Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tracking down volatile mercury in the Atlantic

24.10.2011
Marine chemists from Warnemünde identify unexpected places and seasons of higher emission.

For the first time, mercury emissions of the Atlantic Ocean were investigated by comprehensive measurements, performed under the leadership of researchers from the Leibniz Institute of Baltic Sea Research in Warnemünde.

The scientists Joachim Kuss, Christoph Zülicke, Christa Pohl and Bernd Schneider sought to answer two questions: 1. What role do the seasons play in the processes that cause mercury to be released by the oceans as a volatile gas? 2. What is the spatial distribution of mercury in the Atlantic Ocean?

Mercury is potentially harmful to both humans and animals. To understand its behavior in the environment is therefore of great societal interest. However, although the amount of mercury circulating in the environment has been tripled by human activities, broad-ranging and long-term research programs have yet to completely elucidate the steps comprising the mercury cycle.

Mercury is mainly emitted into the atmosphere and subsequently distributed worldwide as volatile elemental mercury. Within the atmosphere, mercury is slowly oxidized and then becomes bound to dust particles. Rainfall washes the dust together with the bound mercury out of the atmosphere, with subsequent transport of the heavy metal into the oceans. While many other such metals partially exit the cycle, sinking to the sea floor attached to particles, mercury can be converted back to the volatile elemental form by exposure to light, either with or without the involvement of algae. By this route, it escapes the oceans and is distributed further. The amount of mercury that is actually emitted is difficult to determine and to date only few measurement data have been available.

During two research cruises with the r/v Polarstern, traveling between the English Channel and South Africa and – half a year later – from southern South America to Germany, an intensive measuring campaign was undertaken to determine the concentration of volatile mercury both in the surface waters and in the atmosphere.

For the IOW researchers, it was astonishing to recognize that, in contrast to their expectations, most of the elemental mercury was not found in the industrialized temperate zone of the Northern hemisphere but in the tropical zone of the Atlantic Ocean.

According to Joachim Kuss and his colleagues, this fact can be explained by the underlying conditions, which strongly favor the production of volatile mercury. The tropical climate promotes the emission of mercury in a process made up of several successive steps.

Strong tropical rainfalls cause oxidized mercury to be washed out of the atmosphere into the ocean in a very effective manner. Afterwards, intense solar radiation converts the mercury into its volatile form, which in turn concentrates within the upper 20 m of the tropical Atlantic. However, mercury emission is not initiated until the winds become stronger. This task is fulfilled by the powerful trade winds once they pass over those regions of the sea in which the surface waters are enriched in mercury. Thus, year-round, the tropical Atlantic provides the optimum prerequisites allowing the escape of mercury.

The observations resulted in another new hypothesis: until now, researchers working on atmospheric models assumed that the seasonal emission of mercury from the oceans is caused by solar radiation and the activity of algae.

According to the new measurements, however, the presumed overall coupling to algal growth seems to be incorrect, as it would require very strong emissions coinciding with the peak of the bloom. But during the springtime bloom (April/May in the North Atlantic; November in the South Atlantic) no increase in mercury emissions was detected. Instead, high-level emissions were found to occur in autumn (November in the North Atlantic; April/May in the South Atlantic).

The comprehensive measurements performed by the IOW scientists were used to estimate annual global mercury emissions. According to these projections, two million kilograms of mercury are emitted annually by the global oceans. This nearly equals the total annual anthropogenic emissions and is in good accordance with theoretical predictions derived from atmospheric models. However, deviations are clearly evident with respect to the seasonal and spatial contributions of the processes. While the results of the Warnemünde researchers provide new insight in this context, further global measuring campaigns and local-process studies are required for a deeper understanding of the marine mercury cycle.

Contact:
Dr. Joachim Kuss, +49 381 / 5197 314
Department of Marine Chemistry, Leibniz Institute for Baltic Sea Research Warnemünde
oder
Dr. Barbara Hentzsch, +49 381 / 5197 102
Public relation officer, Leibniz Institute for Baltic Sea Research Warnemünde
The IOW is member of the Leibniz Association, a network of 87 scientifically, legally and economically independent research institutes and scientific service facilities. Leibniz Institutes perform strategic-and thematically-oriented research and offer scientific services of national significance while striving to provide scientific solutions to major social challenges.

The 16,800 employees of the Leibniz Institutes include 7,800 academics, with 3,300 junior scientists. One indication of the Leibniz Institutes' strong competitiveness and excellence is the 330 million Euros allocated to them from third-party funds. The total budget of all Leibniz Institutes amounts to more than 1.4 billion Euros.

Leibniz Institutes contribute to clusters of excellence in fields such as mathematics, optic technologies, materials research, medicine, climate and environmental research, and bio- and nanotechnology as well as the humanities, economics, and social sciences. They foster close co-operations with universities, industry, and other research institutes, both in Germany and abroad. The Leibniz Association has developed a comprehensive system of quality management in which, at regular intervals, independent experts assess every institute as part of the Association's unique peer review evaluation process.

www.leibniz-association.eu

Dr. Barbara Hentzsch | idw
Further information:
http://www.leibniz-association.eu

More articles from Life Sciences:

nachricht Discovery of a Key Regulatory Gene in Cardiac Valve Formation
24.05.2017 | Universität Basel

nachricht Carcinogenic soot particles from GDI engines
24.05.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

Physicists discover mechanism behind granular capillary effect

24.05.2017 | Physics and Astronomy

Measured for the first time: Direction of light waves changed by quantum effect

24.05.2017 | Physics and Astronomy

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>