[A-AS03] Advances in Tropical Cyclone Research: Past, Present, and Future

[AAS03-10] Change of Tropial Cyclone Characteristics under the Changing Climate

*Fumiya Matsushima¹, Kazuhisa Tsuboki¹, Sachie Kanada¹ (1. Institute for Space-Earth Environmental Research, Nagoya University)

Keywords:typhoons, global warming

Since typhoons cause great damage to Southeast Asia and north western Pacific regions, it is an important problem how the typhoons change with global warming. Previous studies have shown that the number and ratio of strong typhoons are increasing. However, there are no simulations that have been performed for many typhoons with high resolution, and the future changes in typhoon intensity have not been thoroughly examined. Therefore, the purpose of this study is to clarify the changes in typhoon intensity and internal structure of typhoons with global warming by examining about 60 typhoons in each climate experiment of "current climate, near-future climate, and future climate" with about 2 km horizontal resolution. Latitudes of typhoons lifetime maximum intensity are 20.38 ° , 21.61 ° and 21.95 ° N for the present climate , the near future climate and the future climate, respectively. In the future climate, the maximum intensity latitude was about 1.5 ° north of the present climate. In order to show how strong typhoons change between climate experiments, we investigated the warm core structure and wind field for the strongest 30% typhoons in each climate. From composite analyses at the maximum intensity normalized by the radius of maximum wind speed at an altitude of 2 km, the maximum potential temperature anomaly was larger in the future climate than in the present climate, and the warm core was stronger. In addition, we found that the upward vertical velocity is stronger in the future climate than the present climate. This means that secondary circulation of typhoon is stronger in the future climate. A new finding in this study is the future change of typhoon intensity shown by detailed physics-based simulations. The average minimum central pressure showed no trend with global warming. This is attributed to increases in both strong and weak typhoons in the future climate. On the other hand, focusing on typhoons with the 30% of the highest maximum intensity as strong typhoons, the average minimum central pressure in the future climate was significantly smaller than that of the present climate.