the SUNITE DC projet will follow the same scientific objectives fixed during the previous program, i.e. document and use of the sulfate and nitrate stable isotopes in the context of an anticipated ozone hole recovering to put new constrains on the sources, transformations and transports of these species into polar regions where there are archived in ice for hundred thousand of years. However, the methodologies and approaches will evolve toward monitoring activities instead of intensive summer campaigns. The scientific activities will concentrate on the monitoring of the aerosol and surface snow isotope composition year-round with the double objectives of allowing the comparison of long isotope series with the recovering and dynamic of the stratospheric ozone and to secure continuous monitoring in case a major event will occur (e.g. major volcanic eruption, solar proton event, major ENSO etc.) .