To support the safety of air transport and improve the air traffic system's response times in the critical event of a volcanic eruption, the identification of ash-free airspace is essential. At the DLR Institute of Atmospheric Physics, a satellite-supported procedure has been developed that rapidly determines the distribution of ash in the air and generates detailed images of areas with both heavy and light ash loads.
The eruption of the Icelandic volcanoes Eyjafjallajökull in 2010 and Grímsvötn in 2011 demonstrated the vulnerability of the air traffic system in the event of volcanic eruptions and exposed gaps in the observation systems for volcanic ash. Because of this, it was decided to develop a process to precisely track ash clouds using satellites that are already in space. In April 2010, large areas of the airspace over Europe had to be shut down as there were no threshold values available for tolerable concentrations of ash at the beginning of the crisis, and the actual concentration of ash in the air was not fully understood. At the time, approximately 100,000 flights were cancelled.
After the Eyjafjallajökull eruption, a threshold value of two to four milligrams of ash per cubic meter was determined as the maximum volcanic ash concentration permitted for aircraft to fly through the airspace above central Europe and Great Britain. By 2015, the scientists want to be capable of measuring the ash cloud from a volcanic eruption in a timely and precise manner, and predict its movement during the following hours. Satellite data is the most important source of information for making large-scale assessments of how an ash cloud is spreading. Scientists at the DLR Institute of Atmospheric Physics have been working on the evaluation of Meteosat data for detecting volcanic ash since 2012, under the project VOLCATS (VOLCanic Ash impact on the air Transport System). In doing so, important infrared signatures for volcanic ash in the airspace have been detected and integrated into the data evaluation. To achieve this, repeated comparison measurements were carried out by the DLR Falcon research aircraft in the vicinity of volcanoes and in mineral dust clouds, which the researchers used as test scenarios.
A prototype of the new procedure for satellite-based volcanic ash detection (VADUGS - Volcanic Ash Detection Utilizing Geostationary Satellites) is ready for its first deployment in the event of an ash cloud resulting from the Bárðarbunga volcano eruption. Not only will it provide significantly more accurate information about where the ash cloud is spreading to and in what concentration, but this information will also be kept fully updated. Every 15 minutes, the second generation Meteosat satellites operated by EUMETSAT will be providing data for an updated view of the situation.
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DLR press release