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
How is climate change affecting fauna in the Arctic?
22.05.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
Sea level as a metronome of Earth's history
19.05.2017 | Université de Genève
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...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
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...
Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...
For the first time, scientists have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope. Researchers from the University of Basel’s Swiss Nanoscience Institute network have reported the results in the journal Science Advances.
Hydrogen is the most common element in the universe and is an integral part of almost all organic compounds. Molecules and sections of macromolecules are...
22.05.2017 | Event News
17.05.2017 | Event News
16.05.2017 | Event News
22.05.2017 | Materials Sciences
22.05.2017 | Life Sciences
22.05.2017 | Physics and Astronomy