Geodetic mass balance of Mýrdalsjökull ice cap, 1999--2021

• Published in: Jökull
• Main Authors: Bernat, Maud, Belart, Joaquín, Berthier, Etienne, Jóhannesson, Tómas, Hugonnet, Romain, Dehecq, Amaury, Magnússon, Eyjólfur, Gunnarsson, Andri
• Other Authors: Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS), University of Washington Seattle, 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)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Observatoire des Sciences de l'Univers de Grenoble (Fédération OSUG)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP), Université Grenoble Alpes (UGA)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology; Langjökull; Mýrdalsjökull; Vatnajökull; Hofsjökull; Ice cap
• Online Access: https://hal.science/hal-04576056; https://doi.org/10.33799/jokull2023.73.035

International audience The mass balance of Mýrdalsjökull, the fourth largest Icelandic ice cap (520 km2 in 2019), has received less attention so far than the mass balance of the three largest ice caps, Vatnajökull, Hofsjökull and Langjökull. Here, we used digital elevation models (DEMs) derived from the untapped SPOT5 archive (2003−2014), lidar data (2010), Pléiades imagery (2014−2021), aerial photographs from 1999 and the ArcticDEM dataset (2010−2018) to estimate the mass balance of Mýrdalsjökull. A pre-processing of the DEMs was first performed: co-registration, filtering and void interpolation. Then, applying a Gaussian Process (GP) regression, a spatially and temporally continuous elevation dataset was created, in 15×15 m resolution and 30-day increments over the time span 1999 to 2021. Volume and mass changes based on the GP-interpolated elevation dataset were computed and analysed in 5- to 6-year intervals between 1999 and 2021. An average mass balance of −1.23 ± 0.10 m w.e. a−1 was estimated for this time period, with a trend towards a less negative mass balance from −1.83 ± 0.13 m w.e. a−1 (1999−2005) to −0.41 ± 0.03 m w.e. a−1 (2016−2021). An analysis of three climatically different catchments of Mýrdalsjökull showed a significant spatial variability in the estimated mass balance but a similar temporal variation