Developing a Coupled Modeling Framework to Investigate Antarctic Bottom Water Formation in Prydz Bay

The overarching goal of our research is to understand the significance of the polar ocean in the Prydz Bay region to the global climate system through estimating the formation and export of dense shelf water and illustrating the dynamic processes involved. Specific scientific questions that we seek to address include: (1) What are mechanisms that control circumpolar deep water (CDW) intrusions and its synoptic, seasonal and interannual variations? (2) What are the spatial/temporal variations in distributions of dense shelf water formed in the Prydz Bay shelf region? (3) What are the dynamic processes controlling the export and fate of the dense shelf water. We have developed a regional atmosphere-ocean-sea ice coupled system comprising the WRF, ROMS, and Budgell sea ice models to help answer these questions. We compare coupled and uncoupled hindcasts at 10 km horizontal grid spacing to demonstrate the importance of coupling when simulating (i) the local atmosphere-ocean-sea ice interactions that produce dense shelf water and (ii) the dynamic processes that control export off the shelf. Model analyses in conjunction with observations allow us to systematically examine the synoptic, seasonal and interannual variability of water masses on the shelf. By capturing contributions from sea ice formation, ice shelf melt water and CDW intrusion we are able to produce a better assessment of Antarctic bottom water formation. Preliminary results from our modeling effort will be reported in this presentation.