Operational Response to Volcanic Ash Risks Using HOTVOLC Satellite-Based System and MOCAGE-Accident Model at the Toulouse VAAC

Philippe Hereil,Mathieu Deslandes,Mathieu Gouhier,Philippe Cacault,Béatrice Josse,Yannick Guéhenneux

doi:10.3390/atmos11080864

Abstract

In 2010, the Eyjafjallajökull volcano erupted, generating an ash cloud causing unprecedented disruption of European airspace. Despite an exceptional situation, both the London and Toulouse Volcanic Ash Advisory Centres (VAAC) provided critical information on the location of the cloud and on the concentration of ash, thus contributing to the crisis management. Since then, substantial efforts have been carried out by the scientific community in order to improve remote sensing techniques and numerical modeling. Satellite instruments have proven to be particularly relevant for the characterization of ash cloud properties and a great help in the operational management of volcanic risk. In this study, we present the satellite-based system HOTVOLC developed at the Observatoire de Physique du Globe de Clermont-Ferrand (OPGC) using Meteosat geostationary satellite and designed for real-time monitoring of active volcanoes. After a brief presentation of the system we provide details on newly developed satellite products dedicated to the ash cloud characterization. This includes, in particular, ash cloud altitude and vertical column densities (VCD). Then, from the Stromboli 2018 paroxysm, we show how HOTVOLC can be used in a timely manner to assist the Toulouse VAAC in the operational management of the eruptive crisis. In the second part of the study, we provide parametric tests of the MOCAGE-Accident model run by the Toulouse VAAC from the April 17 Eyjafjallajökull eruption. For this purpose, we tested a range of eruption source parameters including the Total Grain Size Distribution (TGSD), the eruptive column profile, the top plume height and mass eruption rate (MER), as well as the fine ash partitioning. Finally, we make a comparison on this case study between HOTVOLC and MOCAGE-Accident VCD.

Highlights

Today, operational monitoring of volcanic ash in the atmosphere is achieved through both in-situ and remote sensing methods [1]
This is the case for Mount St-Helens (USA) on 18 May 1980, tracked by the American geostationary satellite GOES [5] or more recently, during the 2010 Eyjafjallajökull eruption (Iceland) using the European geostationary satellite METEOSAT [6]
In this study we present how satellite-based data from the HOTVOLC system developed at OPGC (Observatoire de Physique du Globe de Clermont-Ferrand, France) can be used in combination with the MOCAGE-Accident (Modèle de Chimie Atmosphérique de Grande Echelle) model, designed by Météo-France, [17] for the mitigation of risks associated with volcanic ash clouds

Summary

Introduction

Operational monitoring of volcanic ash in the atmosphere is achieved through both in-situ and remote sensing methods [1]. Since the 1980s, the use of GEO satellite has led to a significant improvement in the detection and monitoring of volcanic ash plumes This is the case for Mount St-Helens (USA) on 18 May 1980, tracked by the American geostationary satellite GOES [5] or more recently, during the 2010 Eyjafjallajökull eruption (Iceland) using the European geostationary satellite METEOSAT [6]. From the onset of an eruption, strong plumes reach the tropopause (11–16 km a.s.l.) in a few tens of minutes only, and can be transported for days over thousands of kilometres away in the atmosphere [8] In this regard, the high temporal resolution of GEO platforms represents a valuable tool for the rapid assessment of volcanic ash risk [9]. This allows us to compare vertical column densities from both MOCAGE-Accident and HOTVOLC for the same eruption

HOTVOLC Ash Product Definition

Ash cloud UTC detected the HOTVOLC using of theSO

Conclusions