Objective The primary goal of the programme of work is to investigate the physical and chemical processes involved in the exchange of air between the stratosphere and the troposphere in the extra-tropics through measurement campaigns and modelling studies. Idealised models will be used together with a mesoscale model and a general circulation model (GCM) as a means of identifying the dynamical and radiative processes that lead to irreversible stratosphere troposphere exchange (STE). The models will be validated by means of measurements campaigns carried out in synoptic situations identified as requiring further investigation, and by intercomparison between models. This will lead to an estimate of the flux of air and ozone from stratosphere to troposphere and vice versa. A chemical transport model will be used to investigate the effect of the transfer on the chemical balance of the troposphere and lower stratosphere.The work has been divided into 5 work packages (WPs) each of which will be led by a designated group who will monitor the progress of the work package, ensure that sufficient contact and co-ordination is maintained between the contributing groups and will be responsible for the work package reports. A series of 4 measurement campaigns will be carried out, using an airborne ozone lidar, ozone and temperature lidars, MST radars and ozonesondes in order to investigate processes involved in stratosphere troposphere exchange (STE) at mid-latitudes (WP2). The synoptic situations to be investigated will be determined with the aid of mechanistic modelling studies which will examine the important dynamical and radiative processes involved in STE and identify where additional measurements are required to test hypotheses and model predictions (WP1). Measurement campaign periods will be designated during which forecasts will be examined for suitable synoptic situations. Once identified a series of triggers will alert the measuring stations and the aircraft to ensure maximum sampling of the important regions. Analysis and interpretation of the measurements will be carried out in terms of the known synoptic situation (WP2). Detailed dynamical case studies will be carried out on two measurement campaigns, one of the previous TOASTE-B campaigns and one of the new TOASTE-C campaigns, using a mesoscale model and a full GCM to investigate the dynamical and radiative processes (WP3). Intercomparisons will be carried out between the models and the observations and between the mesoscale model and the GCM (WP3). Estimates of fluxes of air and ozone between the stratosphere and troposphere will be made (WP4). A full chemical investigation will be carried out of one of the measurement campaigns in order to investigate the effects of the fluxes of air, ozone and other pollutants on the chemical balance of the troposphere and lower stratosphere (WP5). Fields of science engineering and technologymechanical engineeringvehicle engineeringaerospace engineeringaircraftengineering and technologyelectrical engineering, electronic engineering, information engineeringinformation engineeringtelecommunicationsradio technologyradarnatural sciencesearth and related environmental sciencesatmospheric sciencesmeteorologytroposphere Programme(s) FP4-ENV 2C - Specific programme of research and technological development in the field of environment and climate, 1994-1998 Topic(s) 01020101 - Stratospheric chemistry and depletion of the ozone layer Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator COUNCIL FOR THE CENTRAL LABORATORY OF THE RESEARCH COUNCILS EU contribution No data Address Chilton OX11 0QX DIDCOT,HARWELL,CHILTON United Kingdom See on map Total cost No data Participants (5) Sort alphabetically Sort by EU Contribution Expand all Collapse all CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE France EU contribution No data Address Route des Gètines 92371 VERRIERES-LE-BUISSON See on map Total cost No data LUDWIG-MAXIMILIANS UNIVERSITY OF MUNICH Germany EU contribution No data Address Theresienstra?e 37 80333 Munchen See on map Total cost No data UNIVERSITAET KOELN Germany EU contribution No data Address Zuelpicher Str. 49 50674 KOELN See on map Total cost No data UNIVERSITY COLLEGE OF WALES ABERYSTWYTH United Kingdom EU contribution No data Address Penglais Campus, Cerediglon SY23 3BZ ABERYSTWYTH See on map Total cost No data University of Cambridge United Kingdom EU contribution No data Address Silver Street CB3 9EW Cambridge See on map Total cost No data