AWACA (Atmospheric WAter Cycle over Antarctica : Past, Present and Future)

Climate models predict that precipitation will increase in Antarctica, which will moderate global sea-level rise. Meanwhile, the isotopic composition of snowfall records climate parameters which can be recovered in ice cores. However, there are still major gaps in our understanding of the atmospheric water cycle over Antarctica. For the first time, the AWACA project willprovide a consistent and comprehensive combined observation and modeling framework to understand and predict the fate of atmospheric water all along the tropospheric column. Specifically adapted/designed instruments will be combined to form observation platforms deployed at 5 sites along a 1100 km coast-to-plateau transect aligned with the typical moisturecarrying air mass trajectories. The challenges of working in full autonomy in Antarctica, never addressed to such an extent before, will be tackled by collaborating with experts in polar technology and logistics. The resulting data set will make possible the study of the processes driving the water fluxes and composition to an unprecedented level, and the gained insights will be a strong basis to develop new physics parameterizations for regional and climate models. Once validated along the transect but also in other regions of Antarctica thanks to satellite observations and past campaigns, those models will enable us to decipher the past and future variability of the atmospheric water cycle over Antarctica.