Raw data from Ran AUV missions ANA14B_01, ANA14B_02 and ANA14B_03 performed during the ANA14B RVIB Araon expedition to the Amundsen Sea

The West Antarctic Ice Sheet (WAIS) is considered the greatest remaining uncertainty for predicting future global sea level rise. It is drained by glaciers that terminate in the ocean, where they form floating ice shelves overlying vast sub-ice cavities. There is a pronounced data gap for these systems - most of the Antarctic ice shelves have never been sampled in situ. As a result there is a shortage of understanding and quantification of relevant processes and control mechanisms. The main heat reservoir threatening the ice shelves is a warm salty water mass that, due to its high density, lies deep in the Southern Ocean. The total heat content of this water mass is equivalent to warming the entire atmosphere over Antarctica to 400oC. Earth’s rotation and the continental shelf break prevents the water from flooding the shelf and it only reaches the glaciers aided by wind and/or where submarine troughs connect to the ocean. Research about the ocean processes that deliver heat to the WAIS will be developed based on new data sets. An autonomous underwater vehicle with long range and the capability of navigating beneath ice shelves will make formerly impossible observations in two key WAIS ice shelves. These will be supplemented by moorings on the seabed that measure ocean currents over time - at the end of the project, several 20 year time series. The data sets will be interpreted based on theoretical bounds for heat flux into the ice shelf cavities, developed in parallel.

The largest block of ice on Earth, the Antarctic ice sheet, covers more than 14 million square kilometres. Its fate rests on how fast we can stop Earth from warming. Melting would cause a catastrophic sea level rise. The EU-funded OCEAN ICE project will improve assessments of the impact on the European climate from the melting ice sheets. It will develop a sheet-climate model that can be used to predict how changes in the Antarctic and Greenland ice sheets impact global climate. On the basis of existing data, the project will formulate new estimates of ice sheet melt and the impact on ocean circulation.