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

Abstract. Since the 1890s, buoy- and camp-based Lagrangian observations relying on ice floes, have been pivotal for data acquisition during winter in the central Arctic Ocean due to the inaccessibility of most research vessels. Evaluating the observation duration and its changes associated with changes in Arctic climate system, is crucial for the planning of ice camp/buoy deployment. Using remote sensing sea ice motion product, we reconstructed sea ice drift trajectories for each year in 1979–2020 and identified ideal deployment areas of ice camp/buoy in the central Arctic Ocean. The results show that, based on the setup time of October 1, the areas centered at 82° N and 160° E near the north of East Siberian and Laptev seas, with a size of 7.6×10⁵ km², could ensure Lagrangian observations for at least 9 months with the drifting maintaining in the ice zone and not entering the exclusive economic zones (EEZs) of Arctic coastal countries, with the probability of 76.2 %–92.9 % during 42 years. The potential deployment areas favored ice advection to the Transpolar Drift (TPD) region relative to the Beaufort Gyre (BG) region. Ice trajectory endpoints did not reveal an obvious long-term tendency, but were regulated by large-scale atmospheric circulation patterns, especially the atmospheric patterns in the early drifting stage of autumn (OND). In particular, the autumn east-west surface air pressure gradient across the central Arctic and the Arctic Dipole Anomaly indices significantly influenced endpoints of ice trajectories after 9 months and can expand ideal Lagrangian observation areas under scenarios with their extreme positive phases. The increasing rate of near-surface air temperatures from autumn to 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 dynamic processes as the sea ice thinning. Geopolitical boundaries of EEZs have a significant impact on the sustainability of the Lagrangian observations, making it rarely exceed 10 months. Without this restriction, the potential Lagrangian observations in the BG and TPD regions would expand southward.