I’m excited to share that my paper has been accepted in JGR: Oceans. Learn about how Arctic sea ice geometry influences the transfer of momentum across the ice-ocean interface, and how well that’s described by current theories.

Comparing observations and parameterizations of ice-ocean drag through an annual cycle across the Beaufort Sea

We used observations from moorings to investigate ice-ocean drag over the course of a year and saw consistent seasonal signals with a minimum drag in the summer/fall.

Timeseries of ice-ocean drag measurements

Direct measurements of ice geometry allowed us to compare these results to parameterizations used in modern sea ice models (e.g, such as the one introduced for CICE). Together, the observations and model parameterizations showed that the seasonal signals that were tied to the growth and melt of ice keels; when the keels melted, the drag coefficients significantly decreased.

Overall, a positive outlook for the parameterizations we tested: they were able to predict the drag coefficients when the real ice geometry was used as input. BUT there were challenges in predicting geometry from bulk measures (especially floe sizes during melt season). This may explains the seasonal mismatch seen between past observations/model results.

Hopefully these results can be used to improve models of sea ice dynamics, and to better constrain the surface boundary conditions when looking at things like upper ocean shear-driven mixing.