Sensitivity of simulated water mass transformation on the Antarctic shelf to tides, topography and model resolution
| Autor: | Boeira Dias, Fabio, Rintoul, Stephen R., Richter, Ole, Galton-Fenzi, Benjamin Keith, Zika, Jan D., Pellichero, Violaine, Uotila, Petteri |
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| Přispěvatelé: | Institute for Atmospheric and Earth System Research (INAR) |
| Jazyk: | angličtina |
| Rok vydání: | 2023 |
| Předmět: |
Ice shelf cavities
Global and Planetary Change Antarctic shelf Ocean Engineering Coastal polynyas Aquatic Science Oceanography 114 Physical sciences high salinity shelf water (HSSW) Water mass transformation Ocean-ice shelf interaction ice shelf water (ISW) Southern Ocean Water Science and Technology |
| Zdroj: | XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
| Popis: | Water mass transformation (WMT) around the Antarctic margin controls Antarctica Bottom Waterformation and the abyssal limb of the global meridional overturning circulation, besides mediatingocean-ice shelf exchange, ice sheet stability and its contribution to sea level rise. However, themechanisms controlling the rate of WMT in the Antarctic shelf are poorly understood due to thelack of observations and the inability of climate models to simulate those mechanisms, particularlybeneath the floating ice shelves. We used a circum-Antarctic ocean-ice shelf model to assessthe contribution of surface fluxes, mixing, and ocean-ice shelf interaction to the WMT on thecontinental shelf. The salt budget dominates the WMT rates, with thebasal melt of ice shelves driving buoyancy gain at lighter density classes andsalt input at coastal polynyasdriving buoyancy loss at heavier densities. We found a considerable sensitivity of the WMTrates to model horizontal resolution, tides and topography within the Filchner-Ronne, East andWest Antarctica ice shelf cavities. In the Filchner-Ronne Ice Shelf, an anticyclonic circulation infront of the Ronne Depression regulates the rates of basal melting/refreezing and WMT and issubstantially affected by tides and model resolution. Model resolution is also found to affect theAntarctic Slope Current in both East and West Antarctica, impacting the on-shelf heat delivery,basal melt and WMT.These results highlight the importance of resolving tides and small-scale features of the flowand topography to adequately represent water masstransformations on the shelf that directly influence the abyssal global overturning circulation. The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) |
| Databáze: | OpenAIRE |
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