Spatiotemporal variation in the specific surface area of surface snow measured along the traverse route from the coast to Dome Fuji, Antarctica

• Main Authors: Inoue, Ryo, Aoki, Teruo, Fujita, Shuji, Tsutaki, Shun, Motoyama, Hideaki, Nakazawa, Fumio, Kawamura, Kenji
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2024
• Subjects: article; Verlagsveröffentlichung; Antarc*; Antarctic; Antarctica; East Antarctica; Ice Sheet
• Online Access: https://doi.org/10.5194/egusphere-2024-769; https://noa.gwlb.de/receive/cop_mods_00072498; https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00070708/egusphere-2024-769.pdf; https://egusphere.copernicus.org/preprints/2024/egusphere-2024-769/egusphere-2024-769.pdf

To better understand the surface properties of the Antarctic ice sheet, we measured the specific surface area (SSA) of surface snow during two round-trip traverses between a coastal base near Syowa Station, located 15 km inland from the nearest coast, and Dome Fuji, located 1066 km inland, in East Antarctica from November 2021 to January 2022. Using a handheld integrating sphere snow grain sizer (HISSGraS), which directly measures snow surface without sampling, we collected 215 sets of SSA data, each set comprising measurements from 10 surfaces along a 20 m transect. The measured SSA shows no elevation or temperature dependence between 15 and 500 km from the coast (elevation: 615–3000 m), with a mean and standard deviation of 25 ± 9 m2 kg−1. Beyond this range, SSA increases toward the interior, reaching 45 ± 11 m2 kg−1 between 800 and 1066 km from the coast (3600–3800 m). SSA shows significant variability depending on surface morphologies and short-term meteorological events. For example, (i) glazed surfaces formed by an accumulation hiatus in katabatic wind areas show low SSA (19 ± 4 m2 kg−1), decreasing the mean SSA and increasing SSA variability. (ii) Freshly deposited snow shows high SSA (60–110 m2 kg−1), but the snow deposition is inhibited by snow drifting at wind speeds above 5 m s−1. Our analyses clarified that temperature-dependent snow metamorphism, snowfall frequency, and wind-driven inhibition of snow deposition play crucial roles in the spatial variation of surface snow SSA in the Antarctic inland. The extensive dataset will enable the validation of satellite-derived and model-simulated SSA variations across Antarctica.