DOVuFRIS · Detecting Ocean Variability under Filchner-Ronne Ice Shelf

Detecting Ocean Variability under Filchner-Ronne Ice Shelf

Ice shelves, the floating extension of the Antarctic Ice Sheet, help stabilise the ice sheet by hindering the flow of grounded ice into the ocean. At their extensive base, ice shelves are exposed to the heat delivered by the oceans, and as this heat delivery changes, so does the rate at which ice shelves melt. Ultimately, changes in the heat delivery to the ice shelves can lead to changes in ice-sheet flow and in the rate at which ice mass is discharged from the continent into the ocean. Ice-shelf cavities are challenging environments to observe, because of their remote locations and extreme climate conditions. As a result, the knowledge of the temporal variability and trends that the ocean underneath experiences are largely unknown. Exploration of the way oceanic variability expresses itself by its signature in the rate of melting at the ice-shelf base has started with the recent development of the autonomous phase-sensitive radio-echo sounder (ApRES) by the British Antarctic Survey. ApRES is able to detect small changes inside the ice shelf and at its base and the primary outcome from its measurement is a time series of basal melt rates. However, the measurement ApRES provides is indirect and there are a number of difficulties that arise and need to be overcome. The primary purpose of the MSCA Individual Fellowship DOVuFRIS was to analyze and explore the full potential of the first extensive collection of ApRES data. There are three main objectives that DOVuFRIS addressed. The first was to determine the extent of oceanographic temporal variability under the Filchner-Ronne Ice Shelf. The second aimed to identify and investigate the physical mechanisms governing this oceanic variability and the significance of this variability for the overall state of the ice-shelf cavity. The third objective was to make these ApRES-derived data useful for ocean modellers that attempt to design realistic simulations of sub-ice-shelf cavities.

Data: CORDIS, © European Union