The impact of base-level analyses on stratospheric circulation statistics for the Southern Hemisphere

Abstract

The impact of different base-level analyses on derived stratospheric circulation statistics for the Southern Hemisphere has been assessed. Three different sets of daily operational analyses of geopotential height at 100 hPa for September, 1981 have been used as the base-level analyses, combined with a single set of daily thickness analyses for the stratosphere. The circulation statistics considered include mean fields, transient eddy statistics, Eliassen-Palm flux diagnostics and vorticity fields. In general, the different base-level analyses do not change the qualitative description of the circulation statistics but they lead to marked quantitative differences, particularly at high latitude..