As in previous years we invite presentations that cover the whole spectrum of upper tropospheric and stratospheric composition-climate interactions research. Measurement and modelling (or a combination of both) studies are equally welcome. Notwithstanding the general nature of the session, we would also like to invite presentations that are immediately related to two recent activities in the community: the so-called 'lifetime assessment' (a re-evaluation of the lifetimes of dominant stratospheric ozone depleting substances in the framework of SPARC) and the first two HALO flight campaign (Transport and Composition in the Upper Troposphere/Lowermost Stratosphere; TACTS, and Earth System Model Validation; ESMVAL).

Solicited speakers are Andreas Engel and Stefan Reimann.

We would also like to draw your attention to a townhall meeting organised by the European Climate Research Alliance (ECRA) that will discuss how we can contribute to shaping the future of climate research in Europe. We look forward receiving your contribution!