The program is aimed to characterize and understand the chemical composition and future evolution of the lower boundary layer on the high Antarctic plateau at Concordia Station. Long term monitoring of ozone and other acidic trace gases in proposed with focus on two specific axes: 1. Evolution of ozone ground level and, more generally, of the atmosphere oxidative capacity in response to future recovery of the stratospheric ozone. 2. Improve our actual understanding of the specific oxidative capacity of the high Antarctic plateau by the monitoring of acidic gases since some of them are linked to intense photochemical processes above and within the snowpack.