Analysis of Turbulence Parameters of Typhoon Morakot along the Southeast Coast of China

Abstract

The southeast coastal region of China is frequently affected by typhoons. The observation station was chosen to be located on the roof of Wenzhou University’s architectural engineering building to collect real-time wind speed data during the landfalling of Typhoon Morakot to investigate the properties of the near-ground wind field of typhoons. The turbulence characteristics of the near-ground wind and its variation with time intervals are analyzed on the basis of real-time measured data. The results show that the turbulence intensity only changes with the mean wind speed under relatively low wind speeds. The gust factors exhibit a scattered distribution under low wind speeds and tend to cluster together when the wind speed exceeds 8 m/s. With increasing time intervals, the turbulence intensity and the gust factor gradually decrease. The relationship between turbulence intensity and gust factor is obtained by the measured data and then compared with the empirical formulas. The peak factor remains constant while the mean wind speed changes, but diminish as the time intervals rise. The turbulence integral scale of typhoons slightly increases with the increasing mean wind speed, and its value falls between 70 and 150.

Keywords

• Typhoon Morakot
• wind characteristics
• field measurements
• turbulence intensity
• turbulence integral scale