Responses of the Arctic sea ice drift to general warming and intraseasonal oscillation in the local atmosphere

Sea ice drift in the Arctic Ocean impacts ice mass balance, ocean currents, ice deformation, and freshwater output into lower latitudes. Satellite observation reveals that the Arctic sea ice drift has accelerated under global warming. Meanwhile, previous studies also found that local atmospheric intraseasonal oscillation modulates the Arctic sea ice drift. However, the mechanisms linking the Arctic sea ice drift change to the general warming and intraseasonal oscillation in the local atmosphere are not clearly addressed. Based on a sea ice-ocean coupled model, this study finds that: (1) The atmospheric intraseasonal oscillation leads to a higher climatological sea ice drift speed despite it produces thicker ice in the Arctic marginal seas, since the elevating effect of increased wind speed yields the suppressing effect of increased ice thickness on sea ice drift speed. (2) The warming of local atmosphere results in substantial elevation of the Arctic sea ice drift speed through generating basin-scale reduction of sea ice thickness. Developing a more sophisticated sea ice dynamical equation may be an essential way to reduce the wide-existing positive bias in sea ice drift modeling.