Twenty-first century glacial and hydrological change in the Virkisjökull Glacier Observatory, Iceland

• Main Author: Mackay, Jonathan D
• Other Authors: Barrand, Nick, Hannah, David M., Krause, Stefan, Jackson, Chris, Everest, Jez, Aðalgeirsdóttir, Guðfinna, nerc
• Format: Thesis
• Language: English
• Published: 2020
• Subjects: GB Physical geography; GE Environmental Sciences; glacier; Iceland
• Online Access: http://etheses.bham.ac.uk//id/eprint/10059/7.hassmallThumbnailVersion/Mackay2020PhD.pdf; http://etheses.bham.ac.uk//id/eprint/10059/; http://etheses.bham.ac.uk//id/eprint/10059/7/Mackay2020PhD.pdf

This thesis uses climate, glacio-hydrological models (GHMs) and groundwater models to advance understanding of: 1) twenty-first century climate change impacts on glacier-fed river flow regime and proglacial groundwater dynamics at the Virkisjökull Glacier Observatory in Iceland; and 2) uncertainties associated with model projections which underpin this understanding. The research is split into three studies. Study 1 tests a novel, signature-based Limits of Acceptability framework for constraining structural uncertainties in GHMs. The framework successfully identifies deficiencies in different melt and runoff-routing model structures, but cannot identify a population of acceptable model structures. Study 2 uses an ensemble of regional climate projections and GHMs to project changes in 25 characteristics (signatures) of river flow regime up to 2100. The results show that the magnitude, timing and variability of river flow are sensitive to climate change and that projection uncertainties stem from incomplete knowledge of future climate and glacio-hydrological processes. The dominant uncertainty source, however, is signature-specific. Study 3 includes a proglacial groundwater model into the climate-GHM model chain and shows that climate change will perturb intra-annual groundwater level timing and variability leading to changes in groundwater-surface water interactions. Uncertainties in groundwater projections primarily stem from future climate uncertainty.