The Parallel Ice Sheet Model pism0.7 is an open source, parallel, high-resolution ice sheet model. Features:
|Combustion of available fossil fuel resources sufficient to eliminate the Antarctic Ice Sheet|
|investigator:||R. Winkelmann and others|
Ice sheet scientists have probably asked each other, over a beer or otherwise, how much of the Antarctic Ice Sheet would melt if all fossil fuels were burned up until they were gone. Co-author Ken Caldeira of this paper said in an interview that “I've been wondering about this question for 35 years but was never able to address it.” These authors think that ice sheet science has gotten sophisticated enough to take this question seriously.
Their PISM-based answer is that serious destruction of the ice sheet occurs in the first millenium, at about 3 m sea level rise per century. Actually, PISM is at the end of a chain of models: emission scenarios, CO2 concentrations, and global mean temperature pathways are first combined in an Earth system model (GENIE) and then downscaled to surface and ocean temperature anomalies for Antarctica using scaling factors also from Earth system modeling (ECHAM5/MPIOM). These regional warming scenarios are then used to force PISM. In particular, PISM's positive-degree-day scheme models surface melt and a three-equation model (BRIOS model; Timmerman et al. 2002) describes subshelf melting.
Losses come from a combination of marine-ice-sheet instability and surface elevation versus mass balance feedback. However, in the first century the simulations show the same relatively-modest AIS mass changes as seen in other recent (e.g. IPCC AR5) modeling work, because dynamic losses driven by increasing ocean temperatures are partly offset by increasing snowfall.
As a result of the buzz around Winkelmann et al. (2015)'s modeling of the effect of full conversion of available fossil fuels in the ground into atmospheric CO2, using PISM for determining ice dynamics/response timescale, on 5 October our local paper the Fairbanks Daily News Miner featured PISM. The content is a bit warped by scientist-to-journalist transmission issues, but we are happy to have local recognition of this UAF-lead project!
See the official position announcement here.
We are looking for a candidate who is interested in taking part in the research project “Modelling the ice flow in the western Alps during the last glacial cycle” which is a joint initiative between ETH Zurich and the University of Bern (Prof. Christoph Raible and Dr. Juan Jose Gomez-Navarro). The objective is to better understand the chronology of the last glaciation over the Alps via a modelling approach. The core of this doctoral research will be to model the ice flow and the glacial extent in the western Alps during the last glacial cycle. For that purpose, the PhD student will set up and run the Parallel Ice Sheet Model (PISM) on the clusters of the Swiss National Supercomputing Centre. The crucial step in setting up in PISM will be to include high-resolution climate simulation results, which will be conducted at the University of Bern. The combination of the two state-of-the-art models (ice flow and climate) will give a new insight of the ice flow field prevailing in the western Alpine region during some periods of interest like the last glacial maximum (22000 BP) and an earlier period (65000 BP). The final goal of the PhD will be to compare the new model results to the geomorphological evidence left on the Swiss landscape during the last glacial cycle (e.g. moraines, erratic boulders) in collaboration with quaternary geologists of EHT Zurich. The PhD student will be supervised by Dr. Guillaume Jouvet and Prof. Martin Funk.
The ideal candidate has a master degree either in geophysics, earth sciences, physics, applied mathematics, computer science, or a related field, and a keen interest in modelling of geophysical processes. Previous experience in computer modelling and scientific programming languages (C/C++, Python, Matlab) is an asset. Good writing and communication skills as well as the motivation to fruitfully collaborate within an interdisciplinary framework are essential, in particular with our climate modelling partners at the University of Bern.
For additional information please refer to www.glaciology.ethz.ch or contact Dr. Guillaume Jouvet, email@example.com (no applications).
A new open-access paper by Ricarda Winkelmann and others uses PISM to address an admittedly extreme question: If all currently-attainable fossil fuel resources are converted to atmospheric greenhouse gases, what happens to the Antarctic Ice Sheet?
This paper's model-based answer is that serious destruction of the ice sheet occurs in the first millenium, at about 3 m sea level rise per century. Such a large mass loss rate tails off in the two following millenia. The large losses come from a combination of marine-ice-sheet instability and surface elevation versus mass balance feedback, both of which are modeled effects in PISM. However, in the first century of the simulations there are the same relatively-modest AIS mass changes as seen in other recent modeling work, because dynamic losses driven by increasing ocean temperatures are partly offset by increasing snowfall.
Here is a quick methods summary, with more detail found in the paper and its supplementary material: Emission scenarios, CO2 concentrations, and global mean temperature pathways are combined in an Earth system model and then downscaled to surface and ocean temperature anomalies for Antarctica. These regional warming scenarios are then used to force PISM, in particular using its positive-degree-day scheme to model surface melt and a three-equation model for subshelf melting.
US National Public Radio featured the paper, including comments by co-author Ken Caldeira, on the 11 September edition of All Things Considered, as did the New York Times.
This is a re-posting of the CRYOLIST announcement from Uwe Mikolajewicz
The Max Planck Institute for Meteorology (MPI-M) is a multidisciplinary center for climate and Earth system research located in Hamburg, Germany. MPI-M contributes to the BMBF project “From the Last Interglacial to the Anthropocene: Modeling a Complete Glacial Cycle” (PalMod), which aims at simulating the climate from the peak of the last interglacial up to the present using comprehensive Earth System Models.
With respect to this research project, we have an open position for a
The successful candidate will be part of a local team performing and analyzing transient simulations from the last Glacial to the Holocene with an interactively coupled atmosphere-ocean-ice sheet model. Additionally the candidate will contribute to the development of this model. The model system will consist of the MPI-Earth system model and the ice sheet model PISM.
For information on PhD Fellowships in Earth System Modeling at MPI-M, see
PISM is jointly developed at the University of Alaska, Fairbanks (UAF) and the Potsdam Institute for Climate Impact Research (PIK). For more about the team see the UAF Developers and PIK Developers pages.
UAF developers, who are in the Glaciers Group at the GI, are supported by NASA's Modeling, Analysis, and Prediction and Cryospheric Sciences Programs (grants NAG5-11371, NNX09AJ38C, NNX13AM16G, NNX13AK27G) and by the Arctic Region Supercomputing Center.