1,2,1,2,1,1,1,1,1,1,1,2- 1Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Potsdam, Germany
- 2Institute of Geosciences, University of Potsdam, Potsdam, Germany
- 3Department of Earth Sciences, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- 4Department of Space Research and Technology, Technical University of Denmark, Lyngby, Denmark
- 5Institute of Northern Engineering, University of Alaska Fairbanks (UAF), Fairbanks, Alaska, USA
- 6Department of Environmental and Biological Sciences, Faculty of Science, Forestry and Technology, University of Eastern Finland (UEF), Kuopio, Finland
- 7Department of Agroecology, Land-CRAFT, Aarhus University, Denmark
- 8International Arctic Research Center, University of Alaska Fairbanks, Fairbanks, Alaska, USA
- 9Remote Sensing and Geoinformatics, GFZ Helmholtz Centre for Geosciences, Telegrafenberg, Potsdam, Germany
- 10Microwaves and Radar Institute, German Aerospace Center (DLR) e.V., Wessling, Germany
- 11Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zürich, Zürich, Switzerland
Thermo-erosional gullies are widespread landscape components in ice-rich Arctic permafrost regions. With accelerated climate warming and permafrost thaw, these gully networks are expected to expand. This not only accelerates in-situ ground-ice loss but also rearranges drainage pathways, which can have far-reaching consequences, modifying local hydrology as well as sediment, nutrient, carbon, and contaminant fluxes and impacting ecosystems at catchment scale.
The evolution of thermo-erosional gully systems following initiation is dynamic and likely influenced by incision-dependent snowdrift and moisture redistribution that affect the thermal conditions. To investigate the role of these factors and their consequences for the permafrost state within the gully and the surrounding uplands, we set up a simplified thermo-erosional gully model using the permafrost model CryoGridLite, including conductive heat transfer, soil water phase change, a dynamic snow scheme and simplified water redistribution. The model was parameterised and validated to represent two contrasting gully sites in western Alaska, using field data. The first site on the Baldwin Peninsula (BAP-B) represents a deeply incised coastal gully, while the second site on the Seward Peninsula (CSP-F) represents a shallow gully connected to a drained thermokarst pond basin. The data included topographical measurements with drone-based measurements of terrain elevation and DGPS measurements of elevation transects for the morphological setup and snow depth measurements along cross-gully transects to constrain asymmetric snowdrift. For additional parametrisation and validation, we used various in-situ measurements, including temperature depth-profiles and thaw depth from several field campaigns (2022 to 2025), as well as continuously measured temperatures along gully cross-transects (upland, slope gully base) at different depths (surface, 0.2 to 0.3m, and 1 m). Based on the validated model setups for both sites, we modified morphology and snowdrift constraints to compare temperature dynamics and permafrost state along the gully cross section under different setup scenarios.
Our modelling scenarios highlighted the importance of snowdrift for talik formation within the gully. Furthermore, the model simulations suggest increased seasonal thaw depths on the slopes, which may result in enhanced mass wasting and erosion-driven gully widening and, together with directional snowdrift, lead to asymmetric gully development. Finally, we conclude that such storyline simulations can provide valuable insights into potential future development trajectories under climate change and address open questions such as the role of thermo-erosional gullies in permafrost landscapes. This includes whether gullies stabilise upland permafrost through improved drainage or whether related topographical changes enhance snow accumulation, thereby accelerating permafrost degradation.
How to cite: Inauen, C., Langer, M., Ohl, S., Veremeeva, A., Morgenstern, A., Rettelbach, T., Ghosh, S., Opel, T., Palacin-Lizarbe, C., Seemann, F., Barth, S., Baysinger, M., Hanna, C., Luebker, T., Runge, A., Nitze, I., Hajnsek, I., and Grosse, G.: Setting up and parametrising a thermo-erosional gully model to study the impact of morphology and snowdrift on development trajectories, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21908, https://doi.org/10.5194/egusphere-egu26-21908, 2026.
