An exploratory modelling study of perennial firn aquifers in the Antarctic Peninsula for the period 1979–2016

• Published in: The Cryosphere
• Main Authors: J. M. van Wessem, C. R. Steger, N. Wever, M. R. van den Broeke
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2021
• Subjects: Environmental sciences; GE1-350; Geology; QE1-996.5; Antarctic; The Antarctic; Svalbard; Antarctic Peninsula; Greenland; Antarc*; The Cryosphere
• Online Access: https://doi.org/10.5194/tc-15-695-2021; https://doaj.org/article/6560505082334d6a9d869d17b49e1e4f

In this study, we focus on the model detection in the Antarctic Peninsula (AP) of so-called perennial firn aquifers (PFAs) that are widespread in Greenland and Svalbard and are formed when surface meltwater percolates into the firn pack in summer, which is then buried by snowfall and does not refreeze during the following winter. We use two snow models, the Institute for Marine and Atmospheric Research Utrecht Firn Densification Model (IMAU-FDM) and SNOWPACK, and force these (partly) with mass and energy fluxes from the Regional Atmospheric Climate MOdel (RACMO2.3p2) to construct a 1979–2016 climatology of AP firn density, temperature, and liquid water content. An evaluation using 75 snow temperature observations at 10 m depth and density profiles from 11 firn cores shows that output of both snow models is sufficiently realistic to warrant further analysis of firn characteristics. The models give comparable results: in 941 model grid points in either model, covering ∼28 000 km 2 , PFAs existed for at least 1 year in the simulated period, most notably in the western AP. At these locations, surface meltwater production typically exceeds 200 <math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow class="unit"><mi mathvariant="normal">mm</mi><mspace width="0.125em" linebreak="nobreak"/><mi mathvariant="normal">w</mi><mo>.</mo><mi mathvariant="normal">e</mi><mo>.</mo><mspace linebreak="nobreak" width="0.125em"/><msup><mi mathvariant="normal">yr</mi><mrow><mo>-</mo><mn mathvariant="normal">1</mn></mrow></msup></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="61pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="ff6da8763e65c65d71b7ee9dba2d73a5"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-15-695-2021-ie00001.svg" width="61pt" height="15pt" ...