Featured Research

from universities, journals, and other organizations

Atmospheric Science Goes To Ground: Researchers Present New Findings On The Natural Hydrogen Cycle -- Earth's Soil May Be As Important As Its Atmosphere

Date:
August 28, 2003
Source:
National Science Foundation
Summary:
New evidence is emerging on the probable effects of an anticipated reliance on hydrogen as a fuel: surprisingly, we may need to look down in the ground rather up in the air, for answers.

Arlington, Va.-- New evidence is emerging on the probable effects of an anticipated reliance on hydrogen as a fuel: surprisingly, we may need to look down in the ground rather up in the air, for answers.

In the August 21 issue of the journal Nature, a group of researchers from the California Institute of Technology and other institutions reports results of a study of the atmospheric chemical reactions that produce and destroy hydrogen in the stratosphere. Funded in part by the National Science Foundation (NSF), the study concludes that most of the hydrogen eliminated from the atmosphere goes into the ground, and therefore that scientists will need to turn their focus toward developing an understanding of soil destruction of hydrogen to accurately predict whether hydrogen emissions will eventually accumulate in the air.

The researchers reached this conclusion after carefully measuring the abundance of a rare isotope of hydrogen known as deuterium. It has long been known that atmospheric hydrogen is rich in deuterium, but it was unclear why. The only reasonable explanation, scientists believed, is that atmospheric hydrogen is mostly destroyed by chemical reactions in the air, and that those reactions are relatively slow for deuterium-rich hydrogen, so it accumulates like salt in an evaporating pan of water.

If correct, this would mean that oxidizing atmospheric trace gases control the natural hydrogen cycle and that soils are relatively unimportant. But new research results suggest that one of the main natural sources of atmospheric hydrogen--the breakdown of methane--is actually responsible for the atmosphere's enrichment in deuterium. This result implies that reactions with atmospheric oxidants may be less important to the hydrogen cycle, and that uptake by soils, where microbial processes involve methane, is the driving force.

Hydrogen is a highly reactive element, but answers to the questions of when and where it reacts, and under what circumstances, are difficult to unravel. These questions are simplified in the stratosphere, where it's easier to single out and understand specific reactions. According to John Eiler, a geochemist at the California Institute of Technology and an author of the Nature paper, the new data were gathered from air samples taken from the stratosphere with one of the high-flying ER-2 planes operated by the NASA Dryden Flight Research Center in the Mojave Desert.

"We wanted to look at hydrogen in the stratosphere because it's easy to study the production of hydrogen from methane separate from other influences," Eiler explains. "It may seem odd to go to the stratosphere to understand what's happening in the ground, but this was the best way to get a global perspective on the importance of soils to the hydrogen cycle."

With precise information on the deuterium content of hydrogen formed from methane, the researchers were able to calculate that the soil uptake of hydrogen is as high as 80 percent. It is suspected that this hydrogen is used by soil-living microbes to carry on their biological functions, although the details of this process are poorly understood and have been the subject of only a few previous studies.

It seems likely, according to the scientists, that the hydrogen taken up by soils is relatively free of environmental consequences, but the question still remains of how much more hydrogen the soil can "consume." If future use of hydrogen in transportation results in a significant amount of leakage, then soil uptake must increase dramatically or it will be inadequate to cleanse the released hydrogen from the atmosphere, Eiler says.

"An analogy would be the discovery that trees and other plants get rid of some of the carbon dioxide that cars emit, but by no means all of it," he says. "So the question as we look toward a future hydrogen economy is whether [soil] microbes will be able to 'eat' the hydrogen fast enough."

Bruce Doddridge, program director in NSF's division of atmospheric sciences, which co-funded the research, said, "This carefully conducted research investigating the natural chemistry of sources and sinks affecting the abundance of hydrogen in the atmosphere results in the most accurate information to date, and appears to account for the atmospheric deuterium excess previously observed.

"A more accurate molecular hydrogen budget may have important implications as global fuel technology shifts its focus from fossil fuels to other sources," Doddridge added.

The lead author of the paper is Thom Rahn, a former post-doctoral fellow of Eiler's who is now affiliated with Los Alamos National Laboratory. The other authors are Paul Wennberg, an atmospheric chemist at Caltech; Kristie A. Boering and Michael McCarthy, both of UC Berkeley; Stanley Tyler of UC Irvine; and Sue Schauffler of the National Center for Atmospheric Research in Boulder, Colorado.

In addition to NSF, an independent federal agency that supports fundamental research in science and engineering, other supporters of the research were the Davidow Fund and General Motors Corp., the David and Lucile Packard Foundation, the NASA Upper Atmosphere Research Program, and the National Center for Atmospheric Research.


Story Source:

The above story is based on materials provided by National Science Foundation. Note: Materials may be edited for content and length.


Cite This Page:

National Science Foundation. "Atmospheric Science Goes To Ground: Researchers Present New Findings On The Natural Hydrogen Cycle -- Earth's Soil May Be As Important As Its Atmosphere." ScienceDaily. ScienceDaily, 28 August 2003. <www.sciencedaily.com/releases/2003/08/030826064652.htm>.
National Science Foundation. (2003, August 28). Atmospheric Science Goes To Ground: Researchers Present New Findings On The Natural Hydrogen Cycle -- Earth's Soil May Be As Important As Its Atmosphere. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2003/08/030826064652.htm
National Science Foundation. "Atmospheric Science Goes To Ground: Researchers Present New Findings On The Natural Hydrogen Cycle -- Earth's Soil May Be As Important As Its Atmosphere." ScienceDaily. www.sciencedaily.com/releases/2003/08/030826064652.htm (accessed July 25, 2014).

Share This




More Earth & Climate News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Bill Gates: Health, Agriculture Key to Africa's Development

Bill Gates: Health, Agriculture Key to Africa's Development

AFP (July 24, 2014) Health and agriculture development are key if African countries are to overcome poverty and grow, US software billionaire Bill Gates said Thursday, as he received an honourary degree in Ethiopia. Duration: 00:36 Video provided by AFP
Powered by NewsLook.com
Higgins Breaks Record at Mt. Washington

Higgins Breaks Record at Mt. Washington

Driving Sports (July 24, 2014) Subaru Rally Team USA drivers David Higgins and Travis Pastrana face off against a global contingent of racers at the annual Mt. Washington Hillclimb in New Hampshire. Includes exclusive in-car footage from Higgins' record attempt. Video provided by Driving Sports
Powered by NewsLook.com
Storm Kills Three, Injures 20 at Virginia Campground

Storm Kills Three, Injures 20 at Virginia Campground

Reuters - US Online Video (July 24, 2014) A likely tornado tears through an eastern Virginia campground, killing three and injuring at least 20. Linda So reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins