PISM models the Antarctic contribution to meltwater pulse 1A

Published: Oct 8, 2014 by The PISM Authors

In a new Nature Communications paper, researchers at Victoria University and the University of New South Wales describe a model study of Antarctic ice sheet evolution over the last 25 kyr using PISM with ocean-forcing inputs from the Earth system model LOVECLIM. They show that when the ocean around Antarctica becomes more stratified, warm water at depth melts the ice sheet faster than when the ocean is less stratified.

Figure from Golledge et al, 2014

The study used a large ensemble of 15 km PISM simulations in a data-constrained mode. In the simulations that best fit a variety of temporal and spatial observations, several episodes of accelerated ice-sheet recession occurred, with the timing of the largest being coincident with meltwater pulse 1A. This episode saw an abrupt rise in global sea level, with an Antarctic contribution of nearly three meters over just a few centuries.

Both this blog entry and this Science Daily news item summarize the work and relate the modeled melt from 14,000 years ago to present-day Antarctic conditions.

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.