The CAPOXI 35-75 project aims to document the oxidative capacity of the southern hemisphere following a North-South latitudinal gradient, from the Amsterdam Island (37°S) to the Concordia station (75°S), including the Dumont d’Urville coast station (67°S). The program will specifically be dedicated to solve few inconsistencies observed these past few years in Antarctica. If the high oxidative capacity of the Antarctic plateau atmosphere is a well established phenomena, induced by the snow emission of nitrogen oxides, it is however difficult to reconcile our current knowledge of the oxidation schemes with the ground observations. Such discrepancies strongly limit our capacity to understand to ice core records. In this program, we propose to revisite some of the key parameters governing of the oxidation state of the atmosphere. By managing scientific stations from 37 to 75°C, IPEV offers the unique opportunity to study the oxidative capacity in very contrasting environments that will ease to reveal the different interaction between reactive species. The project will focus on the nitrogen oxides and halogen species in direct link with the ozone budget and will benefits from international collaboration to access specific instrumentation and modelling tools not available in our group.