A new free drift sea ice velocity dataset for improved representations of ice drift trajectories

Student Seminar Series

Department of Atmospheric & Oceanic Sciences

presents

a talk by

Charles Brunette
PhD student

A new free drift sea ice velocity dataset for improved representations of ice drift trajectories

Previous work shows that tracking the motion of sea ice in a Lagrangian framework can be used to produce skillful seasonal forecasts of sea ice at the pan-Arctic scale (Williams et al. 2016) and at the regional scale (Brunette et al. 2019) and can also be used to analyze socio-environmental impacts related to sea ice circulation (Newton et al. 2017). However, the Polar Pathfinder sea ice motion dataset from the National Snow and Ice Data Centre (Tschudi et al. 2016), which is commonly used for calculations of ice drift trajectories, contains significant biases in drift speed and angle. The bias is especially strong in the summer when less satellite drift-vectors are available, and the Polar Pathfinder composite product relies more heavily on poorly-constrained free drift estimates (ice motion in response to wind forcing and ocean currents in the absence of internal stresses). To improve the quality of ice motion estimates in the summer, we propose to compile a new sea ice free drift dataset, based on surface winds from ERA-Interim and calibrated on drifting buoys from the International Arctic Buoy Program.

I will present recent work on the parameterization of an ice state dependent transfer coefficient between wind speed and sea ice speed, and estimates of the near surface oceanic currents that are necessary to constrain ice motion.

Wednesday Nov 20/ 2.30 PM/ Room 934 Burnside Hall