Publication: Advances in Polar Science (APS). Vol.33, No.3, 204-219, September 2022
Authors: LEI Ruibo, ZHANG Fanyi and ZHAI Mengxi
DOI: 10.13679/j.advps.2016.3.00139
CNARC member: Polar Research Institute of China (PRIC)
Abstract: Rapid changes in the Arctic climate and those in Arctic sea ice in recent decades are closely coupled. In this study, we used atmospheric reanalysis data and satellite remote sensing products to identify anomalies of meteorological and sea ice conditions during the ice season of 2018–2019 relative to climatological means using a Lagrangian methodology. We obtained the anomalies along the drifting trajectories of eight sea ice mass balance buoys between the marginal ice zone and the pack ice zone in the western Arctic Ocean (~160°W–170°W and 79°N–85°N) from September 2018 to August 2019. The temporary collapse of the Beaufort High and a strong positive Arctic Dipole in the winter of 2018–2019 drove the three buoys in the north to drift gradually northeastward and merge into the Transpolar Drift Stream. The most prominent positive temperature anomalies in 2018–2019 along the buoy trajectories relative to 1979–2019 climatology occurred in autumn, early winter, and April, and were concentrated in the southern part of the study area; these anomalies can be partly related to the seasonal and spatial patterns of heat release from the Arctic ice-ocean system to the atmosphere. In the southern part of the study area and in autumn, the sea ice concentration in 2018–2019 was higher than that averaged over the past 10 years. However, we found no ice concentration anomalies for other regions or seasons. The sea ice thickness in the freezing season and the snow depth by the end of the winter of 2018–2019 can also be considered as normal. Although the wind speed in 2018–2019 was slightly lower than that in 1979 2019, the speed of sea ice drift and its ratio to wind speed were significantly higher than the climatology. In 2019, the sea ice surface began to melt at the end of June, which was close to the 1988–2019 climatology. However, spatial variations in the onsets of surface melt in 2019 differed from the climatology, and can be explained by the prevalence of a high-pressure system in the south of the Beaufort Sea in June 2019. In addition to seasonal variations, the meteorological and sea ice anomalies were influenced by spatial variations. By the end of summer 2019, the buoys had drifted to the west of the Canadian Arctic Archipelago, where the ice conditions was heavier than those at the buoy locations in early September 2018. The meteorological and sea ice anomalies identified in this study lay the foundations for subsequent analyses and simulations of sea ice mass balance based on the buoy data.
Key words: sea ice, air temperature, climate, snow, motion, Arctic Ocean
