An Adaptive Mesh Refinement (AMR) Subglacial Hydrology Model

Abstract:

Observations suggest that the water flow under ice sheets and glaciers can have a strong influence on ice dynamics, particularly through changes in basal water pressure. A comprehensive ice-sheet model should include the effect of basal hydrology, but very often its effects are neglected or very crudely approximated. Subglacial hydrology is challenging in part due to the wide separation of spatial and temporal scales between the glacier and the typical subglacial water channel, and also the widely varying spatial scales of the subglacial system itself. To tackle this, we have developed an Adaptive Mesh Refinement (AMR) model based on the Chombo library. Building on the model proposed by Sommers et al., the present model naturally transitions from distributed water drainage to channelized flow, adding fine mesh resolution where needed to accurately capture the local degree of channelization, a key component of the coupling between the ice sheet and the subglacial motion. We present examples demonstrating the effectiveness of our approach.