"What surprised me most is that the increase in volume of water flowing from the Atlantic into the Arctic Ocean appears to affect the exchange between the Laptev Sea and the atmosphere more than the change in temperature," says Iréne Wåhlström, oceanographic researcher at SMHI.
The water in the Arctic Ocean is stratified, and the warmer water that flows in from the Atlantic Ocean sinks to a deeper layer. It flows toward the Laptev Sea, shallow coastal waters in the Arctic north of Russia.
Researchers from SMHI have recently examined how the changes in the layer of Atlantic water affects the exchange of carbon dioxide and methane - both greenhouse gases - between the Laptev Sea and the atmosphere.
Longer ice-free periods cause greater exchange of carbon dioxide and methane
"Changes in the layer of Atlantic water are likely to produce a longer ice-free period in the Laptev Sea. This in turn will cause a longer period for photosynthesis in plant plankton, which utilises carbon dioxide from the sea. The sea will then absorb more carbon dioxide from the atmosphere," says Iréne Wåhlström.
Residual products are formed when organic material degrades in the sea. The stratification of surface water in the Laptev Sea disappears in the autumn, and different residues and substances, such as methane, come up to the surface from deeper water and can move into the atmosphere, where they affect the climate.