Freshwater Current Between the Kara, Laptev Seas Discovered


Photo: Nikolay Gernet / Geo Photo

The discovery is fundamentally important to have more accurate forecasts of the ice strength along the Northern Sea Route.

Russian researchers found in the Arctic Ocean a freshwater current that carries waters of the largest Siberian rivers from the Kara Sea to the Laptev Sea. This process prevents excessive desalination of the Kara Sea, thus affecting the nature of ice formation in its waters, the Russian Science Foundation's press office said.

The discovery of this subglacial current is fundamentally important to have more accurate forecasts of the ice strength along the Northern Sea Route. For example, the ice that forms and grows from desalinated waters is 10-15% stronger than the ice formed from salty sea waters, the press office quoted a senior researcher at the Ocean Studies Institute (the Russian Academy of Sciences, Moscow) as saying.

The researchers came to this conclusion after winter-spring studies between 2021 and 2023, where they measured the current's speed, temperature and salinity of water in the Kara Sea and the Laptev Sea. The researchers carried out the measurements both off icebreakers and off a floating station anchored in the Vilkitsky Strait that connects the Kara Sea and the Laptev Sea.

The data collected by the scientists in the strait revealed the existence of a previously unknown flow of desalinated water, moving from west to east in late autumn and early winter. As a result, fresh waters discharged into the Kara Sea by the Ob and the Yenisei Rivers, the world's two largest northern rivers, were transferred into the Laptev Sea due to the influence of the Coriolis force generated by the Earth's rotation, and as a result of the difference in buoyancy between fresh and salty waters.

Due to the Earth’s rotation, desalinated waters of lower density are forming under the ice a powerful current along the coast and get carried away eastwards - into the Laptev Sea. As a result of this process, in January, the surface layer in the Kara Sea's central part becomes salty again, the press office quoted the chief researcher at MIPT (Moscow Institute of Physics and Technology) as saying.

According to the scientists, these periodic changes in the salinity of the Kara Sea and the Laptev Sea affect the nature and strength of the ice that forms in autumn and winter. This should be taken into account when laying icebreaker routes via the Northern Sea Route, as well as when forecasting how the ice cover in the Russian Arctic will change as the climate changes.