Space-time variations of sea ice in Bohai Sea in the winter of 2009-2010 simulated with a coupled ocean and ice model

Sea ice variations in the severe winter of 2009-2010 in the Bohai Sea are simulated with a coupled ocean and ice model. The modelled ice coverage shows good agreement with satellite observations. Integrated over three sub-regions [the extended Liaodong Bay (LDB), Bohai Bay, and Laizhou Bay], the temporal variations of ice volume and surface air temperature are well correlated at time scales of 5-15 days and longer than 15 days. In LDB, at time scales of 5-15 days, the maximum ice volume lags the minimum surface air temperature by 42 h on average. In LDB, a significant amount of ice formed in the northern part is advected southward and then melts, and the trajectories of the positions of ice centroids further demonstrate the distinct trend of southward ice drift in this area. The impacts of winds are obvious during strong wind events. The results of multiple linear regression suggest that the hourly ice drift variations are mainly due to surface currents with significant tidal signals, and the daily ice drift variations can be mostly attributed to surface winds and secondly to surface ocean currents.

Automated summary

The study simulating sea ice variations in the Bohai Sea during the severe winter of 2009-2010 shows a strong correlation between ice volume and surface air temperature, indicating the influence of temperature fluctuation on sea ice coverage. In the Liaodong Bay, the maximum ice volume lags behind the minimum surface air temperature at time scales of 5-15 days, and ice formed in the northern part is advected southward and melts. The impact of winds, especially during strong wind events, is significant in driving ice drift variations.