Lagrangian Match Chemical Loss Calculations and Related Diagnostics for Aura MLS

Accurate quantification of chemical destruction of stratospheric ozone each Arctic winter/spring requires a full understanding of the impact of dynamics on the temporal evolution of high latitude ozone profiles. Transport phenomena, including descent and the exchange of air between the polar vortex and lower latitudes, lead to changes in ozone abundance that must be disentangled from those due to chemical destruction. Such ozone loss quantification is important for identifying and characterizing the different stages of ozone layer recovery. We present a new application of the "Match" technique - originally developed for ozonesonde observations - to daily global ozone profile measurements from NASA's Aura Microwave Limb Sounder (MLS), launched in 2004. Lagrangian trajectories are used to identify cases where the same airmass is observed by MLS on multiple successive days. The decline in ozone abundance between selected successive "matched" observations gives a measure of chemical destruction. The dense MLS daily coverage enables significantly more matches to be catalogued than is possible for sonde-based studies. Results from this analysis will be compared to findings from previous studies, and the application of the technique to species other than ozone will be discussed. Other applications of the MLS Lagrangian Trajectory Diagnostics, upon which this work is based, will also be described.