Liquid Water Flow and Retention on the Greenland Ice Sheet in the Regional Climate Model HIRHAM5: Local and Large-Scale Impacts
Published in Frontiers in Earth Science, 2017
This study present an update of the HIRHAM5 regional climate model. We improved the subsurface scheme of the model to include snow densification, varying hydraulic conductivity, irreducible water saturation, and a parametrization of Darcy flow to simulate liquid water percolation and retention in the Greenland Ice Sheet firn. It tests the impact of these developments through sensitivity experiments and compares model outputs with ice core, remotely sensed surface melt and PROMICE observations.
The results show that the improved model realistically captures surface mass balance patterns, melt day variability, and subsurface temperature structures. The choice of albedo scheme strongly influences surface meltwater production and subsequent infiltration, while the irreducible water saturation parameterization affects the formation of firn aquifers and perched ice layers. Overall, the enhancements improve model performance, particularly for simulating Greenland-wide runoff and subsurface hydrology.
Recommended citation:
Langen P., Fausto R., Vandecrux B., Mottram R., Box J.: "Liquid Water Flow and Retention on the Greenland Ice Sheet in the Regional Climate Model HIRHAM5: Local and Large-Scale Impacts." Frontiers in Earth Science, http://doi.org/10.3389/feart.2016.00110, 2017.