Our session “Dynamics and chemistry of the upper troposphere and stratosphere: observations and models” is a long-running element of the AS programme. This year we will have a focus on the role of the global UTLS and tropopause region for dynamics and composition. We particularly invite studies focusing on links between observations and measurements and the dynamical processes relevant for long-term trends.
We therefore particularly encourage joint observational and model based studies, combining recently collected in-situ and/or remote sensing observations with model simulations.

Solicited speaker is Wolfgang Steinbrecht from the German Weather Service, who will give an overview about the latest results from the long-term observations of ozone in the UTLS and the stratosphere.

We are also hosting a block on "SAGE III/ISS Science Results and Comparison to Related Stratospheric Composition Measurements", convened by David Flittner together with Sophie Godin-Beekmann, Adam Bourassa and Richard Eckman.