WHOI PO
Viviane Menezes, WHOI - Solving a 50-year-old mystery with new technology: Insights from Deep SOLO floats on the journey of Bottom Water through the Fracture Zones of the Southwest Indian Ridge
| Date |
Time |
Location |
| January 28th, 2025 |
3:05pm-4:05pm |
Clark 507 |
Title: Solving a 50-year-old mystery with new technology: Insights from Deep SOLO floats on the journey of Bottom Water through the Fracture Zones of the Southwest Indian Ridge
Abstract: The only pathway for Antarctic Bottom Water (AABW) to ventilate the entire western Indian Ocean as part of the Global Overturning Circulation is the deep fracture zones of the Southwest Indian Ridge. Due to the scarcity of observations in this area, AABW presence has only been well established in one of these fracture zones: the Atlantis II (first detected in the 1970s). In May 2023, the Deep Madagascar Basin Experiment (DMB) deployed three Deep SOLO floats rated to 6000 dbar in the exit of the fracture zones that were more likely to transport AABW given the current knowledge of bottom topography: Atlantis II, Novara, and Melville. Distinct from the future global array and current regional arrays, these floats have been operating over very rough topography, collecting temperature and salinity profiles with high temporal and vertical resolutions in the deep ocean. In the present talk, we discuss the calibration of salinity measurements from Deep SOLOs and revisit the half‐century puzzle about the contributions of the different fracture zones. The floats find AABW signature in both Melville and Novara fracture zones, not only in Atlantis II. This is the first time the Novara contribution has been revealed. The floats also uncover their distinct properties, which may result from the different mixing histories. DMB shipboard observations complement the float data.