:The AAPP and IMAS (coordinated by AAPP Project 6: Sea Ice) are proud to host an onsite and online seminar by Dr Stefanie Arndt from the Alfred Wegener Institute on 23 August:
Variability of Antarctic Snow Properties and its Implications for Sea Ice Mass Budget
Snow cover on Antarctic sea ice significantly influences the sea ice mass and energy budgets through complex physical transition processes. This study presents in-situ observations of snowpack properties from numerous expeditions in the Weddell Sea since the 1990s, revealing significant seasonal and regional variations. High mean bulk densities in late summer and autumn, attributed to compacted wind slab and melt-freeze clusters, contrast with lower densities in winter due to depth hoar crystals. On seasonal sea ice, bulk densities exceeding 400 kg m-3 are observed in summer, but decreases below 300 kg m-3 due to freeze-thaw processes.
The additional analysis of 10 years of autonomous snow observations in the Weddell Sea shows that the highest snow accumulation rates (8 to 10 cm per month) occur between May and October, with snow ice formation contributing one third of the snowpack, mainly in the area of perennial sea ice.
These regional variations in snow bulk density and snow-to-ice conversion processes determine the effective heat conductivity, influence the thermodynamic ice growth and contribute to uncertainties in large-scale sea ice mass budgets from satellites and numerical models.
Dr. Stefanie Arndt is a sea ice physicist at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) in Bremerhaven. She recently established a Young Investigator Group on “Learning from local snow properties for large-scale Antarctic ice pack volume” (SNOWflAke) at both AWI and the University of Hamburg.
In her scientific career, Stefanie Arndt focuses on the seasonal cycle of surface properties of Arctic and Antarctic sea ice and their impact on the energy and mass budgets of the ice-covered oceans. Over the years, she has participated in a total of eleven ship-based and three land-based expeditions, and has led the sea ice and snow team on-site multiple times. Notably, she led the international sea ice team for five months during the largest Arctic expedition of our time, the “Multidisciplinary drifting Observatory for the Study of Arctic Climate” (MOSAiC).
In addition to her research, Stefanie Arndt actively contributes to the scientific community by being a member of leading committees in several international working groups, such as "Antarctic Sea Ice Processes and Climate" (ASPeCt) and the "SOOS regional Working Group Weddell Sea and Dronning Maud Land" (SOOS WS-DML).