The Impact of Tides on Simulated Landfast Ice in a Pan-Arctic Ice-Ocean Model

Abstract

The impact of tides on the simulated landfast ice cover is investigated. Pan-Arctic simulations are conducted with an ice-ocean (CICE-NEMO) model with a modified rheology and a grounding scheme. The reference experiment (without tides) indicates there is an overestimation of the extent of landfast ice in regions of strong tides such as the Gulf of Boothia, Prince Regent Inlet, and Lancaster Sound. The addition of tides in the simulation clearly leads to a decrease of the extent of landfast ice in some tidally active regions. This numerical experiment with tides is more in line with observations of landfast ice in all the regions studied. Thermodynamics and changes in grounding cannot explain the lower landfast ice area when tidal forcing is included. We rather demonstrate that this decrease in the landfast ice extent is dynamically driven by the increase of the ocean-ice stress due to the tides.