Initial results from a Bayesian calibration of a 3D glacial systems model for Antarctic deglaciation
Abstract
Past 3D deglaciation models for Antarctica have generally relied either on the application of geophysical inversion techniques that lack glaciological self-consistency, or on a small number of simulations using hand-tuned and poorly constrained glaciological models. In this context and following similar work for the Eurasian and North American ice-sheets, we present initial results from an ongoing Bayesian calibration of a Glacial Systems Model. The calibration is against a diverse set of paleo observations for relative sea level, ice extent and surface elevations, along with the present day ice-sheet configuration. The 3-D ice model includes a hybrid coupling of sheet/stream/shelf flow, sub-grid grounding-line flux parameterization, and visco-elastic bedrock response. The glacial systems model has about twenty ensemble parameters to capture uncertainties in glacial cycle climate, mass-balance processes, and ice dynamics. The Bayesian calibration provides a posterior distribution for these model parameters and thereby modelled glacial histories given the observational data sets. Thus meaningful error bars can be generated. Key regions in need of further constraint are also identified.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.C43A0489B
- Keywords:
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- 0726 CRYOSPHERE / Ice sheets;
- 0798 CRYOSPHERE / Modeling;
- 1621 GLOBAL CHANGE / Cryospheric change;
- 1641 GLOBAL CHANGE / Sea level change