Quantifying the Effect of Wind on Volcanic Plumes: Implications for Plume Modeling

Abstract

Explosive eruptions are characterized by the production of volcanic ash, which can be injected into the atmosphere by buoyant eruptive columns (e.g.,

New Insights Into the Relationship Between Mass Eruption Rate and Volcanic Column Height Based On the IVESPA Data Set

“…This value is considerably lower than that originally proposed in Bonadonna, Pistolesi, et al. (2015) for the 2011 Cordon Caulle eruption, Chile (Π ≈ 10) but is in agreement with Π = 0.5 as found in recent studies for Etna (Scollo et al., 2019) and Eyjafjallajökull (Dürig et al., 2023). