Anomalies of sea-ice transports in the Arctic

Abstract

In the Arctic, sea-ice motion and ice export are prominent processes and good indicators of Arctic climate system variability. Sea-ice drift is simulated using a dynamic-thermodynamic sea-ice model, validated with retrievals from SSM/I satellite observations. Both datasets agree well in reproducing the main Arctic drift patterns. In order to study inner Arctic transports and ice volume anomalies, the Arctic Ocean is split by ten boundaries, separating the central Arctic Ocean from the Nordic and marginal seas. It is found that the already dominant sea-ice export through Fram Strait has increased at the expense of export through the Barents Sea in the most recent years investigated. Furthermore, ice export from the Eurasian marginal seas increased slightly, followed by greater ice production during the winter. In contrast to this, the sea-ice volume moved within the Beaufort Gyre distinctly decreased. In total, the ice volume in the central Arctic decreased during the 40 year period covered by this study. The changes in the ice volume correspond to two wind-driven circulation regimes of the Arctic sea-ice motion, which recur approximately every 11 years. For the volume anomalies we derived a correlation of -0.59 to the North Atlantic Oscillation (NAO) index, lagging the NAO by 2 years.