Effects of meteorology and soil moisture on the spatio-temporal evolution of the depth hoar layer in the polar desert snowpack

• Published in: Journal of Glaciology
• Main Authors: Davesne, Gautier, Domine, Florent, Fortier, Daniel
• Other Authors: Takuvik Joint International Laboratory ULAVAL-CNRS, Centre National de la Recherche Scientifique (CNRS)-Université Laval Québec (ULaval)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: thermal conductivity; polar desert; soil moisture; depth hoar; Arctic snowpack; [SDE.MCG]Environmental Sciences/Global Changes; Arctic; Hunt Island; Resolute Bay; Ward Hunt Island; Journal of Glaciology; Tundra
• Online Access: https://hal.archives-ouvertes.fr/hal-03427894; https://hal.archives-ouvertes.fr/hal-03427894/document; https://hal.archives-ouvertes.fr/hal-03427894/file/135-DavesneJG2021.pdf; https://doi.org/10.1017/jog.2021.105

International audience In polar deserts, depth hoar (hereinafter: DH) growth is not systematic unlike on tundra and this is critical for snowpack properties. Here, we address the spatio-temporal variability of the DH layer in the polar desert at two sites in the Canadian High Arctic: Ward Hunt Island (83°N) and Resolute Bay (75°N). Our data show that, over humid areas, DH represented a larger fraction of the snowpack and was characterized by lower density and coarser crystals than over dry gravelly areas. Increased soil moisture extends the zero-curtain period during freeze-up, leading to stronger temperature gradients in the snowpack and greater kinetic metamorphism. Our results also demonstrate that the large inter-annual variability in DH is primarily driven by wind conditions in the fall since this key variable controls the initial snow density and snow onset date. These strong controls exerted by soil moisture and meteorological conditions on DH growth in polar deserts highlight the possibility of major changes in polar snowpacks physical properties in response to the rapid climate and environmental changes currently affecting these regions.