ドップラーライダーの鉛直風速観測に基づく都市大気境界層内乱流スケールの推定 [in Japanese] STRUCTURE OF TURBULENCE IN THE URBAN ATMOSPHERIC BOUNDARY LAYER DETECTED IN THE DOPPLER LIDAR OBSERVATION [in Japanese]
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Doppler lidar observation was conducted to investigate the statistical and structural characteristics of the atmospheric boundary layer (ABL) over urban area, Koganei, Tokyo, on 21 February 2010. Vertical distribution of the vertical velocity was measured at the height between 150 m to about 2,000 m from the ground with a constant interval of 76 m. The potential temperature (PT) profiles were also measured by radiosonde. Vertical velocity spectra in the ABL show two dominant time scales; one is about 15 minute, and the other is less than 5 minutes. The higher frequency motion extends up to the top of ABL determined by PT profiles, which would be attributed to the individual thermal plumes. The lower frequency motion penetrates into the capping inversion. This would be the contribution of the organized thermal cells which propagates into the capping inversion as gravity wave during daytime. Surface layer depth was estimated about 300 m. It is due to the enhanced mechanical production of turbulence in urban roughness.
- Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering)
Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering) 67(4), I_313-I_318, 2011
Japan Society of Civil Engineers