. Earth Science News .

Study Finds Surprising Arctic Methane Emission Source
by Staff Writers
Pasadena CA (JPL) Apr 26, 2012

A new airborne study with NASA contributions measured surprising levels of the potent greenhouse gas methane coming from cracks in Arctic sea ice and areas of partial sea ice cover. This image was taken over the Arctic Ocean at a latitude of approximately 71 degrees North on April 15, 2010. Image credit: NASA/JPL.

The fragile and rapidly changing Arctic region is home to large reservoirs of methane, a potent greenhouse gas. As Earth's climate warms, the methane, frozen in reservoirs stored in Arctic tundra soils or marine sediments, is vulnerable to being released into the atmosphere, where it can add to global warming.

Now a multi-institutional study by Eric Kort of NASA's Jet Propulsion Laboratory, Pasadena, Calif., has uncovered a surprising and potentially important new source of Arctic methane: the ocean itself.

Kort, a JPL postdoctoral scholar affiliated with the Keck Institute of Space Studies at the California Institute of Technology in Pasadena, led the analysis while he was a student at Harvard University, Cambridge, Mass.

The study was conducted as part of the HIAPER Pole-to-Pole Observations (HIPPO) airborne campaign, which flew a specially instrumented National Science Foundation (NSF)/National Center for Atmospheric Research (NCAR) Gulfstream V aircraft over the Pacific Ocean from nearly pole to pole, collecting atmospheric measurements from Earth's surface to an altitude of 8.7 miles (14 kilometers).

The campaign, primarily funded by NSF with additional funding from NCAR, NASA and the National Oceanic and Atmospheric Administration, was designed to improve our understanding of where greenhouse gases are originating and being stored in the Earth system.

During five HIPPO flights over the Arctic from 2009 to 2010, Kort's team observed increased methane levels while flying at low altitudes over the remote Arctic Ocean, north of the Chukchi and Beaufort Seas. The methane level was about one-half percent larger than normal background levels.

But where was the methane coming from? The team detected no carbon monoxide in the atmosphere that would point to possible contributions from human combustion activities. In addition, based on the time of year, location and nature of the emissions, it was extremely unlikely the methane was coming from high-latitude wetlands or geologic reservoirs.

By comparing locations of the enhanced methane levels with airborne measurements of carbon monoxide, water vapor and ozone, they pinpointed a source: the ocean surface, through cracks in Arctic sea ice and areas of partial sea ice cover.

The cracks expose open Arctic seawater, allowing the ocean to interact with the air, and methane in the surface waters to escape into the atmosphere. The team detected no enhanced methane levels when flying over areas of solid ice.

Kort said previous studies by others had measured high concentrations of methane in Arctic surface waters, but before now no one had predicted that these enhanced levels of ocean methane would find their way to the overlying atmosphere.

So how is the methane being produced? The scientists aren't yet sure, but Kort hinted biological production from living things in Arctic surface waters may be a likely culprit.

"It's possible that as large areas of sea ice melt and expose more ocean water, methane production may increase, leading to larger methane emissions," he said. He said future studies will be needed to understand the enhanced methane levels and associated emission processes and to measure their total contribution to overall Arctic methane levels.

"While the methane levels we detected weren't particularly large, the potential source region, the Arctic Ocean, is vast, so our finding could represent a noticeable new global source of methane," he added.

"As Arctic sea ice cover continues to decline in a warming climate, this source of methane may well increase. It's important that we recognize the potential contribution from this source of methane to avoid falsely interpreting any changes observed in Arctic methane levels in the future."

Related Links
Keck Institute of Space Studies
Beyond the Ice Age

Get Our Free Newsletters Via Email
Buy Advertising Editorial Enquiries


. Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Arctic marine mammals and fish populations on the rise
Montreal (AFP) April 23, 2012
Arctic marine mammals and fish populations are on the rise, according to a report released on Monday by the the Arctic Council's biodiversity working group at a Montreal conference. In fact fish populations have risen dramatically, according to the findings of the Circumpolar Biodiversity Monitoring Program, the Zoological Society of London, and the World Wildlife Fund. The three organiz ... read more

Construction of Chernobyl shelter starts on anniversary

Sean Penn urges more aid for Haiti

Hong Kong holds nuclear accident drill

European body sees broad failures in Libya migrant deaths

Google sells 3D modeling application SketchUp

The ultimate babysitter? iPads for infants stir debate

TED blends animation with education at new website

360-Degree MEADS Radar Begins Integration Testing

Xayaburi Dam construction to continue?

Research is ensuring stormwater systems are designed for the future

Planned dams in Amazon may have largely negative ecosystem impact

Bangladesh faces water problems

Study Finds Surprising Arctic Methane Emission Source

State of Himalayan glaciers less alarming than feared

Breaking the Ice on Icebergs

Arctic marine mammals and fish populations on the rise

Hong Kong suspends poultry imports from China province

New South Asia network to tackle 'massive' climate adaptation challenge

Potato consumption lower than expected

World's first handmade cloned transgenic sheep born in China

GPS could speed up tsunami alert systems: researchers

NASA's New Satellite Movie of One Week's Ash Activity from Mexico's Popocatepetl Volcano

Warning signs from ancient Greek tsunami

Hundreds evacuated as Russian village flooded

Sierra Leone's gruesome 10-year civil war

Stench of death in Heglig, where Sudan says 1,200 died

Mali junta yet to return to barracks: groups

G.Bissau will 'defend itself' if foreign troops sent: junta

Rio Summit must address population growth: scientists

Scientists show how social interaction and teamwork lead to human intelligence

NIST mini-sensor measures magnetic activity in human brain

Meat eating led to earlier weaning, helped humans spread across globe

Memory Foam Mattress Review

Newsletters :: SpaceDaily Express :: SpaceWar Express :: TerraDaily Express :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News


The content herein, unless otherwise known to be public domain, are Copyright 1995-2012 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement