The Influence of African Easterly Waves on Atlantic Tropical Cyclone Tracks and Landfall in Large Ensembles

African Easterly Waves (AEWs) are an important precursor for Atlantic tropical cyclone (TC) development, with 60-80% of major hurricanes observed to originate from AEWs. However, climate model simulations indicate that AEWs have no significant effect on annual Atlantic TC frequency. Furthermore, small ensembles of simulations suggest that AEWs may influence the distribution of TC genesis location and TC environmental conditions, suggesting that AEWs may have an impact on the spatial distribution and landfall of Atlantic TCs. Here, we investigated the influence of AEWs on the spatial distribution of Atlantic TC tracks and landfall using 50-member ensembles of TC-permitting regional model simulations. The simulations include multiple hurricane seasons characterized by different levels of TC activity and by different ratios of landfalling to the total number of TCs generated from AEWs. The control simulations are seasonal hindcasts in which AEWs are prescribed through the eastern lateral boundary condition using reanalysis. In the experiments, we suppressed AEWs by applying a 2-10 day filter to the eastern lateral boundary condition. We plan to analyze the response in Atlantic TC frequency, as well as the spatial distribution of TC tracks and landfall. In addition, we will evaluate how suppressing AEWs influences the environmental conditions experienced by the TCs and TC steering flow. Our planned analysis aims to uncover potential shifts in the spatial distribution of TC genesis in order to understand changes in environments that TCs will experience in the absence of AEWs, which will give us insight to the change in TC tracks and landfall. By uncovering the connections between TC precursors and the likelihood of TC landfall and impacts, this research can provide Atlantic coastal and island communities with useful information to prepare for the risk of TCs.