A Consistent Framework for Coupling Basal Friction With Subglacial Hydrology on Hard‐Bedded Glaciers

• Published in: Geophysical Research Letters
• Main Authors: Gilbert, Adrien, Gimbert, Florent, Thøgersen, Kjetil, Schuler, Thomas, V, Kääb, Andreas
• Other Authors: Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), ANR-18-CE01-0015,SAUSSURE,Glissement des glaciers et pression hydrologique sous glaciaire en relat(2018)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: [SDE]Environmental Sciences; Paterson; Van Pelt; Ice Sheet
• Online Access: https://hal.science/hal-03852633; https://hal.science/hal-03852633/document; https://hal.science/hal-03852633/file/Gilbert2022.pdf; https://doi.org/10.1029/2021gl097507

International audience Flow variability of ice sheets and glaciers adds a large uncertainty to projections of their evolution and their future contribution to sea level rise (e.g., Mouginot et al., 2019; Ritz et al., 2015; Shepherd et al., 2019). Ice flow variability arises from the complex relationship between sliding speed, stress balance, water pressure, and temperature at the glacier base, all of which, in addition, depend on the properties of the substrate beneath the ice (Cuffey & Paterson, 2010). In particular, the difficulty in computing basal water pressure (e.g., Downs et al., 2018; Flowers, 2015) limits the predictive power of current ice sheet models (Ritz et al., 2015), and therefore the ability to project the future of the cryosphere under climate change. Two-way coupled models of ice flow and subglacial hydrology, in which sliding velocity has an effect on subglacial hydrology and vice-versa (e.g., Hewitt, 2013; Hoffman & Price, 2014; Pimentel et al., 2010), provide useful tools to test the sensitivity of ice dynamics to melt water supply. These models are also needed to evaluate the subglacial hydrology and friction theories by confronting modeled with observed ice velocities (Brinkerhoff et al., 2021). Ice flow and subglacial hydrology models are usually linked by a friction law that relates water pressure, basal shear stress, and sliding velocity, and an equation linking the sliding speed to the efficiency of the distributed drainage system (e.g., Bueler & van Pelt, 2015; Gagliardini & Werder, 2018; Hoffman & Price, 2014). The distributed subglacial drainage system under hard-bedded glaciers consists of a network of connected cavities (