First results of an airborne release of volcanic ash for testing of volcanic ash plume measurement instruments

Kurzfassung

The eruption of the Icelandic volcanoes Eyjafjallajökull 2010 and Grimsvötn 2011 caused significant disruptions of the air traffic over Europe. The airspace of nearly whole Europe was closed for about a week in spring 2010 during the eruption of the Eyjafjallajökull. This caused an economic damage of several billion Euros. About one year later, in spring 2011, the Grimsvötn volcano erupted on Iceland. Because of this eruption the airports of many countries in North Europe were closed and caused therefore problems for the international air traffic as well. At the time of the Eyjafjallajökull eruption the decision of the legal authorities about the airspace closure were mainly based on the volcanic ash plume predictions of the Volcanic Ash Advisory Center (VAAC) in UK, which were gained by a numerical ash dispersion model. However, as it turned out later on, evidently the VAAC ash dispersion model could not always predict the dispersion of the ash plume precisely. Therfore the decision was taken to add so-called second sources of information like groundbased and airborne measurements of the volcanic ash plume as well as satellite observations for getting a more precise picture of the ash plume spread and concentration. However, at that point the question arises, how the accuracy of these measurement methods can be assured. Therefore in this paper a procedure is described for the production of an artificial ash plume, which is released from an aircraft. This ash plume simulates on a small scale the real world ash plume of a volcanic eruption. By these means systems for the measurement of ash can be tested and calibrated in a new and innovative way.