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 Kidney tumor: Genetic trigger discovered
18.06.2018 | Julius-Maximilians-Universität Würzburg

nachricht New type of photosynthesis discovered
18.06.2018 | Imperial College London

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

Im Focus: Photoexcited graphene puzzle solved

A boost for graphene-based light detectors

Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...

Im Focus: Water is not the same as water

Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.

From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Novel method for investigating pore geometry in rocks

18.06.2018 | Earth Sciences

Diamond watch components

18.06.2018 | Process Engineering

New type of photosynthesis discovered

18.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>