One year after the Eyjafjallajökull volcano in Iceland brought European air traffic to a standstill its ash plume revealed a surprising scientific finding: Researchers at the Max Planck Institute for Chemistry in Mainz found that the ash plume contained not only the common volcanic gas sulfur dioxide, but also free chlorine radicals.
CARIBIC flight track from Frankfurt to the British Isles on May 16. The dots indicate air sampling locations. The colored regions depict the extent of the volcanic ash cloud as calculated using meteorological models, with red/yellow indicating high and purple low amounts of particles. Figure taken from Baker et al., 2011 (GRL).
Chlorine radicals are extremely reactive and even small amounts can have a profound impact on local atmospheric chemistry. The findings, which will be published in “Geophysical Research Letters“ give solid evidence of volcanic plume chlorine radical chemistry and allowed calculations of chlorine radical concentrations.
It has been known for some time that volcanic eruptions emit chlorine-containing gases, causing scientists to suspect that highly reactive chlorine radicals could also be present. However, sufficient experimental evidence proved elusive. That changed when researchers analyzed air collected in the ash cloud emitted by the Eyjafjallajökull volcano. During three special flights conducted by Lufthansa in spring 2010 using the CARIBIC atmospheric measurement container, researchers collected air samples which they brought back to their laboratory in Mainz for analysis. Among the compounds they looked for were hydrocarbons.
”Each volcano has its own character”, says Angela Baker, lead author of the paper. “We found that hydrocarbon concentrations were up to 70% lower inside the Eyjafjallajökull ash cloud than outside. Reaction with chlorine radicals was the only realistic explanation for the hydrocarbon losses. And further investigation confirmed that free chlorine radicals were the cause“. The scientists calculated concentrations of up to 66,000 chlorine atoms per cubic centimeter of air. While modest compared to concentrations of other gases, chlorine radicals are normally absent, and it does not take much of these very reactive atoms to have a noticeable impact on atmospheric chemistry.
Hydrocarbons like propane and butane can be found even in the cleanest and most remote parts of the lower atmosphere. Normally they are removed when they react with hydroxyl radicals, but they react many times faster with chlorine radicals. In doing so the chlorine reactions leave their specific ”signature“ on the mixture of hydrocarbons in the air. This signature can, in turn, be used to calculate how many chlorine radicals were present. The Max Planck scientists who calculated volcanic ash cloud chlorine radical concentrations for the first time anticipate that similar results will be found in plumes from other volcanoes, such as the currently erupting Grimsvötn. They also hope that their method will be used during future studies to identify and understand volcanic chlorine radical chemistry.About the CARIBIC measurement container
Outside air containing trace gases and aerosol particles is collected during the entire flight by a dedicated inlet probe underneath the aircraft’s hull and fed into the measurement equipment inside the container. The container was deployed during three special flights to probe parts of the volcanic plume of the Eyjafjallyjökull on Iceland that erupted in April and May 2010.
The equipment in the container detects over 50 different atmospheric species, including greenhouse gases, ozone, CFCs, water vapor and aerosols. The detailed dataset helps to locate sources of air pollution, to find out how air pollution is transported and how the atmosphere cleans itself. In this way, by using in-service passenger aircraft one can obtain a precise picture of the atmosphere’s composition and processes at reasonable cost. CARIBIC is enabled by Lufthansa and sponsored by Frankfurt Airport since 2009.
For further information about the measurement container and the project, please visit http://www.caribic-atmospheric.comAbout the Max Planck Institute for Chemistry
Geophysical Research Letters, in press, 2011Contact:
Further reports about: > CARIBIC > CHEMISTRY > Cloud Computing > Earth's magnetic field > Eyjafjallajökull > Geophysical Research > Geophysical Research Letters > Iceland > Icelandic volcanoes > ash plume > atmospheric chemistry > chlorine > greenhouse gas > natural resource > volcanic > volcanic plume
Multi-year submarine-canyon study challenges textbook theories about turbidity currents
12.12.2017 | Monterey Bay Aquarium Research Institute
How do megacities impact coastal seas? Searching for evidence in Chinese marginal seas
11.12.2017 | Leibniz-Institut für Ostseeforschung Warnemünde
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
14.12.2017 | Health and Medicine
14.12.2017 | Physics and Astronomy
14.12.2017 | Life Sciences