Since the eruption of Iceland´s volcanoes Eyjafjallajökull and the Grimsvötn, as well as now of Chile´s Puyehue-El Caulle, the volcanic ash causes severe disturbances within the international aviation. Predictions regarding the dispersion of the volcanic ash and estimations of the risk potential for airplanes are based upon simulated calculations by the Volcanic Ash Advisory Centers (VACC).
Another possibility to learn more about volcanic ash, is to measure the volcanic ash directly in the atmosphere. Therefore LIDAR (Light Detection and Ranging) instruments are used on the ground or inside air planes. With this method, emitted laser pulses reflect from the ash particles and those scattering signals are then collected by a telescope. Such data however, gives no direct information on the concentration and size of ash particles. In order to measure particles directly within the volcanic ash, we equip air planes with special laser aerosol-spectrometers, such as GRIMM´s Sky-OPC. In collaboration with the German Aerospace Center (DLR), Grimm Aerosol Technik developed for many years such devices. The Sky-OPC is able to detect the particle concentration and the particle size of ash particles ranging from 250 nm up to 32 µm. This laser aerosolspectrometer can be operated in altitudes of 10 km (33000 ft.) and even higher! Currently this device is used in Germany, Great Britain, Norway, and Iceland.
Even more laser aerosol-spectrometers by Grimm Aerosol Technik are able to measure volcanic ash inside airplanes up to altitudes of 2 – 3 km. These devices are very compact, light, and battery-operated. Thus they perfectly suit for the operation inside microlights, or smaller airplanes without the need of scientific staff on board. Such kind of measurements are presently done in Austria, Germany, and Switzerland.
For over ten years now, we at Grimm Aerosol Technik operate laser aerosol-spectrometers inside airplanes for measuring airborne particles. First experiences and measurement data were collected for example at the Lindenberger Aerosol Characterisation Experiment (LACE 98) in 1998. Here the main focus was on ash particles emitted by a forest fire in Canada also a veritable source of fine particles worldwide.
More information on airplane measurements and volcanic ash:
http://mv.fh-duesseldorf.de/d_pers/Weber_Konradin
http://www.atmos-chem-phys.org/11/2245/2011/acp-11-2245-2011.html
http://www.dlr.de/desktopdefault.aspx/tabid-6449/10620_read-23839/
http://www.rocketrange.no/?page_id=21
Copyright: Grimm Aerosol Technik 2011