Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A thermometer for the oceans

05.01.2018

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of the extra heat is absorbed by the oceans. This means that the average sea temperature can tell us a lot about the state of our climate, both today and in the past. However, it is difficult to determine an accurate average value across all sea depths and regions of the world.


Air bubbles in an ice core from the Antarctic: the ice is up to 24'000 years old.

Image: Bernhard Bereiter / Scripps Institution of Oceanography / Empa / University of Berne

The results of previous measurement methods heavily depend on location, season or sea depth, which can lead to distorted results. As part of the WAIS Divide Ice Core Project, an international research team led by Bernhard Bereiter from the Scripps Institution of Oceanography - now working at Empa and the University of Bern - has developed a method of measuring ocean temperatures over the last 24'000 years with high accuracy.

These measurements have now been published in Nature. "Our study clearly shows that the basic idea - the connection between the concentration of noble gases in the atmosphere and the average ocean temperature - is correct and that the method works," said Bereiter.

Eternal ice as contemporary witness

The work is based on ice cores from the Antarctic. The layers of eternal ice form an archive of the atmosphere, in which not only dust particles and solids but also air and other gases are trapped. In these bubbles one can determine the concentration of different gases. For once, it is not the usual suspects such as the greenhouse gases methane and carbon dioxide that play a role, but the noble gases krypton, xenon and argon, as Bereiter points out.

The principle can be explained as follows: cooling water absorbs noble gases from the atmosphere, while warming water releases noble gases into the atmosphere. The concentration of noble gases in the atmosphere thus allows conclusions to be drawn about the average global temperature of the sea - and not only the warmer ocean surface, but the mean temperature averaged over the entire mass of water to the very bottom of the sea.

A look into the past

The drill cores from the Antarctic ice cover the period of the past 24'000 years. During this time, the transition from the last ice age to the current warm age took place. This is also reflected in the results from drilling cores: the researchers found a significant rise in mean ocean temperatures; overall, the ocean warmed up by 2.6 degrees Celsius over a period of 10'000 years.

In the analysis of the data, Bereiter found that the increase in average global sea temperature is strongly correlated to the air temperature in Antarctica, which underscores the influence of the southern hemisphere on the global climate. Up to now, this type of temperature measurement can only be applied to very large changes such as the investigated transition from an ice age to a warm age. In theory, however, the method should also work to monitor current changes. These are (still) relatively small compared to the temperature changes investigated in the current study, which is why much more precise methods than are currently available are urgently needed, according to the Empa researcher.

Box: The WAIS Divide Ice Core Project

Ice cores are our only source of samples from the palaeo-atmosphere and are, therefore, extremely valuable for palaeo-climate research because they capture environmental parameters ranging, on local scales, from individual snowflakes to the entire Earth's atmosphere and, on time scales, from hours to hundreds of thousands of years.

They record numerous aspects of the Earth's climate system in a single archive with very high temporal resolution. The aim of the WAIS (West Antarctic Ice Sheet) Divide Ice Core Project is to investigate the climate from the last ice age to the present day with a much greater time resolution and dating accuracy than previously possible. This applies in particular to the analysis of atmospheric gases, water isotopes and chemicals.

Media Contact

Bernhard Bereiter
bernhard.bereiter@empa.ch
41-587-654-319

 @Empa_CH

http://www.empa.ch 

Bernhard Bereiter | EurekAlert!

More articles from Earth Sciences:

nachricht AWI researchers measure a record concentration of microplastic in arctic sea ice
24.04.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

nachricht Climate change in a warmer-than-modern world: New findings of Kiel Researchers
24.04.2018 | Christian-Albrechts-Universität zu Kiel

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: BAM@Hannover Messe: innovative 3D printing method for space flight

At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.

Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Quantum Technology for Advanced Imaging – QUILT

24.04.2018 | Information Technology

AWI researchers measure a record concentration of microplastic in arctic sea ice

24.04.2018 | Earth Sciences

Complete skin regeneration system of fish unraveled

24.04.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>