Accurate prediction of typhoon intensity is important to reduce damage caused by typhoons. Heating and cooling due to radiative processes in clouds are hypothesized to affect typhoon intensity in terms of changing the temperature structure of the atmosphere. In recent years, simulation experiments have investigated the relationship between radiative processes and typhoon intensity, but it is still remained to be answered how and to what extent radiative processes control typhoon intensity.

In this study, simulation and sensitivity experiments on radiation processes were conducted for Typhoon Tip (1979), which recorded the lowest central pressure ever since 1951, to investigate differences in the dynamic and thermodynamic structure of the typhoon.

The lowest central pressure of the typhoon was 17 hPa higher when the radiation process was included in the model, suggesting that the radiation process suppressed the intensity of the typhoon. When the radiative process is considered, the temperature structure of the atmosphere inside the typhoon changes due to heating/cooling by the radiative process, and the radial temperature gradient in the inner core region is smaller than when the radiative process is not considered. The relationship between the temperature gradient and the pressure gradient suggests that the pressure gradient in the radial direction is smaller than when the radiative process is not considered, which suppresses the strengthening of the low level inflow, resulting in relatively weaker typhoon intensity. Thus, it is shown that radiative processes due to cloud and water vapor affect typhoon intensity through several stages.