rowell (11) , W. Moufouma-Okia (11) , D. Jacob (12) , B. Rockel (13) , F. Giorgi (14) , M. Rummukainen (15)

1 Geographical Institute
2 OLVAC - Océan du Large et Variabilité Climatique
3 ICAM - Instituto de Ciencias Ambientales [Toledo]
4 UAC
5 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)
6 ENEA - Ente per le Nuove tecnologie, l'Energia e l'Ambiente
7 IGM - Institute for Geophysics and Meteorology [Köln]
8 LTHE - Laboratoire d'étude des transferts en hydrologie et environnement
9 HMCI
10 LPAO-SF - Laboratoire de Physique de l'Atmosphère et de l'Océan Siméon Fongang
11 MOHC - Met Office Hadley Centre
12 MPI-M - Max Planck Institute for Meteorology
13 GKSS
14 ICTP - Abdus Salam International Centre for Theoretical Physics [Trieste]
15 SMHI - Swedish Meteorological and Hydrological Institute

We review the recent progress in dynamical and statistical downscaling approaches for west African precipitation and perform a regional climate model (RCM) intercomparison using the novel multi-model RCM data set from the Ensembles-based Predictions of Climate Changes and Their Impacts (ENSEMBLES) and African Monsoon Multidisciplinary Analyses (AMMA) projects. Present RCMs have distinct systematic errors in terms of west African precipitation varying in amplitude and pattern across models. This is also reflected in a relatively large spread in projected future precipitation trends. Altogether, the ENSEMBLES RCMs indicate a prevailing drying tendency in sub-Saharan Africa. Statistical post-processing of simulated precipitation is a promising tool to reduce systematic model errors before application in impact studies.

Mots clés: dynamical downscaling; statistical downscaling; model intercomparison; West Africa; climate change

Domaines: Géomorphologie

H. Paeth, N. M. J. Hall, M. Á. Gaertner, M. Dominguez Alonso, S. Moumouni, et al.. Progress in regional downscaling of west African precipitation. Atmospheric Science Letters, 2011, 12 (1), pp.75-82. ⟨10.1002/asl.306⟩. ⟨insu-00648904⟩