Diffusion coefficients derived from the Lagrangian statistics

Diffusion coefficients are derived from trajectory analyses. Derived horizontal diffusivity in the lower stratosphere varies with season and confirmed the results obtained in YAMAZAKI (Proc. NIPR Symp. Polar Meteorol. Glaciol., 1,39,1987). Large horizontal diffusivity appears in the region of enhanced wave activity and/or weak zonal wind. The horizontal and vertical diffusivities in the troposphere are large in middle latitudes. The pattern and magnitude of derived diffusivity generally agree with the results of GFDL General Circulation/Transport Model by PLUMB and MAHLMAN (J. Atmos. Sci., 44,298,1987). Dispersion from the antarctic troposphere is very rapid and the residence time over Antarctica is about 3 days