Forum for Science, Industry and Business

Oceanographers in noble pursuit

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.

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...