Predictors of Tropical Cyclone Numbers and Extreme Hurricane Intensities over the North Atlantic Using Generalized Additive and Linear Models

Abstract

Fluctuations of the annual number of tropical cyclones over the North Atlantic and of the energy dissipated by the most intense hurricane of a season are related to a variety of predictors [global temperature, SST and detrended SST, North Atlantic Oscillation (NAO), Southern Oscillation index (SOI)] using generalized additive and linear models. This study demonstrates that SST and SOI are predictors of interest. The SST is found to influence positively the annual number of tropical cyclones and the intensity of the most intense hurricanes. The use of specific additive models reveals nonlinearity in the responses to SOI that has to be taken into account using changepoint models. The long-term trend in SST is found to influence the annual number of tropical cyclones but does not add information for the prediction of the most intense hurricane intensity.