Sensitivity of simulated water mass transformation on the Antarctic shelf to tides, topography and model resolution

Water mass transformation (WMT) around the Antarctic margin controls Antarctica Bottom formation and abyssal limb of global meridional overturning circulation, besides mediating ocean-ice shelf exchange, ice sheet stability its contribution to sea level rise. However, mechanisms controlling rate WMT in are poorly understood due lack observations inability climate models simulate those mechanisms, particular beneath floating shelves. We used a circum-Antarctic model assess surface fluxes, mixing, interaction on continental shelf. The salt budget dominates rates, with only secondary from heat budget. Basal melt shelves drives buoyancy gain at lighter density classes (27.2<σ θ < 27.6 kg m -3 ), while input associated sea-ice growth coastal polynyas loss heavier densities (σ > 27.6). found large sensitivity rates horizontal resolution, tides topography within Filchner-Ronne, East West cavities. In Filchner-Ronne Ice Shelf, an anticyclonic circulation front Ronne Depression regulates basal melting/refreezing is substantially affected by resolution. Model resolution also affect Slope Current both Antarctica, impacting on-shelf delivery, WMT. Moreover, representation draft impacts freezing temperature thus Antarctica. These results highlight importance resolving small-scale features flow topography, include effects tidal forcing, adequately represent water transformations that directly influence circulation.