Because of the lifetime of methane and the very low hydroxyl concentrations over winter and early spring, methane is always high in March and April in the Arctic. I would like to see some ground based measurements for this year to compare to previous years and latitudes and isotope ratios before drawing any conclusions.
Thanks for commenting, Oliver. Only very little ground-based measurement is taking place at the moment and I strongly support more measuring to be done. The big danger is large abrupt releases that, combined with the impact of sea ice loss, threaten to cause huge warming in the Arctic, triggering further releases of methane from hydrates and from free gas in sediments under the sea. There's some 1700 Gt of methane in sediments underneath the East Siberian Arctic Shelf alone, with some 50 Gt ready for abrupt release any time. Release of just 1Gt of methane would have an immediate impact equivalent to over 100Gt of carbon dioxide (by comparison, carbon dioxide emissions from combustion of fossil fuel are currently some 33 Gt/year), threatening to trigger further methane releases to rapidly escalate into runaway global warming.