Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Surface of the oceans affects climate more than thought

30.09.2015

The oceans seem to produce significantly more isoprene, and consequently affect stronger the climate than previously thought. This emerges from a study by the Institute of Catalysis and Environment in Lyon (IRCELYON, CNRS / University Lyon 1) and the Leibniz Institute for Tropospheric Research (TROPOS), which had studied samples of the surface film in the laboratory. The results underline the global significance of the chemical processes at the border between ocean and atmosphere, write the researchers in the journal Environmental Science & Technology.

Isoprene is a gas that is formed by both the vegetation and the oceans. It is very important for the climate because this gas can form particles that can become clouds and then later affect temperature and precipitation. Previously it was assumed that isoprene is primarily caused by biological processes from plankton in the sea water.


In the laboratory of IRCELYON in Lyon the seawater was artificially illuminated by the group led by Dr. George Christian. The resultant gases were analysed to investigate the photochemical processes.

Photo: IRCELYON

The atmospheric chemists from France and Germany, however, could now show that isoprene could also be formed without biological sources in surface film of the oceans by sunlight and so explain the large discrepancy between field measurements and models. The new identified photochemical reaction is therefore important to improve the climate models.

The oceans not only take up heat and carbon dioxide from the atmosphere, they are also sources of various gaseous compounds, thereby affecting the global climate. A key role is played by the so-called surface microlayer (SML), especially at low wind speed. In these few micrometers thin layer different organic substances such as dissolved organic matter, fat and amino acids, proteins, lipids are accumulating as well as trace metals, dust and microorganisms.

For the now published study, the research team took samples from the Norther Atlantic Ocean. The surface film was collected in the Raunefjord near Bergen in Norway. For this purpose, a glass plate is immersed in water and then again carefully pulled from the water. The 200 micron thin film sticks to the glass and is then scraped off with a wiper.

The sample thus obtained is analyzed in the laboratory later. At the Institute of Catalysis and Environment in Lyon (IRCELYON), which belongs to the French research organization CNRS and the University of Lyon 1, the team investigated its photochemical properties during which collected samples were irradiated with light and the gases were analyzed: it became clear that isoprene was produced in magtnetudes that were previously attributed solely to plankton.

"We were able for the first time trace back the production of this important aerosol precursor to abiotic sources, so far global calculations consider only biological sources," explains Dr. Christian George from IRCELYON.

Thus, it is now possible to estimate more closely the total amounts of isoprene, which are emitted. So far, however, local measurements indicated levels of about 0.3 megatonnes per year, global simulations of around 1.9 megatons per year. But the team of Lyon and Leipzig estimates that the newly discovered photochemical pathway alone contribute 0.2 to 3.5 megatons per year additionally and could explain the recent disagreements.

"The existence of the organic films at the ocean surface due to biological activities therefore influences the exchange processes between air and sea in a unexpected strong way. The photochemical processes at this interface could be a very significant source of isoprene", summarizes Prof. Hartmut Herrmann from TROPOS.

The processes at the boundary between water and air are currently of great interest in science: In August, the team from the CNRS and TROPOS presented evidence in Scientific Reports, the open-access journal of Nature, that dissolved organic material in the surface film is strengthening the chemical conversion of saturated fatty acids into unsaturated gas phase products under the influence of sunlight.

For the first time it was realized that these products have to be of biological origin not only, but also abiotic processes at the interface between two media have the potential to produce such molecules. In early September another team from Canada, the US, Great Britain and Germany showed in the journal Nature that organic material from the surface film of the oceans can be an important source for the formation of ice in clouds over remote regions of the North Atlantic, North Pacific and Southern Ocean.

