Identification of moisture sources in the Atlantic Ocean for cyclogenesis processes

We used the Lagrangian model FLEXPART to identify the moisture sources of 110 tropical cyclones with cyclogenesis within an area comprised between 15 – 45 W and 8 – 20 N. The model computes changes in the specific humidity from a 10-day period before the day of cyclogenesis of each tropical cyclone is and its contribution to the moisture budget of the region of interest. We calculated the values of the anomalies of the moisture budget to identify the main regions of moisture sources: the African coasts in the North Atlantic, the continental region over western Africa and along the South African coast. We also calculated the contribution of moisture sources from the South Atlantic to the cyclogenesis. The frequency distribution of these percentages shows two main peaks, one in ~20% and other in ~50%. The result shows that the path of tropical cyclones with ~50% of moisture contribution from the South Atlantic made landfall more often than those with ~20%.