Downscaling Atmosphere-Ocean Global Climate Model Precipitation Simulations over Africa Using Bias-Corrected Lateral and Lower Boundary Conditions

摘要: A prequel study showed that dynamic downscaling using a regional climate model (RCM) over Africa improved the Goddard Institute for Space Studies Atmosphere-Ocean Global Climate Model (GISS AOGCM: ModelE) simulation of June–September rainfall patterns Africa. The current applies bias corrections to lateral and lower boundary data from AOGCM driving RCM, based on comparison 30-year actual climate. analysis examines horizontal pattern total accumulated precipitation, time versus latitude evolution zonal mean West (WA) precipitation (showing monsoon onset timing), altitude cross-section winds WA African Easterly Jet Tropical Jet). shows correcting excessively warm Atlantic sea-surface temperatures (SSTs) improves key features, whereas applying atmospheric variables RCM at boundaries does not improve simulations. We suggest projections should benefit by nesting an has demonstrated skill in simulating climate, driven with bias-corrected SST.