Spatial scales of seasonal snow property variations on Antarctic sea ice
Snow on sea ice alters the properties of the underlying ice cover as well as associated exchange processes at the interfaces between atmosphere, sea ice, and ocean. As Antarctic snow cover persists during most of the year, it contributes significantly to the sea-ice mass and energy budgets due to comprehensive physical (seasonal) transition processes within the snowpack. However, field studies reveal not only a strong seasonality but especially spatial variations from local to regional scales. It is therefore necessary to quantify seasonal snow processes, such as internal snowmelt, snow metamorphism, and snow-ice formation at multiple spatial scales on Antarctic sea ice. Doing so, we present here in-situ observations of physical snow properties from point measurements (snow pits) and transect lines (SnowMicroPen, SMP) during recent expeditions in the Weddell Sea from 2013 to 2019, covering summer and winter conditions. Results from a case study of snow pit analyses in the Weddell Sea during austral winter reveal a high spatiotemporal variability of snow parameters highlighting the need to distinguish between seasonal and perennial snow regimes. Also, it is shown that snow grain size dominates the spatial variability of the snowpack while snow density variability can be neglected. In order to extend local snow pit analysis towards the description of snow layer evolution on small scales (up to 500 meters), SMP measurements are added. An applied layer tracking algorithm to the vertical density profiles throughout the snowpack allows to quantify length-scale variabilities of snow properties in different ice regimes. Overall, results will improve our understanding of seasonal processes in the snowpack and will guide us towards upscaling approaches of vertical snow layers on Antarctic sea ice.
PS > 111
PS > 118