OSIRIS observations of a tongue of NOx in the lower stratosphere at the Antarctic vortex edge: comparison with a high-resolution simulation from the Global Environmental Multiscale (GEM) model

Abstract

Selected NOx profiles of the Antarctic lower stratosphere inferred from OSIRIS NO2 observations are presented from the austral spring of 2003. These observations show a tongue of NOx at 100 hPa, with a concentration typical of the middle stratosphere. Simulations with the Global Environmental Multiscale model show that this small-scale tongue of NOx-rich air descended into the lower stratosphere. The tongue was formed as a result of a Rossby wave breaking days earlier, transporting NOx from the pole, where larger concentrations had recently appeared, to the edge of the vortex. The three-dimensional structure of the breaking wave is illustrated in detail. PACS Nos.: 92.60.hf, 92.60.Xg, 93.30.Ca