Constraining Subglacial Plume Integral Model Parameters Using Stereoscopic PIV and planar LIF Experiments*

Subglacial plume modeling is an important part in the simulations of melting glaciers, ice sheet dynamics, and ocean circulations in the poles. Because of the large disparity in spatio-temporal scales, full 3D modeling of subglacial plumes within an ocean circulation model is prohibitively costly. Instead, the plumes are incorporated into circulation models using the integral approach that is 1D and predicts the mean properties of a subglacial plume as it rises along a water-ice interface. With proper coupling between a plume integral model and a circulation model, realistic simulations of the freshwater flux from melted ice into ocean can be achieved. In this talk, we focus on testing and validating the integral model formulations and parameters of a single subglacial plume rising along a vertical ice face. We achieved this by analyzing detailed fluid velocity and passive tracer measurements of a laboratory subglacial plume. Specifically, we did stereoscopic particle image velocimetry (PIV) and planar laser-induced fluorescence (LIF) experiments at different plume cross-sections along the plume trajectory, and this allowed us to quantify the turbulent transport of momentum, mass, and heat close to the water-ice face. We also did matched experiments on a non-melting, solid wall to provide a baseline for comparison.