Modelling the volcanic ash plume from Eyjafjallajökull eruption (May 2010) over Europe: evaluation of the benefit of source term improvements and of the assimilation of aerosol measurements

Abstract

Abstract. Numerical dispersion models are used operationally worldwide to mitigate the effect of volcanic ash on aviation. In order to improve the representation of the horizontal dispersion of ash plumes and of the 3D concentration of ash, a study was conducted using the MOCAGE model during the EUNADICS-AV project. Source term modelling and assimilation of different data were investigated. A sensitivity study to source term formulation showed that a resolved source term, using the FPLUME plume-rise model in MOCAGE, instead of a parameterised source term, induces a more realistic representation of the horizontal dispersion of the ash plume. The FPLUME simulation provides more concentrated and focused ash concentrations in the horizontal and the vertical dimensions than the other source term. The assimilation of MODIS Aerosol Optical Depth has an impact on the horizontal dispersion the plume, but this effect is rather low and local, compared to source term improvement. More promising results are obtained with the continuous assimilation of ground-based lidar profiles, which improves the vertical distribution of ash and helps to reach realistic values of ash concentrations. The improvement can remain several hours after and several hundred kilometers away downstream to the assimilated profiles.

The New Volcanic Ash Satellite Retrieval VACOS Using MSG/SEVIRI and Artificial Neural Networks: 2. Validation

“…To expand on this idea, further processing of the retrieval map seems desirable, e.g., to cluster ash-containing pixels and quantify the resulting ash patches, or even track them in time. Possible fields of application of VACOS include the Volcanic Ash Advisory Centers, the intercomparison with other volcanic ash retrievals (as in [46]), calibrating and validating volcanic ash transport and dispersion models [35,[47][48][49] and flight planning for future in situ measurements [15]. Due to the high spatial and temporal resolution, it can be used to track individual ash clouds to investigate their lifecycle on timespans of days to weeks.…”

Online treatment of eruption dynamics improves the volcanic ash and SO<sub>2</sub> dispersion forecast: case of the 2019 Raikoke eruption

“…Another example is the study by Collini et al (2013), who combined the WRF-ARW (Weather Research and Forecasting-Advanced Research WRF) forecast system with FALL3D and highlighted a good agreement in ash transport simulations with satellite observations for the 2011 Cordón Caulle eruption. Plu et al (2021) simulated the 2010 Eyjafjallajökull eruption with the MOCAGE model (Modèle de Chimie Atmosphérique de Grande Echelle) and hourly changing MER from FPlume. They highlighted more concentrated ash concentrations in the horizontal and vertical scale, which more realistically represents the horizontal dispersion compared to parameterized MERs.…”

Effects of Variable Eruption Source Parameters on Volcanic Plume Transport: Example of the 23 November 2013 Paroxysm of Etna

“…Likely, the Eyjafjallajökull eruption (15 April 2010) is the most studied recent event due to its strong impact on air traffic and economy in Europe. In this context, Plu et al [25] simulated this eruption with the MOCAGE-CTM (Météo-France) and hourly changing MER from FPlume [6]. For the same eruption, Devenish et al [26] and Webster et al [27] both used the lagrangian model NAME while Folch et al [28] used the FALL3D model.…”