AMEG Poster, April 25, 2012

Study Finds Surprising Arctic Methane Emission Source

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."

The study, published April 22 in Nature Geoscience, included participation from JPL and Caltech; NSF, Arlington, Va.; NOAA's Earth System Research Laboratory, Boulder, Colo.; the University of Colorado's Cooperative Institute for Research in Environmental Sciences, Boulder; Harvard University, Cambridge, Mass.; Princeton University, Princeton, New Jersey; Universidad Nacional de Colombia, Bogota, Colombia; and Science and Technology Corporation, Boulder, Colo. JPL is a division of Caltech.


Source: jpl.nasa.gov
Journal reference: Nature Geoscience, DOI: 10.1038/ngeo1452
nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1452.html

Will Arctic sea ice collapse in 2014?

There has been some discussion recently about extrapolating Arctic sea ice data, particularly for data relating to annual minimum sea ice. I've been trying which kind of trendline fits best and my conclusion is that a trendline pointing at 2014 fits the data best (image left). The respective dataset, on the left underneath, was produced by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS, Zhang and Rothrock, 2003) developed at Polar Science Center, Applied Physics Laboratory, University of Washington, and is displayed below interactively (hover over blue line to see the respective volume data for that year). As mentioned in the discussion, some ice may persist close to Greenland for a few years more, since Greenland constitutes a barrier that holds the sea ice in place. Similarly, it is suggested that natural variability could prolong the ice longer than expected. However, such arguments offer no reason to rule out an imminent collapse of the sea ice, since natural variability works both ways, it could bring about such a collapse either earlier or later than models indicate. In fact, the thinner the sea ice gets, the more likely an early collapse is to occur. It is accepted science that global warming will increase the intensity of extreme weather events, so more heavy winds and more intense storms can be expected to increasingly break up the remaining ice in future, driving the smaller parts out of the Arctic Ocean more easily. Much of the sea ice loss already occurs due to sea ice moving along the edges of Greenland into the Atlantic Ocean. Could you think of any reason why Arctic sea ice would NOT collapse in 2014?

Related:
Arctic sea ice volume on track to reach zero around 2015
Greenland is melting at incredible rate
Arctic Sea Ice
When the sea ice is gone

Discussion: Should patent law apply to geo-engineering?

David Keith, a Harvard University professor and an adviser on energy to Microsoft founder Bill Gates, said he and his colleagues are researching whether the federal government could ban patents in the field of solar radiation, according to a report in Scientific American.

Some of his colleagues last week traveled to Washington, D.C., where they discussed whether the U.S. Patent Office could ban patents on the technology, Keith said.

"We think it's very dangerous for these solar radiation technologies, it's dangerous to have it be privatized," Keith said. "The core technologies need to be public domain."

As suggested by Sam Carana, a declaration of emergency, as called for by the Arctic Methane Emergency Group (AMEG), could be another way to deal with this issue.

A declaration of Emergency could give governments the power to overrule patents, where they stand in the way of fast-tracking geo-engineering projects proposed under emergency rules.Thus, patents don't need to be banned, prohibited or taken away; instead, patent will continue to apply in all situations other than the emergency situation, while new patents could also continue to be lodged during the emergency period.

Even where patent are directly applicable to proposed projects, patent law would still continue to apply, the emergency rules would merely allow governments to proceed in specific situations, avoiding that projects are being held up by legal action, exorbitant prices or withholding of crucial information.

A declaration of emergency could also speed up projects by removing the need to comply with all kinds of time-consuming bureaucratic procedures, such as the need to get formal approvals and permits from various departments, etc. This brings us to the need to comply with international protocols and agreements. If declared internationally, a declaration of emergency could overrule parts of such agreements where they pose unacceptable delays and cannot be resolved through diplomacy.

The issue is also discussed at the Geoengineering group at Google.