[19-May-2026] Yu, L. This talk focuses on four main themes (1) How salinity’s role changes with scale, i.e., from tracing the water cycle to shaping frontal density gradients; (2) salinity-driven frontal dynamics near O(10 km) and our ability to resolve it by current satellite salinity; (3) submesoscale thermohaline front types and their implications for vertical exchange, productivity, carbon cycling, and Earth system model fidelity; (4) the missing dimension O(10–20 km) SSS may add to SWOT, SST, and PACE observations of ocean fronts.