Mass-conserving subglacial hydrology in the Parallel Ice Sheet Model v0.6

Published: Jun 1, 2015 by The PISM Authors

Thickness of subglacial water in "routing" model.

Thickness of subglacial water in “routing” model.


Title	Mass-conserving subglacial hydrology in the Parallel Ice Sheet Model v0.6
Authors	E. Bueler and W. van Pelt
Venue	Geoscientific Model Development

This paper describes and tests a major extension of PISM, introduced in v0.6 and fully-supported in v0.7, a two-horizontal-dimension subglacial hydrology model which combines till with a distributed system of water-filled, linked cavities. This sub-model accomplishes three specific goals: (1) conservation of the mass of water, (2) simulation of spatially- and temporally-variable basal shear stress from physical mechanisms based on a minimal number of free parameters, and (3) convergence under grid refinement. Besides a broad approach to the source of the model equations and detailed attention to the implementation and testing of the numerics, this paper demonstrates the model at scale by modeling the whole Greenland ice sheet at 2 km horizontal resolution, with one million nodes in the hydrology grid. But the model is far from complete. It both takes a very conservative approach to coupling hydrology to a model for basal shear, and it does not include the physics which determines the location and evolution of subglacial conduits.

A two-year PostDoc positions in ice sheet and Earth system modelling is available in the Ice Dynamics group, as part of the new Earth Resilience Science Unit (ERSU), at the Potsdam Institute for Climate Impact Research (PIK).

Two PhD fellowship positions in ice sheet modelling are advertised at the Niels Bohr Institute, University of Copenhagen.

The Alfred Wegener Institute, Bremerhaven, is offering a PhD position in the field of coupled ice sheet-ocean modelling. The core of the project is to run simulations with FESOM-PISM (a coupled ocean-ice shelf-ice sheet model with evolving cavity geometries) for different 21st-century climate projections to obtain well-constrained trajectories of future ice mass loss from the vast Antarctic Ice Sheet. Model results will feed into a fingerprinting method that considers the ocean response as well as gravitational effects and contributions from other sources. The final product will be a time series of global maps of regional sea-level variations that consider all of the most relevant processes.