Abstract
The vertical turbulent diffusivity Kz in the atmospheric boundary layer was calculated from the trajectory data of the South Kanto Plain Project, the Akita Bay Area Experiment, and the Eastern Tennessee Trajectory Experiment, on the basis of the statistical theory of turbulence. And the seasonal and topographical effects affecting the diurnal variation and profile of Kz were investigated.
In consequence, it was found as expected that Kz has a diurnal variation like a sine curve without regard to season or topography. It can be conjectured that the phase of diurnal variation is affected by the possible duration of sunshine, and the amplitude by topography and stability of the atmospheric boundary layer.
The maximum vertical turbulent diffusivity Kmax was observed within the region of 0.15≤z/zi<0.50 on the Kz profiles throughout the whole data. And zm at which Kmax was observed differed with season and topography.
