RECONSTRUCTING A LONG-TERM RECORD OF TROPICAL CYCLONES IN THE NORTH ATLANTIC FROM FLOOD DEPOSITS

Existing historical records of tropical cyclones in the North Atlantic are inadequate to improve the skill of numerical models forecasting hurricane occurrence. Discerning relevant climate variables that drive tropical cyclone development requires a lengthy high-resolution time series, particularly when attempting to tune models for long-term predictions related to global warming. A new methodology for resolving long-term hurricane occurrence in the North Atlantic is presented. Flood deposits related to heavy rainfalls from passing tropical cyclones are examined in Antigua, Eastern Caribbean, which lies in an optimal geographic location to capture many passing storms. Cyclones, and their associated rainfall, that transit within 75 km of Antigua provide a highly correlated proxy for cyclone occurrence in the entire North Atlantic basin. Sediment grain size characteristics and oxidation bands observed in cores strongly correlate to documented tropical cyclones that were proximal to Antigua over the past century. Rainfall-related flood deposits preserved in coastal lakes and marshes may provide a high-resolution storm record and serve to compliment the more traditional approach of using overwash deposits for reconstructing pre-historic storm history.