The Earth Science Colloquium Series presents:
Tropical Cyclone-Ocean Interaction: from Weather, Climate, to Global Warming
Dr. I-I Lin, Chair Professor, National Taiwan University.
Abstract: Tropical Cyclones are one of the most important natural disasters to humankind. Via complex TC-ocean interaction, the ocean provides energy to TC’s intensification. This talk covers 4 aspects of TC-ocean interaction: fundamentals, weather, climate, and global warming-scale applications.
1. Fundamentals: explaining the foundation concept of TC-ocean coupling, the importance of ‘Coupled SST’ vs. the conventional ‘Pre_TC SST’. Coupled SST is the ‘true SST’ which TCs really ‘felt’ during intensification. Six factors control the coupled SST: pre_TC SST, subsurface ocean temperature structure, salinity, TC wind speed, TC translation speed, and TC size. Accurate quantification of the coupled SST is the key to accurate quantification of ocean’s energy (air-sea fluxes) for TC’s intensification (Lin et al. 2021). Revision of theoretical TC intensification upper bound, Potential Intensity, to include ocean coupling contribution is also explained (Lin et al. 2013).
2. Weather-scale application: ocean and series of record-breaking TCs, as well as distinctions among the different cases are discussed. These important TC cases include Supertyphoon (STY) Haiyan (Lin et al. 2014), STY Hagibis (Lin et al. 2021), and killer-cyclone Nargis (Lin et al. 2009). As proposed in Lin et al. 2014, the need to add a new category, i.e., category ‘6’, to the existing TC intensity scale is highlighted.
3. Climate-scale application: explaining the climate origin of STY Haiyan, as well as ENSO-ocean-TC intensity relationship. Not only the conventionally-understood relationship between very intense TCs and El Niño, La Nina or La Nina-like condition can also nurture some of the most intense TCs, e.g., STYs Haiyan and Megi (Lin et al. 2014; Zheng et al. 2015; Lin Camargo et al. 2020).
4. Global-warming scale application: including marine heat wave (Pun et al. 2023), ocean stratification change (Huang et al. 2015), TC translation speed change (Chang et al. 2020), and poleward migration (Lin, Camargo et al. 2023).
Host: Dr. Chia-Ying Lee, Lamont Associate Research Professor, Ocean and Climate Physics.
