Between November 2025 and January 2026, the second field campaign of the European AWACA (Atmospheric Water Cycle over Antarctica) project took place in Antarctica. Its objective: to continuously measure key parameters of the water cycle (precipitation, cloud structure, and the isotopic composition of water vapor and precipitation) using innovative instruments. This project brings together French and Swiss laboratories, as well as the French Polar Institute, which is responsible for logistics.
During the first campaign (winter 2024–2025), four monitoring stations were deployed along a 1,100-km transect stretching from the coast to the interior of the continent. These sites (D17, D47, D85, and DC) enable the study of the dynamics of the water cycle in this region. The 2025–2026 campaign aimed to recommission these instruments for another year of data collection.
The GLACIO team at the LSCE is contributing to the project by measuring stable water isotopes in the atmosphere and precipitation using laser spectrometers adapted for Antarctic conditions. Each station has a self-contained container (OPU) equipped with a chimney to collect air and snowflakes, which are then fed into the spectrometers.
Inès Ollivier, a postdoctoral researcher at the LSCE, was responsible for maintaining the spectrometers. The mission began with 34 days at the D17 and D47 sites, where she repaired, recalibrated, and optimized the instruments (drying the sampling lines, adjusting the mirrors, and calibrating them under different humidity levels). The seven-person team lived in trailers pulled by tractors, traveling 100 km in two days to reach D47, often in difficult weather conditions (strong winds, blowing snow, reduced visibility).
The past three weeks have been devoted to the Concordia (DC) station, which is accessible by plane from the coast. Site D85, located halfway between the two, could not be reached and will be addressed during the next field season.
After four months on the mission, all objectives have been achieved. Learn more : awaca.ipsl.fr.