Abstract
The diurnal variation of wind in the atmospheric boundary layer over the Kanto plain is studied in order to find the contribution of each of the land-sea breeze and the diurnal variation of turbulence as a function of the magnitude of the larger-scale pressure gradient. The land-sea breeze is found to be the main source of the diurnal variation of wind when the pressure gradient is less than 5ms-1 in geostrophic wind speed. As the pressure gradient intensifies the land-sea breeze weakens and is replaced by a turbulence-induced diurnal variation, which dominates over the land when the pressure gradient exceeds 10ms-1.
