The interaction of tropical cyclones with the Saharan Air Layer: model case studies from 2004

It has been suggested that the presence of the Saharan Air Layer in the vicinity of tropical cyclones has a negative impact on tropical cyclone intensity. In the framework of the African Monsoon: Multidisciplinary Analysis (AMMA) programme we are modelling the interaction of the Saharan Air Layer with tropical cyclones using the Lokal-Modell (LM) of the Deutscher Wetterdienst with a module describing the transport of mineral dust. We present results from a period in 2004 in which Hurricanes Danielle, Frances, and Ivan developed from African Easterly Waves moving off the West African coast. We discuss the representation of the cyclogenesis events in a sequence of 3 day forecasts with the LM and describe the transport of mineral dust by the monsoon weather systems during this period.