11:15 〜 11:30
[AAS05-07] Impact of Sea Surface Evaporation on Developing Tropical Cyclone: Numerical simulation study of Typhoon Faxai(2019)
キーワード：台風、数値シミュレーション、水蒸気、熱帯低気圧
A project ”Moonshot Goal 8” was established to study the possible weakening of typhoon intensity due to artificial interventions supported by Japan Science and Technology Agency.
We are considering how to reduce the evaporation of water vapor from the sea surface to suppress the intensification of tropical cyclones(TC).
Thus, we are developing the surfactant to be sprayed under or around TC.
The previous studies suggested that the enthalpy transfer coefficient (CK) is almost constant or increases slightly at high wind speeds.
Nevertheless, a limited number of studies have reported on the effects of CK on TC intensity, especially realistic case studies.
Therefore, this study aims to investigate the relationships between CK and realistic TC intensification under numerical simulations to verify the possibility of modification.
We focused on the intensification of Typhoon Faxai in 2019, which caused large damage to the Kanto region in Japan.
In this study, sensitivity experiments with directly changing water vapor flux from the sea surface around Faxai were conducted by the Scalable Computing for Advanced Library and Environment (SCALE).
We tested the control run (CTL) and 5 sensitivity experiments in which water vapor flux decreased by 10% from 90% to 50% around a 200 km radius area moved with the center of Faxai every timesteps.
The resultant intensification of Faxai was sensitive.
These were reduced almost linearly and weakened by about 10% CTL when set to 50% water vapor flux 200km from the center in CTL.
However, it was insensitive to the area of reducing the amount.
From 25 km to 150 km radius, the maximum windspeed was reduced linearly over 10% and almost same between 150km and 200km.
We will conduct further studies until the meeting.
We are considering how to reduce the evaporation of water vapor from the sea surface to suppress the intensification of tropical cyclones(TC).
Thus, we are developing the surfactant to be sprayed under or around TC.
The previous studies suggested that the enthalpy transfer coefficient (CK) is almost constant or increases slightly at high wind speeds.
Nevertheless, a limited number of studies have reported on the effects of CK on TC intensity, especially realistic case studies.
Therefore, this study aims to investigate the relationships between CK and realistic TC intensification under numerical simulations to verify the possibility of modification.
We focused on the intensification of Typhoon Faxai in 2019, which caused large damage to the Kanto region in Japan.
In this study, sensitivity experiments with directly changing water vapor flux from the sea surface around Faxai were conducted by the Scalable Computing for Advanced Library and Environment (SCALE).
We tested the control run (CTL) and 5 sensitivity experiments in which water vapor flux decreased by 10% from 90% to 50% around a 200 km radius area moved with the center of Faxai every timesteps.
The resultant intensification of Faxai was sensitive.
These were reduced almost linearly and weakened by about 10% CTL when set to 50% water vapor flux 200km from the center in CTL.
However, it was insensitive to the area of reducing the amount.
From 25 km to 150 km radius, the maximum windspeed was reduced linearly over 10% and almost same between 150km and 200km.
We will conduct further studies until the meeting.