Influence of ENSO on Tropical Cyclone Intensity in the Fiji Region

Savin S. Chand, Kevin J. E. Walsh
2011 Journal of Climate  
This study examines the variation in tropical cyclone (TC) intensity for different phases of the El Niñ o-Southern Oscillation (ENSO) phenomenon in the Fiji, Samoa, and Tonga (FST) region. The variation in TC intensity is inferred from the accumulated cyclone energy (ACE), which is constructed from the 6-hourly Joint Typhoon Warning Center best-track data for the period 1985-2006. Overall, results suggest that ACE in the FST region is considerably influenced by the ENSO signal. A substantial
more » ... tribution to this ENSO signal in ACE comes from the region equatorward of 158S where TC numbers, lifetime, and intensity all play a significant role. However, the ACE-ENSO relationship weakens substantially poleward of 158S where large-scale environmental variables affecting TC intensity are found to be less favorable during El Niñ o years than during La Niñ a years; in the region equatorward of 158S, the reverse is true. Therefore, TCs entering this region poleward of 158S are able to sustain their intensity for a longer period of time during La Niñ a years as opposed to TCs entering the region during El Niñ o years, when they decay more rapidly.
doi:10.1175/2011jcli4178.1 fatcat:d6r52v3t7ba3dnmaannpby27e4