Investigation of Atmospheric Turbulence Scales of Northeast Monsoons and Typhoons

• Main Authors: Bo-ChungChen, 陳柏中
• Other Authors: Jiun-Jih Miau
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/rdbrrz

碩士 === 國立成功大學 === 航空太空工程學系 === 105 === The aim of the present study is to investigate the atmospheric turbulence scales of northeast monsoons and two landed typhoons measured at different sites. The field measurements were made using a WindCube v2 wind Lidar. Mean wind speed, turbulence intensity and turbulent Reynolds stresses varied with respect to the time period and the representative periods were selected to further examinations. Time scales of turbulence fluctuations were integrated from the autocorrelation function to characterize atmospheric turbulence in different weather environment. Two northeast monsoon measurements show that both of the land-sea breeze and the surface roughness considerably affects the distributions of the longitudinal turbulence scales in the surface layer. However, atmospheric turbulence scales in typhoon winds are varied with respect to different stages in typhoon process. With the typhoons reaching the minimum atmospheric pressure, both of turbulence intensity and turbulent kinetic energy had the maximum values occurred near the surface layer, and significantly decreased with the vertical height. This feature is observed in the longitudinal distribution of Reynolds stress. Also the small-scale eddies predominated the turbulent behavior at the stage of wind speed decay.