On the characteristics of Arctic sea-ice motion retrieved from buoy data of the MOSAiC expedition

Using data from the T69 and T70 snow and ice mass balance buoys deployed during the MOSAiC expedition from October 2019 to August 2020, this study investigates the characteristics of Arctic sea ice movement and their relationships with atmospheric and oceanic conditions by combining with reanalysis wind velocity data, ocean current data, and satellite-derived sea ice concentration (SIC) data. The results show that sea ice movement responds sharply to the wind field, with the wind factor reaching a maximum of 0.12. Furthermore, due to the reduced consolidation of sea ice after June 2020, the wind factor varied across a range of 0.02 to 0.12. Compared to wind velocity, ocean currents were slower, with the ice-to-current velocity ratio ranging primarily from 1 to 2. Using a SIC threshold of 80% in a piecewise multiple regression model, we find that the regression coefficients of wind velocity and ocean current velocity with respect to ice velocity depend strongly on SIC. For SIC≤80%, the regression coefficients are 0.0012 (wind) and 0.837 (current); for SIC > 80%, they are 0.017 (wind) and 0.646 (current). The results align well with established theoretical models. This study offers a theoretical basis for parameterizing the coupling of the wind–ice–ocean current velocity in sea ice dynamics.