Monitoring presence and streaming patterns of Icelandic volcanic ash during its arrival to Slovenia

The eruption of the Eyjafjallajökull volcano starting on 14 April 2010 resulted in the spreading of volcanic ash over most parts of Europe. In Slovenia, the presence of volcanic ash was monitored using ground-based in-situ measurements, lidar-based remote sensing and airborne in-situ measurements. Volcanic origin of the detected aerosols was confirmed by subsequent spectral and chemical analysis of the collected samples. The initial arrival of volcanic ash to Slovenia was detected at ground level using in-situ measurements during the night of 17 April 2010, but was not observed via lidar-based remote sensing due to the presence of clouds at lower altitudes while the streaming height of ash-loaded air masses was above 5 km a.s.l. The second arrival of volcanic ash on 20 April 2010 was detected by both lidar-based remote sensing and airborne in-situ measurement, revealing two or more elevated atmospheric aerosol layers above Slovenia. Identification of samples from ground-based in-situ and airborne in-situ measurements based on energy-dispersive X-ray spectroscopy confirmed that a fraction of particles was volcanic ash from the Eyjafjallajökull eruption. We performed simulations of airflow trajectories to explain the arrival of the air masses containing volcanic ash to Slovenia