Dissolved methane (CH₄) concentrations from the U.S. GEOTRACES Arctic cruise (HLY1502; GN01) on USCGC Healy from August to October 2015

This dataset reports dissolved methane (CH₄) concentrations from the US GEOTRACES Arctic Expedition on USCGC Healy (GN01, HLY1502) from August to October 2015. Seawater samples were collected using the ODF rosette. Both GEOTRACES samples and GO-SHIP samples from the same cruise were analyzed. Methane was analyzed using cavity ringdown spectroscopy to determine its concentration in an equilibrated headspace. Arctic waters are a possibly significant source of this Greenhouse Gas to the atmosphere and global change is likely exacerbating its release. Methane is also a potentially valuable indicator of interactions with the shelf as well as of river inputs. Dissolved methane concentrations in this section were highest over the continental shelves and slope, which supports our understanding of the major sources of methane (i.e., from microbes in oxygen-limited sediments, from gas seeps, and from gas-hydrates).