HR: 1340h
AN: H33C-0488    [Abstracts]
TI: A Statistical Approach to Estimating the Contribution of Glaciers to Future Sea-level Rise.
AU: * Death, R M
EM: ros.death@bristol.ac.uk
AF: Bristol Glaciology Centre, School of Geographical Sciences University Road,, Bristol, BS8 1SS United Kingdom
AU: Payne, A J
EM: A.J.Payne@bristol.ac.uk
AF: Bristol Glaciology Centre, School of Geographical Sciences University Road,, Bristol, BS8 1SS United Kingdom
AU: Gregory, J M
EM: j.m.gregory@reading.ac.uk
AF: University of Reading, Department of Meteorology University of Reading, Whiteknights, PO Box 217, Reading, RG6 6AH United Kingdom
AU: Hall, J W
EM: jim.hall@bristol.ac.uk
AF: University of Bristol, Department of Civil Engineering, University of Bristol, Queen's Building, University Walk , Bristol, BS8 1TR United Kingdom AU: Oerlemans, J
EM: j.oerlemans@phys.uu.nl
AF: Utrecht University, Institute for Marine and Atmospheric Research, Princetonplein 5, Utrecht, 3584 CC Netherlands
AB: Valley glaciers and small ice caps are expected to supply the bulk of the cryosphere's contribution to anthropogenic sea-level rise over the coming century (~ 0.23 m (IPCC, 2001)). The estimation of this contribution is hampered by the lack of quantitative data for the vast majority of glaciers worldwide (only 100 glaciers out of over160,000 present have mass-balance records for longer than 5 years). The issues surrounding the parameterisation of subgrid scale processes, uncertainties in parameter values and the propagation of errors in model prediction of sea-level rise are similar to those experienced in the prediction of discharge from ungauged river basins. Given the similarities between valley glacier systems and their hydrological counterparts, it maybe appropriate to use the techniques developed for hydrological modelling. Therefore, to calculate sea-level rise with an associated error we propose the following four stage procedure. First, a generic valley-glacier system model that allows for variations in width, depth, accumulation and ablation along the glacier is developed. Second, the model is calibrated against the small number of glaciers on which we have sufficient data. Third, a response surface of sea-level contribution as a function of glacier climatology and topography is constructed. Entailed in this stage is a rigorous assessment of the uncertainty propagated through the model due to uncertainties inherent in the input parameters. The final fourth stage is then to sample the response function, in accordance with estimates of the global distribution of glaciers in the climate-topography phase space, in order to estimate sea-level rise with a meaningful estimation of error. The use of methods traditionally employed by the hydrological community to a different study area highlights issues that contribute to an understanding of the limitations in defining variability within a system and quantifying uncertainty.
DE: 1827 Glaciology (1863)
DE: 1833 Hydroclimatology
DE: 1854 Precipitation (3354)
DE: 1860 Runoff and streamflow
DE: 1869 Stochastic processes
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting