Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Climate Change Could Release Large Amounts of Carbon

02.03.2004


Locked in Arctic Soils Into the Ocean, Researchers Say

The Arctic Ocean receives about ten percent of Earth’s river water and with it some 25 teragrams [28 million tons] per year of dissolved organic carbon that had been held in far northern bogs and other soils. Scientists had not known the age of the carbon that reaches the ocean: was it recently derived from contemporary plant material, or had it been locked in soils for hundreds or thousands of years and therefore not part of Earth’s recent carbon cycle?

Now, using carbon-14 data, scientists from the United States and Germany have been able to determine the approximate age of dissolved organic carbon in the Arctic for the first time. They report, in an article to be published this month in Geophysical Research Letters, that most of the carbon that reaches the ocean is relatively young at present, but that this could change. Warming of the Arctic, which has been documented in recent years, could affect northern peats, collectively one of the largest reservoirs of organic carbon on Earth. As the carbon-rich soils warm, the carbon is more susceptible to being transported to the ocean by rivers small and large, they say.

The researchers, headed by Ronald Benner of the University of South Carolina, studied four rivers in northern Russia and in Alaska, along with the Arctic Ocean itself. The carbon-14 dating method is not precise, because, for example, old and new dissolved organic carbon is typically mixed in a given sample, resulting in an average reading, and content of rivers varies by season as well. The scientists concentrated their study in periods of peak river discharge.

"Our results are not applicable to the sedimentary fraction of river discharge," Benner notes. "However, most of the organic carbon exported from land to the ocean is in dissolved form, and it is the dissolved components that track river water in the ocean."

River water tends to remain near the surface of the Arctic Ocean for five to 15 years, and the land-derived dissolved organic carbon from all sources and years is therefore mixed. Various samples gave radiocarbon average ages varying from 680 to 3,770 years, including both carbon from land-derived and marine sources. The researchers analyzed dissolved lignin phenols to determine the portion of a particular sample that had originated on land, as the compound is related only to terrestrial plant material.

The East Greenland Current is the major source of both Arctic Ocean water and its dissolved organic carbon component reaching the North Atlantic Ocean. The study concludes that the land- derived dissolved organic carbon reaching the Atlantic via this current is much younger than the marine component. In fact, up to half of it reaches the Atlantic, some three to 12 teragrams [three million to 13 million tons]. The fate of the young land-derived dissolved organic carbon in the Atlantic Ocean is uncertain, but there is no evidence of this material at lower latitudes in the Atlantic, the researchers say.

"This suggests most of the land-derived organic carbon ends up being oxidized to carbon dioxide and thus eventually cycles back into the atmosphere," says Benner. "If current warming trends in the Arctic continue, we can expect to see more of the old carbon now sequestered in northern soils enter the carbon cycle as carbon dioxide. This will act as a positive feedback, tending to enhance the greenhouse effect and accelerate global warming."

The research was funded by the U.S. National Science Foundation and the German Federal Ministry of Education and Research.

Harvey Leifert | AGU
Further information:
http://www.agu.org

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Researchers shoot for success with simulations of laser pulse-material interactions

29.03.2017 | Materials Sciences

Igniting a solar flare in the corona with lower-atmosphere kindling

29.03.2017 | Physics and Astronomy

As sea level rises, much of Honolulu and Waikiki vulnerable to groundwater inundation

29.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>