Divergence of tropical cyclone hazard based on wind-weighted track distributions in the Coral Sea, over 50 years

Abstract

Tropical cyclones (TCs) with genesis in the Coral Sea present significant hazards to coastal regions in their surroundings. In addition, the erratic nature of TC tracks is not well understood in this region. Therefore, this study grouped Coral Sea TC tracks over the last fifty years based on K-means clustering of the maximum wind-weighted centroids. This was done in order to extract valuable new cyclone power, track curvature and location related information from their historical track records and to predict their behaviour in the light of a changing climate. TC track variance and curvature (sinuosity) were assessed. Three well-defined clusters of TC tracks were identified, and the results showed differing predominant directions of TC movement by cluster. Track sinuosity was shown to increase from east to west. Only one cluster showed a statistically significant trend (decreasing) in TC frequency. The TC power dissipation index (PDI) was used to reveal that two of the clusters have diverging trends for PDI post-2004. Based on the location of cyclone maximum intensity, only one cluster showed a statistically significant trend (towards the equator). All these findings demonstrated a clear variance in between-cluster hazard and show that TC trends discovered for the southwest Pacific are not manifest or consistent across all clusters.