Odden ice tongue reappears near Jan Mayen after years of decline

A distinctive Arctic sea-ice formation has shown signs of returning near Jan Mayen, a Norwegian volcanic island in the Greenland Sea, after becoming much less common over the past two decades. The feature, known as the Odden ice tongue, is a long, curved stretch of ice that historically formed near the West Jan Mayen Ridge. It was particularly prominent during the 1980s and 1990s, but appeared less regularly after the early 2000s as the regional ice edge retreated. According to reporting by Phys.org on a study published in Polar Science, researchers analyzed radar and other satellite observations from 2017 through 2024. They compared the imagery with an independent record of sea-ice concentration and with air and sea-surface temperature data. The analysis found a marked increase in sea ice around Jan Mayen during 2023 and early 2024. The largest recorded extent came in January 2024, when ice covered approximately 20,300 square kilometers, or 39.5% of the study area. The second-largest extent occurred in March 2023, at about 14,500 square kilometers. The 2023–24 ice distribution followed the Jan Mayen Current and resembled the early stages of the historic Odden formation. However, the researchers said it did not reach the feature’s former maximum size. Ice coverage later fell to levels more typical of recent years during 2024. The study does not attribute the increase to one factor. Researchers identified a possible combination of colder local seawater, brief periods of cold weather, winds, salinity changes and Arctic ice carried into the region by currents. They also suggest that increased freshwater transport may have played an important role. Freshwater entering the Greenland Sea can alter seawater salinity and make conditions more favorable for freezing. Periods of extensive ice in the region have previously been associated with Great Salinity Anomalies, which occur when large amounts of relatively fresh water move through the ocean. It remains uncertain whether the Odden ice tongue will appear again or whether the recent resurgence was a one-time event. The researchers said improved monitoring of freshwater and ice transport could help clarify possible effects on ocean circulation and regional ecosystems.