A 2-D model simulation of downward transport of NOy into the stratosphere: Effects on the 1994 austral spring O-3 and NOy

Simulations using SAMPEX and HALOE data suggest that NOy produced by thermospheric processes and by relativistic electron precipitation in the mesosphere and lower thermosphere have been important to stratospheric NOy and O-3 during the austral spring in 1994. The relative importance of the two NOy sources is discussed. The results are supported by an analysis of HALOE NOy and CH4 data during October 1994 and are in agreement with ATMOS NOy observations made in November 1994.