Typhoon strength rising in the past four decades

Quantitative and climatological analysis on the tracks and cyclogenesis locations of all 77 typhoons that hit Taiwan in the last 40 years (1977–2016) during typhoon season (May to November) is carried out. Ten pathways of all typhoons that hit Taiwan are detected with almost 1.9 typhoons per year. 53% of typhoons hit Taiwan from the East direction, typically (78%) only from the Philippine Sea. Typhoons from the West uniquely survive the longest hours with the highest sinuous tracks, often (59%) only from the South China Sea. Typhoons striking Taiwan from the East are the most intense whereas from the West the least intense. The Fisher's Exact and Chi-square (χ2) tests also establish that the sinuous nature of the tracks of typhoons is more responsible for the longer survival of typhoons (r = 0.67) than its strength. 26% more cyclogenesis is detected during the warm phase of El Niño Southern Oscillation (ENSO) than in the cold phase, which is also gradually rising in the last 4 decades. A 35% crucial growth in the strength of typhoons that hit Taiwan is observed by 0.4–0.7 °C rise in the Sea Surface Temperature (SST) in all four responsible oceans during the last 40 years (1977–2016). The role of the El-Niño epochs is found very crucial for the major SSTA changes during the typhoon season. The climatological analysis is fully consistent with statistical findings and leads to global warming as the major cause of the rising strength of typhoons that hit Taiwan during the study period.