Surveying the Skies: Scientists Call For Volcanic Dust Measurement Network
Europe is ill-prepared for volcanic eruptions such as that of Eyjafjallajökull on Iceland which brought the continent's air traffic to a near-standstill. Now researchers are calling for a Europe-wide aerosol measurement network to be set up, so that volanic dust in the air can be accurately studied.
When the Eyjafjallajökull volcano erupted last week in Iceland, it did not only paralyze most of Europe's airspace. It also revealed weaknesses in the current state of atmospheric observation in Germany.
It was initially difficult to take measurements of the cloud of volcanic dust over the country, which caused airspace in Germany and several European countries to be closed. "We were obviously caught sleeping," complained the spokesman for the German pilots' union Cockpit, Jörg Handwerg, who added that Germany was "poorly positioned" in regard to measurement capability.
Researchers were quick to defend themselves against accusations that they had been too slow in collecting data. But one thing seems clear: The existing technical facilities for investigating the ash cloud left something to be desired. For example, although the German Weather Service (DWD) has 35 to 40 so-called ceilometers, instruments which are used to determine the height of a cloud base, they are not able to map the location of the volcanic ash cloud precisely.
"Our laser measuring devices are currently not suitable for that purpose," DWD spokesman Gerhard Lux told SPIEGEL ONLINE in an interview. A lot of interpretation work is needed just to be able to detect the ash cloud within the data, he explained. The DWD was only able to indirectly detect the ash by sending up weather balloons from the Hohenpeissenberg meteorological observation station near Munich.
German atmospheric researchers are now calling for a permanent early-warning network to be set up. They also complain that a previous attempt to establish such a network failed due to lack of money.
Hartmut Grassl of the Hamburg-based Max Planck Institute for Meteorology points out that there used to be a Europe-wide measurement network for aerosols -- in other words, very fine particles in the air -- known as EARLINET (European Aerosol Research Lidar Network). But the network has since been partially shut down due to a lack of funding, he said, although some laser measuring devices -- such as the one in Hamburg -- continue to operate. One major problem is that there is no longer any centralized collection of data. "Coordination is the decisive point," Grassl said. "Such networks need to go into routine operation. And if you want to have continuity, then the weather service has to take control over them."
Under the current system, it is not possible to easily collate individual observations of the volcanic cloud. Measurement methods, observation periods and data format all vary from institute to institute -- a fact that may also complicate the predictions produced by the Volcanic Ash Advisory Center (VAAC) at the British Met Office in London.
European flight safety authorities are basing their decisions to close airspaces on data provided by the VAAC. Some observers, including European officials, have been critical of the methods used by the center to produce its forecasts, claiming they may have overstated the risk to the public.
Cutbacks in the Wrong Places
But is it really worth setting up a permanent monitoring network just to help mitigate the effects of the occasional volcanic eruption? Atmospheric researchers argue that it is, explaining that there are many other areas which could also be investigated with such a network. These fields include studying dust from the Sahara, which fertilizes Europe's seas with iron and causes algae blooms, aerosol clouds from huge forest fires and everyday air pollution.
Atmospheric researcher Volker Wulfmeyer of the University of Hohenheim also argues in favor of an aerosol measurement network in continuous operation. He feels it should be run by the German Weather Service. So far, he says, the DWD only has a few well-equipped stations. The weather service was forced to make cutbacks "in the wrong places," Wulfmeyer says. "That should be reconsidered in light of the current circumstances."
Researcher Joachim Curtius of the Johann Wolfgang Goethe University in Frankfurt has another suggestion. "In the longer term, it might be worthwhile to also equip commercial aircraft with particle-measuring instruments," he says. The instruments could then warn pilots and advise them to fly at a different altitude, he explains. According to the scientist, the instruments currently cost tens of thousands of euros each, because they are only produced in small quantities for research purposes.
Nevertheless, airlines should still consider buying the devices, he argues. "Given the high losses caused by the interruption of air traffic, the investment could certainly pay off for airlines," Curtius says. "Especially if the volcano is active for a year or longer."
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