Investigating air-sea interactions


The Southern Ocean is characterized by diverse weather systems, which lead to severe weather conditions – heavy precipitation, wind storms, fog –  and impact ocean evaporation, the water budget of the remote islands, and Antarctic precipitation. Quantifying these processes and their interplay is essential for understanding Earth’s climate. Stable water isotopes (SWI), which occur naturally in the ocean, land surface waters and the atmosphere, can be used as tracers of the complex processes that govern the global and regional water cycle.

Therefore, we will measure SWI in atmospheric vapour during the ship cruise and observe the variability of precipitation events with a micro-rain radar. Liquid samples will be collected from precipitation events, from the ocean and from accessible surface waters on the islands. Together with trajectory-based analysis methods, these observations provide a unique opportunity to investigate the variability of ocean evaporation conditions as recorded in SWI signals in vapour, the variability of precipitation processes revealed by the radar and combined SWI measurements in vapour and precipitation, and oceanic source conditions of water that is later deposited in Antarctic ice cores.

Principal Investigator (PI)

Heini Wernli

Institute for Atmospheric and Climate Science, ETH Zürich, Switzerland


Investigation of air-sea interaction in the Southern Ocean from stable water isotope measurements

Principal institution / country

  • EPFL (Switzerland)
  • University of Bergen (Norway)
  • Lund University (Sweden)