Abstract

We analyzed the variations in the mean wind field, turbulence, and turbulent flux at the landfall sites of three typhoons using observational data obtained from an offshore monitoring platform. These variations were different for onshore and offshore winds. The turbulent fluctuation intensity and friction velocity increased with wind speed both before and after landfall. However, the turbulent flow decreased with increasing wind speed during landfall. The relationships between the friction velocity and drag coefficient and the wind speed were affected by whether the typhoon makes landfall, and the relative position of the landfall site of the typhoon and the observation site.