Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Oceanographers in noble pursuit

21.01.2002


The warm gulf stream (red) as it travels across the Atlantic.
© RSMAS


Vast warm and cold currents loop around the globe.


Argon traces keep tabs on climate change.

A new method for detecting tiny quantities of a rare form of the element argon may help oceanographers to trace the vast undersea currents that regulate our planet’s climate.

The technique can pick out one atom of the rare isotope argon-39 (39Ar) amid 10 million billion other atoms. That’s equivalent to detecting less than a litre of water in America’s 300-mile Lake Michigan.



Philippe Collon, a nuclear physicist at the Lamont-Doherty Earth Observatory in Palisades, New York, and his colleagues modified a particle accelerator at Argonne National Laboratory near Chicago to find and count 39Ar atoms. Counting 39Ar "is decidedly tricky", says Collon. His team are still perfecting their technique.

Previous efforts to count 39Ar atoms in seawater required thousands of litres of water and months of processing. Collon’s technique should be able to measure the isotope’s concentration in about 10 litres of water in a few hours.

Ideal gas

Rare 39Ar is produced in the atmosphere by cosmic rays hitting ordinary 40Ar - it then dissolves into the sea. Because the isotope decays at a fixed rate, the amount that remains at different depths tells researchers how long it has been since the water was last at the surface.

If the team can provide a reliable way to measure 39Ar, samples from the deep ocean could begin to yield new clues about the huge currents of the Great Ocean Conveyor Belt, and whether they are changing over time.

The conveyor belt is a giant loop that spans most of the world’s oceans - cold water moves from north to south along the sea floor, whereas warm water travels the other way at the surface. A complete cycle takes about 1,000 years.

The water in the conveyor belt carries much of the Earth’s heat, making it crucial to climate. Melting ice after the most recent Ice Age is thought to have halted the conveyor, causing sudden and massive shifts in climate. Some climatologists worry that melting of ice caps as a result of global warming could have the same effect.

The half-life of 39Ar - 269 years - "falls into a timescale that’s very useful for measuring climate change", says Bill Jenkins, who studies ocean circulation at the University of Southampton, UK.

Even better, Jenkins adds, argon is biologically inert. The movement of radioactive carbon in the bodies of plants and animals have confused previous ocean studies using that element.

But argon "doesn’t solve all of oceanography’s problems", warns Jenkins. There is still some question as to whether 39Ar is produced at a constant rate in the atmosphere. If it isn’t, fluctuations measured in the ocean may not have a direct bearing on ocean circulation.




TOM CLARKE | © Nature News Service
Further information:
http://www.nature.com/nsu/020114/020114-14.html

More articles from Earth Sciences:

nachricht A Volcanic Binge And Its Frosty Hangover
21.02.2019 | Universität Heidelberg

nachricht Researchers get to the bottom of fairy circles
21.02.2019 | Georg-August-Universität Göttingen

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: (Re)solving the jet/cocoon riddle of a gravitational wave event

An international research team including astronomers from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has combined radio telescopes from five continents to prove the existence of a narrow stream of material, a so-called jet, emerging from the only gravitational wave event involving two neutron stars observed so far. With its high sensitivity and excellent performance, the 100-m radio telescope in Effelsberg played an important role in the observations.

In August 2017, two neutron stars were observed colliding, producing gravitational waves that were detected by the American LIGO and European Virgo detectors....

Im Focus: Light from a roll – hybrid OLED creates innovative and functional luminous surfaces

Up to now, OLEDs have been used exclusively as a novel lighting technology for use in luminaires and lamps. However, flexible organic technology can offer much more: as an active lighting surface, it can be combined with a wide variety of materials, not just to modify but to revolutionize the functionality and design of countless existing products. To exemplify this, the Fraunhofer FEP together with the company EMDE development of light GmbH will be presenting hybrid flexible OLEDs integrated into textile designs within the EU-funded project PI-SCALE for the first time at LOPEC (March 19-21, 2019 in Munich, Germany) as examples of some of the many possible applications.

The Fraunhofer FEP, a provider of research and development services in the field of organic electronics, has long been involved in the development of...

Im Focus: Regensburg physicists watch electron transfer in a single molecule

For the first time, an international team of scientists based in Regensburg, Germany, has recorded the orbitals of single molecules in different charge states in a novel type of microscopy. The research findings are published under the title “Mapping orbital changes upon electron transfer with tunneling microscopy on insulators” in the prestigious journal “Nature”.

The building blocks of matter surrounding us are atoms and molecules. The properties of that matter, however, are often not set by these building blocks...

Im Focus: University of Konstanz gains new insights into the recent development of the human immune system

Scientists at the University of Konstanz identify fierce competition between the human immune system and bacterial pathogens

Cell biologists from the University of Konstanz shed light on a recent evolutionary process in the human immune system and publish their findings in the...

Im Focus: Transformation through Light

Laser physicists have taken snapshots of carbon molecules C₆₀ showing how they transform in intense infrared light

When carbon molecules C₆₀ are exposed to an intense infrared light, they change their ball-like structure to a more elongated version. This has now been...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Global Legal Hackathon at HAW Hamburg

11.02.2019 | Event News

The world of quantum chemistry meets in Heidelberg

30.01.2019 | Event News

Our digital society in 2040

16.01.2019 | Event News

 
Latest News

JILA researchers make coldest quantum gas of molecules

22.02.2019 | Physics and Astronomy

Understanding high efficiency of deep ultraviolet LEDs

22.02.2019 | Materials Sciences

Russian scientists show changes in the erythrocyte nanostructure under stress

22.02.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>