Monitoring ash events from space combining polar and geostationary satellite observations: recent results from RSTASH algorithm

Several studies have demonstrated the capacity of RST_ASH, which is a specific configuration of the RST (Robust Satellite Technique) multi-temporal approach, in detecting and tracking ash clouds from space under different atmospheric and observational conditions using both polar and geostationary satellite data. RST_ASH has been implemented within an automated processing chain developed at IMAA (Institute of Methodologies for Environmental Analysis) to perform the near-real time monitoring of ash clouds emitted by Italian volcanoes like Mt. Etna, exploiting AVHRR (Advanced Very-High-Resolution Radiometer) and MODIS (Moderate Resolution Imaging Spectroradiometer) observations. Recently, an optimized configuration of RST_ASH tailored to SEVIRI data has been developed and tested in the framework of the EU H2020 project EUNADICS-AV (European Natural Airborne Disaster Information and Coordination System for Aviation) to further increase discrimination capabilities of ash from meteorological clouds. In this work, we present some results of these analyses, including the validation of RST_ASH detections at a local scale, using information provided by the EARLINET (European Aerosol Research Lidar Network) network. In addition, outcomes achieved investigating recent eruptions from Mt. Agung and Sinabung (Indonesia) eruptions exploiting high-temporal resolution (10 min) Himawari-8 data are also shown and discussed. The latter confirm RST_ASH as a suitable tool in supporting the operational monitoring of ash events at a global scale.