Typhoon intensity change by ocean heat content in the Northwestern Pacific Ocean

A study of relationship between the typhoon intensity change and oceanic heat content was carried out. A typhoon-related oceanic heat content index was used to see how the typhoon intensity changes with the oceanic heat energy. The index was calculated by integrating the vertical temperature of the layer whose value is over 26degC, which is considered as a potential energy source for the typhoon to be intensified over the ocean. Especially during the summer season, even SST of all area shows higher than 29degC without horizontal gradient, the typhoon intensity is still rapidly changed (increase or decrease) over the ocean. In the results of comparison between the index and typhoon intensity(central pressure), the horizontal distribution of the index value matched well the typhoon intensity change pattern, showing that the typhoon was intensified after passing over the higher thermal energy area and weakened after passing the lower thermal energy area. The maximum value of decrease rate of central pressure per 6 hours was about 10% of the typhoon-related oceanic heat content index during the intensification period. The limitation in using this index to estimate the typhoon intensity is data availability, especially near the coastal area, since there is no real time temperature profile data.