Model-based aviation advice on distal volcanic ash clouds by assimilating aircraft in situ measurements
- 1Delft University of Technology, Delft Institute of Applied Mathematics, Mekelweg 4, 2628 CD Delft, the Netherlands
- 2TNO, Department of Climate, Air and Sustainability, P.O. Box 80015, 3508 TA Utrecht, the Netherlands
- 3University of Applied Sciences, Environmental Measurement Techniques, Josef-Gockeln-Str. 9, 40474 Düsseldorf, Germany
Abstract. The forecast accuracy of distal volcanic ash clouds is important for providing valid aviation advice during volcanic ash eruption. However, because the distal part of volcanic ash plume is far from the volcano, the influence of eruption information on this part becomes rather indirect and uncertain, resulting in inaccurate volcanic ash forecasts in these distal areas. In our approach, we use real-life aircraft in situ observations, measured in the northwestern part of Germany during the 2010 Eyjafjallajökull eruption, in an ensemble-based data assimilation system combined with a volcanic ash transport model to investigate the potential improvement on the forecast accuracy with regard to the distal volcanic ash plume. We show that the error of the analyzed volcanic ash state can be significantly reduced through assimilating real-life in situ measurements. After a continuous assimilation, it is shown that the aviation advice for Germany, the Netherlands and Luxembourg can be significantly improved. We suggest that with suitable aircrafts measuring once per day across the distal volcanic ash plume, the description and prediction of volcanic ash clouds in these areas can be greatly improved.