Katarzyna L P Warburton , Joanmarie Del Vecchio , Colin R. Meyer, Marisa C Palucis

On many frozen hillslopes, subsurface water above permafrost is routed through regularly spaced, linear features known as water tracks. We test whether water tracks form through thermal channelization, where heat from viscous dissipation in flowpaths deepens the active layer, creating a preferred flow path that attracts more water. We derive equations for suprapermafrost Darcy flow and, using linear stability analysis, we calculate growth rates and obtain wavelength selection for this system, which we compare to observed water track spacing from the high Arctic. Our model predictions are sensitive to flow speed, but the predicted cross-slope water track patterns are consistent with observed water track spacing under high flow conditions in the Low Arctic. Our model implies that signatures of changing climate might be found in changing water track spacing. However, feedback between flow and thaw is unlikely to drive flow path development in areas of low flow rate.