The surface waters of the Arctic Ocean could represent an important source of methane, reports a study published online in Nature Geoscience this week. Methane is a potent greenhouse gas, and its budget is a key source of uncertainty in the modelling of future climate change.

Eric Kort and colleagues measured atmospheric methane concentrations over the remote Arctic Ocean, up to latitudes of 82° north. They detected high concentrations of methane close to the ocean surface, indicative of an oceanic source equivalent to that seen on the Siberian shelf. High concentrations were found over openings in the sea ice and in regions of fractional sea-ice cover.

The researchers suggest that the Arctic Ocean could represent an important and climatically sensitive methane source.