Estimation of duration and its changes in Lagrangian observations relying on ice floes in the Arctic Ocean utilizing a sea ice motion product

Abstract

Since the 1890s, buoy- and camp-based Lagrangian observations relying on ice floes have been indispensable for data acquisition in the difficult-to-access central Arctic Ocean in winter. Evaluating the potential observation duration, and how it changes in association with changes in the Arctic climate system, is crucial for planning ice camp or buoy deployment. Using a remote sensing sea ice motion product, we reconstructed sea ice drift trajectories for each annual cycle from 1979-1980 to 2022-2023 and identified ideal areas for ice camp or buoy deployment in the central Arctic Ocean. The results show that, based on the setup time of 1 October, areas centered at 82° N and 160° E, near north of the East Siberian and Laptev seas, with a size of 7.0 × 105 km2, could ensure Lagrangian observations for at least 9 months, with the drifting remaining in the ice zone and not entering the exclusive economic zones (EEZs) of Arctic coastal countries, with the probability of 75.0 %-90.9 % over 44 years. The potential deployment areas favored ice advection to the Transpolar Drift (TPD) region relative to the Beaufort Gyre (BG) region. Ice trajectory terminal points did not reveal an obvious long-term tendency, but they were regulated by large-scale atmospheric circulation patterns, especially those in the early drifting stage in autumn (OND). In particular, the autumn east-west surface air pressure gradient across the central Arctic and the Arctic dipole anomaly indices significantly influenced the terminal points of ice trajectories after 9 months, and their extreme positive phases were found to expand the ideal deployment areas. The rate of increase in near-surface air temperatures in autumn-spring along the trajectories was more pronounced in the TPD region than that in the BG region. The sea ice response to wind stress significantly intensified in recent Lagrangian observations, suggesting stronger ice dynamic processes as the sea ice thins. The geopolitical boundaries of EEZs have a significant impact on the sustainability of the Lagrangian observations, limiting them to a maximum of 10 months. Without this restriction, the potential Lagrangian observations in the BG and TPD regions would expand southward, with an increased duration by 20.5 and 5.0 d, respectively, compared to those with the EEZ restriction.