Role of easterly wave in the maintenance of the easterly jet

The maintenance of the unstable African easterly jet is studied using a global, three-dimensional, dry, primitive equations model. This unstable jet gives rise to African easterly waves within which about half of the tropical storms in the Atlantic Ocean originate.

While the northerly gradient of surface temperature and the intertropical convergence zone over northern Africa strenghten the African easterly jet, easterly waves weaken it. The relative importance of diabatic heating and easterly waves in maintainig the African Easterly Jet is studied using model set ups that range from simple zonally symmetric to more complex asymmetric simulations that include midlatitude baroclinic waves.