Yann-Treden TRANCHANT (University of Tasmania, Australia); Ash PARKER (CSIRO, Australia); Bea PENA-MOLINO (CSIRO, Australia)

The FOCUS (Fine-scale Observations of the Antarctic Circumpolar Current Under SWOT) project is a regional validation study conducted in support of the SWOT mission. FOCUS targeted an energetic region of the Antarctic Circumpolar Current thought to contribute disproportionately to meridional heat transport and ocean ventilation. A voyage on the R/V Investigator collected data with CTD casts, towed profiler and deployed multiple ocean gliders, floats, and drifters it also deployed a 3.4km tall mooring. The mooring was recovered in May 2025 and has 18month of data under heavy SWOT coverage during the period. This presentation will focus on this longer-term observation dataset and show the temporal variability and the vertical extent of features observed by SWOT snapshots and passing through the mooring. At the time of this abstract submission the Mooring data have not been quality processed, but the first checks indicate we have a rich dataset with higher resolution in the top 1000m of the water column and the bottom 500m. The mooring was designed and instrumented to sustain the strong variability (+-2m/s) in current and properties right at the polar front. The temporal variability with depth will be characterised and put in perspective of SWOT spatial variability. The flow equilibration analysed in concomitance with other voyage datasets and related analysis and the high-resolution FOCUS model (Tranchant et al.) to describe the finer scale dynamics at the polar front.