The nature of intraseasonal and interannual variability of African easterly waves (AEWs) in IPCC–CMIP3 global simulations
is investigated in comparison with 40-year NCEP and ERA40 products. AEWs are a major source of atmospheric variability over
the Sahel and particularly over West Africa. An accurate representation of AEWs dynamics is therefore an important precondition
to skilled climate predictions and seasonal forecasts for this area. We describe the synoptic features of these disturbances
and we illustrate a statistical link, at interannual timescale, between Sea Surface Temperature and AEWs activity. At intraseasonal
time scale, the models exhibit a wide variety of behaviours in reproducing the synoptic features of the disturbances, namely
AEWs amplitude and pattern. It is possible to classify the models into two groups, one localizing intense variability well
inside the continental area, and the other exhibiting a weaker variance mostly placed over West Africa. Concerning the inter-annual
variability, we point out a statistical link between SST anomalies and AEWs activity that reveals a strong influence of the
ENSO events on the variability of the disturbances over the Guinean coasts. Warm/cold ENSO events occur in conjunction with
suppressed/enhanced AEWs through upper tropospheric teleconnection bridge. Only two model running at significantly different
vertical and horizontal resolution (INM and INGV-SGX) are able to reproduce this mechanism in accordance to what observed
in the global reanalysis systems. Our result introduces non-negligible caveats with respect to the ability of most of CMIP3 models in obtaining reliable description of AEWs.