Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientist links increase in greenhouse gases to changes in ocean currents

18.06.2010
Findings released during the annual Goldschmidt Conference at the University of Tennessee, Knoxville

By examining 800,000-year-old polar ice, scientists increasingly are learning how the climate has changed since the last ice melt and that carbon dioxide has become more abundant in the Earth's atmosphere.

For two decades, French scientist Jérôme Chappellaz has been examining ice cores collected from deep inside the polar ice caps of Greenland and Antarctica. His studies on the interconnecting air spaces of old snow -- or firn air -- in the ice cores show that the roughly 40 percent increase of carbon dioxide in the atmosphere since the Earth's last deglaciation can be attributed in large part to changes in the circulation and biological activity of the oceanic waters surrounding Antarctica.

Chappellaz presented his findings today in Knoxville, Tenn. during the Goldschmidt Conference, an international gathering of several thousand geochemists who converge annually to share their research on Earth, energy and the environment. The event, hosted by the University of Tennessee, Knoxville, and Oak Ridge National Laboratory, is taking place June 13-18.

By measuring the carbon isotopes in the firn air, scientists can pinpoint the source of atmospheric carbon during the millennia. Because living organisms at the surface of the oceans tend to take up the lighter of the carbon isotopes, 13C, and this isotope is then released when the organisms decay, scientists know the higher concentration of 13C is originating from the oceans.

Normally, the organisms die, sink to the ocean depths, and decompose, releasing carbon that remains stored in the cold, deep waters for centuries. But a growing concentration of the isotope 13C in the air during the last deglaciation indicates that this "old" carbon from decomposition was released from the southern polar waters, where the Antarctic Circumpolar Current transports more water than any other current in the world. Here, oceanic circulation is increasing in intensity and the deep water is releasing carbon dioxide at the surface.

For two decades, Chappellaz has examined polar ice cores to decipher how the primary greenhouse gases -- carbon dioxide, methane and nitrous oxide -- have changed in concentrations and ratios since ancient times and what has caused those changes. He notably showed for the first time the tight link existing between atmospheric methane and global climate at glacial-interglacial time scales. Chappellaz is research director at the Laboratoire de Glaciologie et Geophysique de Environnement in Grenoble, France.

The Goldschmidt Conference is named for Victor Goldschmidt (1888-1947), the Swiss-Norwegian scientist who is considered the father of geochemistry. This year's conference is sponsored by a number of international geochemical societies.

Whitney Holmes | EurekAlert!
Further information:
http://www.utk.edu

More articles from Earth Sciences:

nachricht In times of climate change: What a lake’s colour can tell about its condition
21.09.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

nachricht Did marine sponges trigger the ‘Cambrian explosion’ through ‘ecosystem engineering’?
21.09.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>