Methane venting through cracks in the sea ice
Arctic sea ice is actually a collection of smaller pieces that constantly shift, crack, and grind against one another as they are jostled by winds and ocean currents. Cracks, or leads, in the ice can open at any time of the year, but they are especially common during the spring and summer.
22 April 2012
Hippo search project data is available here.
The project was under the UCAR for research.
The research was published 'Atmospheric observations of Arctic Ocean methane emissions up to 82° north' in 2012.
During five Arctic fly overs with on board plane atmospheric monitoring instrument 'HIPPO' flights from 2009 to 2010, a research team observed increased methane levels while flying at low altitudes over the remote Arctic Ocean, north of the Chukchi and Beaufort Seas.
Atmospheric observations of Arctic Ocean methane emissions Kort et al Nature April 2012
ARCTIC OCEAN VENTING METHANE
It had always been assumed by climate change science that the shallow pools of Arctic methane in and below the Arctic continental shelves would not vent or escape through the water to the atmosphere because even if it were released (due to Arctic ocean warming) it would all be dissolved in the sea water. Russian research over the vast East Siberian Shelf was the first to disagree with this by finding large local concentrations of methane in the air over the sea surface.
In October 2019 Russian research discovered methane visibly bubbliing to the surface of the East Siberian Sea. This is from the Russian media report