A new study by NASA scientists has found two million methane emission hotspots in the North American Arctic, according to a statement released by NASA's Jet Propulsion Laboratory (JPL) on Thursday.
"We consider hotspots to be areas showing an excess of 3,000 parts per million of methane between the airborne sensor and the ground," said lead author Clayton Elder of JPL. "And we detected two million of these hotspots over the land that we covered."
The paper, titled "Airborne Mapping Reveals Emergent Power Law of Arctic Methane Emissions," was published on Feb. 10 in the journal Geophysical Research Letters.
Within the dataset, the team also discovered a pattern: On average, the methane hotspots were mostly concentrated within about 40 meters of standing bodies of water, such as lakes and streams. After the 40-meter mark, the presence of hotspots gradually became sparser, and at about 300 meters from the water source, they dropped off almost completely.
The Arctic is one of the fastest warming places on the planet. As temperatures rise, the perpetually frozen layer of soil begins to thaw, releasing methane and other greenhouse gases into the atmosphere.
These methane emissions can accelerate future warming, but to understand to what extent, scientists need to know how much methane may be emitted, as well as when and what environmental factors may influence its release, said JPL.
"After two years of ground field studies that began in 2018 at an Alaskan lake site with a methane hotspot, we found abrupt thawing of the permafrost right underneath the hotspot," said Elder.
Being able to identify the likely causes of the distribution of methane hotspots will help scientists more accurately calculate this greenhouse gas' emissions across unobserved areas, according to JPL.