Intensification of Landfalling Typhoons over Coastal Shallow Water Shelf

In August of 2017, Typhoon Hato and Hurricane Harvey struck the casino city of Macau in South Asia and Texas of the US, respectively. Both cases are high impact events that drew international attention. The former became the worst typhoon to hit Macau in 55 years, whereas the latter was the costliest hurricane in US history. Interestingly, what they have in common is the fact that they experienced rapid intensification over the coastal shallow water during the landfall period. Such unexpected fast intensity jump is in part, if not all, responsible for the serious consequences. People started to ask what causes these cyclones to rapidly intensify during the landfall period. Indeed, the intensification of the typhoon is one of the most challenge problems in typhoon research, not to mention the rapid intensity change. Recently, from the ocean prospective, pioneer work from Pun et al. (2019) and Potter et al. (2019) independently suggested that the coastal shallow water may play a unique role to boost typhoon intensity during the landfall. The warm, vertically homogeneous shallow waters found in the northern coasts of the South China Sea and the Gulf of Mexico tend to significantly suppress the critical sea surface temperature (SST) cooling induced by the typhoon or hurricane. Therefore, the negative feedback of SST cooling was minimized, contributing to the rapid intensification during the landfall.This proposal is built on my recent work, i.e., Pun et al. (2019), to continue to investigate this new research topic thoroughly, from case study to systematic work, and then to long-term variation. Furthermore, the possible linkage to Taiwan will be studied too. Typhoon-ocean interaction has been a hot topic in the typhoon community. Taiwan is one of the leading countries in this field. It is believed that this proposal would yield some influencing results and papers, and thus contribute to the leading position of Taiwan.