The Third European Symposium on Polar Stratospheric Ozone Research

Schliersee, Bavaria, 18-22 September 1995.

The Symposium had two objectives. The first was a review of recent European research activities ; the second was to look forward by considering new directions in stratospheric research. More than 300 participants were involved in a stimulating week of discussion. DGXII of the European Commission and BMBF, who supported the meeting, are to be thanked.

A major component of the meeting was a discussion of the results of the SESAME (Second European Stratospheric Arctic and Mid-latitude Experiment) campaign. Eleven invited speakers covered topics ranging from a review of the stratospheric meteorology of recent Arctic winters, through measurement and interpretation related to O3, NOy and ClOy species, to measurements of UV-B and laboratory studies.

One day was devoted to a session on "New Directions in Stratospheric Research". Again the format involved four invited speakers and a wide-ranging discussion session.

The names of the speakers at the symposium are : B. Naujokat (review of meteorology), A. Engel (tracer measurements in SESAME), B. Stein (ground-based measurements of PSCs and aerosols), A. Adriani (aerosols), F. Arnold (NOy/NOx measurements), D. Toohey (ClOy measurements), F. Lefevre (NOy/ClOy modelling), C. Zerefos (total ozone), G. Vaughan (review of ozone measurements), M. Chipperfield (modelling of ozone), B. Gardiner (SESAME), A. Bais (UV-B intercomparisons), R. A. Cox (homogeneous chemistry), M. Rossi (heterogeneous chemistry), T. Peter (microphysics), G. Mégie (satellite research in atmospheric chemistry), P. Simon (measurements related to global change), P. Woods (new developments in instrumentation), J. Pyle (given by N. Harris due to absence) (new platforms for atmospheric research).

The poster sessions were a particularly important part of the meeting with more than 200 posters on display. Results from these sessions fed into a half-day open discussion on SESAME. A lot of exciting new work was presented ; here we highlight in particular three areas. The 1994/95 winter, when most of the SESAME activities took place, was very cold. As a consequence, polar stratospheric clouds were widespread and many different measurements of PSC properties were made. These provide insight into the formation of PSCs and their role in perturbing stratospheric chemistry. A number of measurements show that the vortex was denitrified : further analysis will increase our understanding of the poorly known processes by which denitrification occurs in the Arctic vortex. Last, great progress has been made in quantifying the chemical ozone loss which occurs in the Arctic vortex. Observations and models have been used to look at changes in both the column amount and in the vertical distribution of ozone. Extended abstracts (4-6 pages) of the posters are to be published in the EC Air Pollution Research Report series by DGXII.

For further information, contact
Dr. G. Amanatidis, European Commission DG XII/D-1, fax : +32 2 296 30 24
or
Dr. J. Pyle, European Ozone Research Coordinating Unit, fax : +44 1223 467390.

Neil Harris.