APPLICATION OF A PLANETARY WAVE BREAKING PARAMETERIZATION TO STRATOSPHERIC CIRCULATION STATISTICS

The planetary wave parameterization scheme developed recently by Garci a is applied to stratospheric circulation statistics derived from 12 y ears of National Meteorological Center operational stratospheric analy ses. From the data a planetary wave breaking criterion [based on the r atio of the eddy to zonal mean meridional potential vorticity (PV) gra dients], a wave damping rate, and a meridional diffusion coefficient a re calculated. The equatorward flank of the polar night jet during win ter is identified as a wave breaking region from the observed PV gradi ents; the region moves poleward with season, covering all high latitud es in spring. Derived damping rates maximize in the subtropical upper stratosphere (the ''surf zone''), with damping time scales of 3-4 days . Maximum diffusion coefficients follow the spatial patterns of the wa ve breaking criterion, with magnitudes comparable to prior published e stimates. Overall, the observed results agree well with the parameteri zed calculations of Garcia.