Arbeitsbericht NAB 14-23

Sensitivity of modelled erosion rates to hydrologic transients and process representation in a hydraulicallycoupled ice-flow model

This report summarizes the research accomplished since the beginning of the project in January 2013. Most of the results obtained are summarized in a manuscript that was submitted to the international peer-reviewed journal Geomorphology on 14 November 2013. The final submitted manuscript forms the primary basis for this report and is appended below. To this we have added two appendices: Appendix A describes an alternative cavity-based description of the distributed drainage system and its implications for the erosion modelling summarized in the manuscript, and Appendix B brief summarizes a strategy that we had devised to obtain some insight into the implications of our seasonal-scale results for long-term simulations of glacial erosion. Based on our discussions with Urs Fischer and Wilfred Haeberli at the final project meeting in San Francisco on 11 December 2013, it was decided that we should turn our attention to the next phase of model development, rather than pursue long-term simulations with the existing model. Appendix A therefore represents the bulk of what has been accomplished since the time of submission of the interim report. Table 1 summarizes the project tasks accomplished and where in this report the results can be found. In addition to the research conducted since the interim report, Flavien Beaud has also presented this Nagra-funded work in two oral presentations: at the Annual Meeting of the Northwest Glaciologists (Vancouver, Canada, October 2013) and at the Fall Meeting of the American Geophysical Union (San Francisco, USA, December 2013).