Regional Climate Modelling over Southern Africa Mary-Jane M. Kgatuke South African Weather Service

The effect of topography CSIRO GCM TOPO MAX TEMP DARLAM TOPO

DARLAM CSIRO Atmospheric Research, Australia Configuration over Africa Africa 0º 30º 10º 20º 40º 0º 10º20º 30º 40º50º 100 x 100 grid points on a Lambert Conformal Projection (60x60 km resolution) 18 sigma layers in the vertical Boundary values supplied by CSIRO9 (R21) AGCM – crosses Semi-Lagragian advection & McGregor cumulus convection parameterization Time step of 15 minutes integrating the hydrostatic equations forward in time SIMULATES 30 DAYS IN 2 HOURS ON A LOCAL LRAM

Three 10-year regional model simulations forced by the global CSIRO-9 (R21) AGCM for the A2 SRES scenario Basis climate average over 10 years REGIONAL SCALE CLIMATE CHANGE SCENARIO MODEL SIMULATIONS OVER SUB- SAHARAH AFRICA

January January MAX TEMP ANOMALY MIN TEMP ANOMALY

January January RAINFALL ANOMALY MSLP ANOMALY

Models Models tend to be set up according to the performance of physical parameterizations chosen to represent different processes. The performance of the models will be different and therefore it is necessary to use different models for the same target area.

Models implemented in South Africa Regional climate studies –DARLAM at the University of Pretoria –RegCM2 at the South African Weather Service Short term forecasting at the South African Weather Service –ETA (operational) –MM5

RegCM2 over Southern Africa RegCM2 has been used to simulate tropical cyclone-like vortex tracks in the southern Indian Ocean Resolution:60 km Forcing fields: ECMWF Cumulus parameterization: Grell Time step :150 s

Objectives of the project with RegCM3(1) Examine the skill of RegCM3 in simulating regional climate over southern Africa. Determine the extent to which the simulations are compromised by errors in predicted SST’s and GCM output. Determine if RegCM3 is capable of simulating the variability between wet and dry periods.

Objectives of the project with RegCM3(2) Determine the skill of RegCM3 in capturing extreme rainfall events.

Thank you