The response of African easterly waves and associated precipitation to enhanced radiative forcing

African easterly waves (AEWs) are the dominant synoptic scale feature of the West African summer climate. The majority of precipitation in the Sahel results from convection organized within these synoptic disturbances. Despite their well-known association with rainfall over Africa, large uncertainties remain regarding the interaction between AEWs and convection. First, a single-model ensemble approach is applied with a regional climate model (RegCM3) to improve understanding of the relationship between AEWs and convective processes. Four convective schemes are employed within the ensemble and their interaction with AEW initiation and development is analyzed. Spectral peaks in precipitation over West Africa exist at the easterly wave timescales in each of the ensemble members, however precipitation magnitude and AEW amplitude and location of preferred propagation are found to be sensitive to the representation of convective processes. In addition, we analyze the relationship between AEW activity and precipitation during the 20th century within the suite of general circulation models (GCMs) used in the CMIP3 and CMIP5 datasets. The models are assessed based on their ability to simulate the wave disturbances and summer precipitation. Second, the influence of enhanced radiative forcing on AEWs and their associated precipitation is explored. Using both the regional climate model ensemble, and the CMIP datasets, we then attempt to quantify the impact of changes in AEW activity as a result of enhanced radiative forcing on projected precipitation over West Africa. Preliminary results indicate substantial changes to the magnitude of AEW activity within the suite of CMIP GCMs. This work aims to improve upon our understanding of the mechanisms responsible for the disparate projections of 21st century rainfall over West Africa among the current generation of GCMs.