Modeling Active Layer Depth of Permafrost under Changing Surface Boundary Conditions

A new approach is developed for modeling the active layer depth of permafrost under changing boundary conditions without assuming linear temperature profile, which is often assumed in solving the traditional Stefan problems. Time-varying ground heat flux is obtained from net radiation and surface temperature using the Maximum Entropy Production (MEP) model as the driver of the melting process. Conductive heat flux at the melting front is approximated in terms of an analytical function of ground heat flux. The simulated active layer depth is in good agreement with the field observations. Surface energy budget according to the MEP model is also in close agreement with field observations.