Articles | Volume 10, issue 1
The Cryosphere, 10, 227–244, 2016
The Cryosphere, 10, 227–244, 2016

Research article 21 Jan 2016

Research article | 21 Jan 2016

An analytical model for wind-driven Arctic summer sea ice drift

H.-S. Park1 and A. L. Stewart2 H.-S. Park and A. L. Stewart
  • 1Korea Institute of Geoscience and Mineral Resources, Daejeon, South Korea
  • 2Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, USA

Abstract. The authors present an analytical model for wind-driven free drift of sea ice that allows for an arbitrary mixture of ice and open water. The model includes an ice–ocean boundary layer with an Ekman spiral, forced by transfers of wind-input momentum both through the sea ice and directly into the open water between the ice floes. The analytical tractability of this model allows efficient calculation of the ice velocity provided that the surface wind field is known and that the ocean geostrophic velocity is relatively weak. The model predicts that variations in the ice thickness or concentration should substantially modify the rotation of the velocity between the 10 m winds, the sea ice, and the ocean.

Compared to recent observational data from the first ice-tethered profiler with a velocity sensor (ITP-V), the model is able to capture the dependencies of the ice speed and the wind/ice/ocean turning angles on the wind speed. The model is used to derive responses to intensified southerlies on Arctic summer sea ice concentration, and the results are shown to compare closely with satellite observations.

Short summary
We have derived an analytical model for wind-driven free sea ice drift. We allow for partial sea ice cover using the "mixture layer" formulation and explicitly assume an oceanic Ekman layer, separated from the ice by a thin boundary layer. Provided that surface wind field is known, it is easy to calculate sea ice motion using this analytical model. We believe this analytical model is going to be a powerful tool for identifying and quantifying the mechanisms for sea ice variability.