The recent publication of the teams from CNRS and TROPOS in Environmental Science & Technology provides indications how the climate models in the important details of the influence of isoprene could be improved. Because of the great importance this paper will be open access as "Editor's Choice".
Tilo Arnhold

Publications:
Raluca Ciuraru, Ludovic Fine, Manuela van Pinxteren, Barbara D'Anna, Hartmut Herrmann, and Christian George (2015): Unravelling new processes at interfaces: photochemical isoprene production at the sea surface. Environmental Science & Technology. Just Accepted Manuscript
DOI: 10.1021/acs.est.5b02388
http://dx.doi.org/10.1021/acs.est.5b02388The study was funded by the European Research Council ERC (ERC Grant Agreement 290852 - Airsea).

Raluca Ciuraru, Ludovic Fine, Manuela van Pinxteren, Barbara D’Anna, Hartmut Herrmann & Christian George (2015): Photosensitized production of functionalized and unsaturated organic compounds at the air-sea interface. Scientific Reports, 5:12741, DOI: 10.1038/srep12741
http://dx.doi.org/10.1038/srep12741The study was funded by the European Research Council ERC (ERC Grant Agreement 290852 - Airsea).

Further Information:
Dr. Christian George (en. + fr.)
Institut de Recherches sur la Catalyse et l'Environnement de Lyon (IRCELYON)
Tel: +33-(0)472 44 54 92
http://www.ircelyon.univ-lyon1.fr/syrcel/card/CGO
and
Prof. Dr. Hartmut Herrmann, Dr. Manuela van PinxterenLeibniz Institute for Tropospheric Research (TROPOS)
Tel. +49-341-2717-7024, -7102
http://www.tropos.de/en/institute/about-us/employees/hartmut-herrmann/
http://www.tropos.de/en/institute/about-us/employees/manuela-van-pinxteren/
or
Tilo Arnhold, public relation of TROPOS
Tel. +49-341-2717-7189
http://www.tropos.de/en/current-issues/press-releases/

Links:
Climat : l’impact des réactions à la surface des océans sur l’atmosphère (press release of CNRS in French)
http://www.cnrs.fr/inc/communication/direct_labos/george4.htm

METEOR expedition „BioChemUpwell“ takes a close look at upwelling zones in the Baltic Sea (Press release of 23rd Juli 2015)
http://www.tropos.de/en/current-issues/press-releases/details/meteor-expedition-...

Sea-surface microlayer
http://www.io-warnemuende.de/bio-ag-molbio-surface-microlayer.html

The Leibniz Association connects 89 independent research institutions that range in focus from the natural, engineering and environmental sciences via economics, spatial and social sciences to the humanities. Leibniz Institutes address issues of social, economic and ecological relevance. They conduct knowledge-driven and applied basic research, maintain scientific infrastructure and provide research-based services. The Leibniz Association identifies focus areas for knowledge transfer to policy-makers, academia, business and the public. Leibniz Institutes collaborate intensively with universities – in the form of “WissenschaftsCampi” (thematic partnerships between university and non-university research institutes), for example – as well as with industry and other partners at home and abroad. They are subject to an independent evaluation procedure that is unparalleled in its transparency. Due to the institutes’ importance for the country as a whole, they are funded jointly by the Federation and the Länder, employing some 18,100 individuals, including 9,200 researchers. The entire budget of all the institutes is approximately 1.64 billion EUR. http://www.leibniz-association.eu

Weitere Informationen:

http://www.tropos.de/en/current-issues/press-releases/details/surface-of-the-oce...

Tilo Arnhold | Leibniz-Institut für Troposphärenforschung e. V.

More articles from Earth Sciences:

nachricht Predicting eruptions using satellites and math
28.06.2017 | Frontiers

nachricht NASA sees quick development of Hurricane Dora
27.06.2017 | NASA/Goddard Space Flight Center

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Supersensitive through quantum entanglement

28.06.2017 | Physics and Astronomy

X-ray photoelectron spectroscopy under real ambient pressure conditions

28.06.2017 | Physics and Astronomy

Mice provide insight into genetics of autism spectrum disorders

28.06.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>