Contribution of Prydz Bay Shelf Water to Antarctic Bottom Water Formation

Antarctic Bottom Water (AABW) formation is a key component in setting the global thermohaline (overturning) circulation. Recent studies infer a reduction of the AABW component from reduced volume of AABW entering global deep ocean basins around the Antarctic continent. It is important to obtain better estimates of AABW production rate in its source areas, and to investigate whether the global overturning circulation is slowing down. The project will continue fieldwork with CTD/LADCP surveys including 2 yearly repeat sections, mooring recoveries and deployments. Seasonal-interannual variability of CDW intrusion, dense shelf water accumulation and export as well as overflow from the Prydz Bay shelf will also be observed. The Prydz Bay- Amery Ice Shelf region has been suggested as a key AABW production site. USAP access to this remote region of the Antarctic continent is challenging. The project will involve fieldwork to be carried out with Danish and Chinese collaboration aboard the Chinese research vessel, Xue Long. A high-resolution regional ocean-sea ice coupled model will be developed to allow time and space continuous three-dimensional ocean state estimation. Both in-situ and remote sensing observations along with the modeling simulation results will be used to investigate (i) the local atmosphere-ocean-sea ice interaction and shelf processes that produce dense shelf water and (ii) the dynamic processes that control the shelf water export.