Stratéole: A project to study antarctic polar vortex dynamics and its impact on ozone chemistry

The STRATÉOLE experiment is designed to study the wintertime Antarctic lower stratosphere polar vortex and its springtime breakdown. To this end, it is planned to fly a large number (around 200) of long-lived (3 months), small isopycnic drifting balloons instrumented with temperature and pressure sensors, GPS and transmitters. The main goal of STRATÉOLE experiment is to provide an unprecedented documentation of the wind field in the vicinity of the vortex edge in order to study vortex porosity and erosion, filamentation and mixing properties of the air masses. In addition, by the use of other sensors on some gondola, like radiometers and tuneable laser diodes, STRATÉOLE will also provide in-situ and/or column-integrated trace species measurements (like NO₂, O₃, CH₄, H₂O, aerosols...) and information on the radiation budget of the Antarctic lower stratosphere during this period. This will permit to obtain a better understanding of mechanisms responsible for ozone depletion occurring during the springtime vortex dilution.