The onset of the West African monsoon simulated in a high-resolution atmospheric general circulation model with reanalyzed soil moisture fields

The simulation of the onset of the West African monsoon (WAM), associated with the northward shift of the Intertropical Convergence Zone (ITCZ) occurring in May, June, and July, is a challenging task for atmospheric general circulation models (AGCMs), because of complex water and energy balance through the land-atmosphere interaction as well as atmospheric processes. We provide evidence that a combination of state-of-the-art global fields of reanalyzed soil moisture anomalies and a sufficiently high-resolution (~50 km) AGCM produces a successful simulation of the northward shift of the ITCZ and the following onset of the WAM in July.