The InterFrost benchmark of Thermo-Hydraulic codes for cold regions hydrology – first inter-comparison phase results

• Main Authors: Grenier, Christophe, Rühaak, Wolfram
• Other Authors: Biologie Neurovasculaire et Mitochondriale Intégrée (BNMI), Université d'Angers (UA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Technische Universität Darmstadt - Technical University of Darmstadt (TU Darmstadt), Department of Geothermal Science and Technology, Institute of Applied Geosciences Darmstadt (IAG), Darmstadt University of Technology Darmstadt -Darmstadt University of Technology Darmstadt, EGU, InterFrost Team
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2016
• Subjects: [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; [SDE]Environmental Sciences; [SDE.MCG]Environmental Sciences/Global Changes; Canada; permafrost
• Online Access: https://hal.archives-ouvertes.fr/hal-01396563; https://hal.archives-ouvertes.fr/hal-01396563/document; https://hal.archives-ouvertes.fr/hal-01396563/file/EGU2016-11310.pdf

Interfrost Team International audience Climate change impacts in permafrost regions have received considerable attention recently due to the pronounced warming trends experienced in recent decades and which have been projected into the future. Large portions of these permafrost regions are characterized by surface water bodies (lakes, rivers) that interact with the surrounding permafrost often generating taliks (unfrozen zones) within the permafrost that allow for hydrologic interactions between the surface water bodies and underlying aquifers and thus influence the hydrologic response of a landscape to climate change. Recent field studies and modeling exercises indicate that a fully coupled 2D or 3D Thermo-Hydraulic (TH) approach is required to understand and model past and future evolution such units (Kurylyk et al. 2014). However, there is presently a paucity of 3D numerical studies of permafrost thaw and associated hydrological changes, which can be partly attributed to the difficulty in verifying multi-dimensional results produced by numerical models. A benchmark exercise was initialized at the end of 2014. Participants convened from USA, Canada, Eu-rope, representing 13 simulation codes. The benchmark exercises consist of several test cases inspired by existing literature (e.g. McKenzie et al., 2007) as well as new ones (Kurylyk et al. 2014; Grenier et al. in prep.; Rühaak et al. 2015). They range from simpler, purely thermal 1D cases to more complex, coupled 2D TH cases (benchmarks TH1, TH2, and TH3). Some experimental cases conducted in a cold room complement the validation approach. A web site hosted by LSCE (Laboratoire des Sciences du Climat et de l'Environnement) is an interaction platform for the participants and hosts the test case databases at the following address: https://wiki.lsce.ipsl.fr/interfrost. The results of the first stage of the benchmark exercise will be presented. We will mainly focus on the inter-comparison of participant results for the coupled cases TH2 & TH3. Both cases ...