The application and modification of WRF-Hydro/Glacier to a cold-based Antarctic glacier

• Main Authors: Pletzer, Tamara, Conway, Jonathan P., Cullen, Nicolas J., Eidhammer, Trude, Katurji, Marwan
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2023
• Subjects: article; Verlagsveröffentlichung; Antarctic; Commonwealth Glacier; McMurdo Dry Valleys; Antarc*; polar desert
• Online Access: https://doi.org/10.5194/egusphere-2023-835; https://noa.gwlb.de/receive/cop_mods_00066591; https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00065072/egusphere-2023-835.pdf; https://egusphere.copernicus.org/preprints/2023/egusphere-2023-835/egusphere-2023-835.pdf

The McMurdo Dry Valleys (MDV) are home to a unique microbial ecosystem dependent on the availability of freshwater. It is a polar desert and freshwater originates almost entirely from surface and near-surface melt of cold-based glaciers. Understanding the future evolution of these environments requires the simulation of the full chain of physical processes-from net radiative forcing, surface energy balance, melt, runoff and the transport of meltwater in stream channels from the glaciers to the terminal lakes where the microbial community resides. We present the first application of the WRF-Hydro/Glacier model in the MDV. The model was tested for a 7-month period (1 August 2021 to 28 February 2022) at a point on Commonwealth Glacier and forced by automatic weather station observations. We found it was necessary to limit the percolation of meltwater through ice layers to represent near-surface runoff as observed in the field. We also tuned the parameters controlling the spectral albedo for snow and ice based on observations to model the evolution of broadband albedo over a melt season. With these modifications, we were able to accurately simulate surface and near-surface temperatures, surface height change, broadband albedo and runoff over a melt season. These modifications show that once the model is adapted to this extreme environment, the model is capable of accurately capturing the physical processes governing the meltwater generation of an MDV glacier. This will enable future efforts to model spatially distributed melt and streamflow in the MDV and will allow us to answer questions around the timing of meltwater transport and the present and future hydrological response of melt to atmospheric forcing.