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Completed research project

Title / Titel SuMo - Investigation of Subscale Modelling Approaches - a case study in mass balance modelling of ice sheets
PDF Abstract (PDF, 14 KB)
Summary / Zusammenfassung In the earth sciences models are increasingly being used to explore the past, replicate the present and predict the future at scales ranging from that of, for example, individual particles in models of snow saltation to tens of kilometers in General Circulation Models. As the importance of models in decision making, particularly with respect to future changes in climate increases, so too does the necessity to develop methodologies to combine models of differing widely scales whilst retaining information appropriate to individual processes. Although a wide range of research has investigated individual methods to combine models of differing scales, little systematic work has compared the sensitivity of model results to differing approaches and, importantly, quantified the resulting influence on model uncertainty.
The SuMo project undertakes a systematic exploration of a variety of methods for subscale modelling for the exemplar of ice sheet modelling. Ice sheet models often run at resolutions of 10-20km which, while appropriately resolving ice flow, are generally recognised to be insufficient for the representation of mass balance, particularly in terms of ice nucleation and narrow ablation zones. A set of methods either parametrically representing mass balance or implementing subscale models of mass balance are being implemented both over the entire model domain and at locations where subscale processes are thought to be most important. The implementation will be integrated into the GLIMMER community ice sheet model, thus giving a wide community of users access to the results and facilitating an investigation of the sensitivity of model results under a range of accepted test scenarios (the so-called EISMINT experiments).

The project will have three key outcomes:
1. A review of existing methods for modelling subscale information within numerical models
2. A set of refined mass balance modules implementing selective and non-selective subscale modelling approaches for the GLIMMER ice sheet model, improving the reliability of simulations of the impact of climate change on ice sheets
3. A detailed assessment of the uncertainty associated with ice sheet model simulations, originating from input topography, climate and model parameters
Publications / Publikationen Hebeler, F. & Purves, R.S., 2008:
Parameterisation of low resolution melt modelling using hypsometric subgrids and its susceptibility to uncertainty. Hydrological Processes, DOI 10.1002/hyp.7034

Weitere Informationen

Keywords / Suchbegriffe parameterisation, Ice sheet modelling, mass balance, melt modelling, subscale modelling, hypsometric subgrids, process modelling
Project leadership and contacts /
Projektleitung und Kontakte
Felix Hebeler (Project Leader)
Funding source(s) /
Unterstützt durch
Forschungskredit der Universität Zürich
Duration of Project / Projektdauer Mar 2008 to Mar 2009