Direct Numerical Simulation is performed to study the dissolution/melting process of sloping ice-... more Direct Numerical Simulation is performed to study the dissolution/melting process of sloping ice-shelves at fixed ambient salinity and temperature. A series of numerical simulations are carried out over various inclinations of the ice block with the horizontal direction. Both laminar and turbulent flows are simulated over shallower slopes. When the boundary layer is laminar, dissolution-rate varies along the slope-length, which decreases in the upslope direction. Dissolution rate is independent in the upslope direction when the boundary layer becomes turbulent. These results are geophysically relevant and can be developed further towards a better parametrisation scheme for the GCMs to estimate the ice-loss around Antarctica.
Effects of stratification on the dissolution of a vertical ice-face: effect of Rayleigh number Bi... more Effects of stratification on the dissolution of a vertical ice-face: effect of Rayleigh number Bishakhdatta Gayen, Mainak Mondal and Ross W. Griffiths Research School of Earth Science, The Australian National University, Canberra, Australia Numerical simulation is performed to investigate the effect of ambient stratification on a vertical ice face dissolving into cold and saline water. The three coupled interface equations are used, along with the Boussinesq and non-hydrostatic governing equations of motion and equation of state for seawater, to solve for interface temperature, salinity and melt rate. The main focus is on the rate of dissolving of ice at ambient water temperatures between 0 ◦ C and 4 ◦ C and salinity around 35 psu and the dependence on stratification (as characterizes many sites around Antarctica). In order to examine the process and scaling we use very strong stratification and vertical scales much less than those in the oceans. Figure 1: (a) The formation of doubl...
The effects of the slope of an ice–seawater interface on the mechanisms and rate of ablation of t... more The effects of the slope of an ice–seawater interface on the mechanisms and rate of ablation of the ice by natural convection are examined using turbulence-resolving simulations. Solutions are obtained for ice slopes $\unicode[STIX]{x1D703}=2^{\circ }{-}90^{\circ }$, at a fixed ambient salinity and temperature, chosen to represent common Antarctic ocean conditions. For laminar boundary layers the ablation rate decreases with height, whereas in the turbulent regime the ablation rate is found to be height independent. The simulated laminar ablation rates scale with $(\sin \unicode[STIX]{x1D703})^{1/4}$, whereas in the turbulent regime it follows a $(\sin \unicode[STIX]{x1D703})^{2/3}$ scaling, both consistent with the theoretical predictions developed here. The reduction in the ablation rate with shallower slopes arises as a result of the development of stable density stratification beneath the ice face, which reduces turbulent buoyancy fluxes to the ice. The turbulent kinetic energy ...
Direct Numerical Simulation is performed to study the dissolution/melting process of sloping ice-... more Direct Numerical Simulation is performed to study the dissolution/melting process of sloping ice-shelves at fixed ambient salinity and temperature. A series of numerical simulations are carried out over various inclinations of the ice block with the horizontal direction. Both laminar and turbulent flows are simulated over shallower slopes. When the boundary layer is laminar, dissolution-rate varies along the slope-length, which decreases in the upslope direction. Dissolution rate is independent in the upslope direction when the boundary layer becomes turbulent. These results are geophysically relevant and can be developed further towards a better parametrisation scheme for the GCMs to estimate the ice-loss around Antarctica.
Effects of stratification on the dissolution of a vertical ice-face: effect of Rayleigh number Bi... more Effects of stratification on the dissolution of a vertical ice-face: effect of Rayleigh number Bishakhdatta Gayen, Mainak Mondal and Ross W. Griffiths Research School of Earth Science, The Australian National University, Canberra, Australia Numerical simulation is performed to investigate the effect of ambient stratification on a vertical ice face dissolving into cold and saline water. The three coupled interface equations are used, along with the Boussinesq and non-hydrostatic governing equations of motion and equation of state for seawater, to solve for interface temperature, salinity and melt rate. The main focus is on the rate of dissolving of ice at ambient water temperatures between 0 ◦ C and 4 ◦ C and salinity around 35 psu and the dependence on stratification (as characterizes many sites around Antarctica). In order to examine the process and scaling we use very strong stratification and vertical scales much less than those in the oceans. Figure 1: (a) The formation of doubl...
The effects of the slope of an ice–seawater interface on the mechanisms and rate of ablation of t... more The effects of the slope of an ice–seawater interface on the mechanisms and rate of ablation of the ice by natural convection are examined using turbulence-resolving simulations. Solutions are obtained for ice slopes $\unicode[STIX]{x1D703}=2^{\circ }{-}90^{\circ }$, at a fixed ambient salinity and temperature, chosen to represent common Antarctic ocean conditions. For laminar boundary layers the ablation rate decreases with height, whereas in the turbulent regime the ablation rate is found to be height independent. The simulated laminar ablation rates scale with $(\sin \unicode[STIX]{x1D703})^{1/4}$, whereas in the turbulent regime it follows a $(\sin \unicode[STIX]{x1D703})^{2/3}$ scaling, both consistent with the theoretical predictions developed here. The reduction in the ablation rate with shallower slopes arises as a result of the development of stable density stratification beneath the ice face, which reduces turbulent buoyancy fluxes to the ice. The turbulent kinetic energy ...
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