Spectrum analysis of the vertical and horizontal velocity fluctuations above the city center and evaluation of the effects on temperature near the ground

Abstract

For effective use of the sea breeze as a countermeasure against urban warming, it is important to analyze the wind field within the atmospheric boundary layer over the city and clarify the relationships between the sea breeze above the city and the temperature near the ground, in summer. In this study, a concurrent measurement of wind velocities using two Doppler lidars in the city center, and the air temperature at multiple observation points was conducted in coastal city Sendai, Japan. The characteristics of vertical and horizontal wind velocity fluctuations of sea breezes were analyzed quantitatively by spectrum analysis, and the effects on temperature were analyzed.