Long-term DIAL monitoring of the stratospheric ozone vertical distribution

DIAL lidars are widely used for the monitoring of stratospheric ozone in the framework of the NDSC (Network for the Detection of Stratospheric changes). Long term DIAL ozone measurements have been performed in the South of France at Observatoire de Haute-Provence (OHP - 43.91degreesN, 5.71degreesE) since 1986 and in Antarctica in Dumont d'Urville (66.4degreesS, 140degreesE) from 1991 to 2000. At OHP, the measurements allow the study of the short-term and long-term variability of stratospheric ozone in the northern mid-latitude regions. They have been used recently to evaluate the influence of Arctic ozone depletion on mid-latitude ozone amounts. In Antarctica, the lidar measurements allowed the evaluation of the air subsidence in autumn and the ozone loss linked to anthropogenic halogen compounds in spring. Due to the location of the Dumont d'Urville station close to the edge of the polar vortex, a detailed study of the permeability of the polar vortex as a function of altitude could be performed. In addition to long term measurements, an airborne ozone lidar was deployed to sample polar air filaments mixing into mid-latitude regions. These measurements validated high resolution transport models used to evaluate at global scale the influence of polar ozone depleted air on mid-latitude ozone trends.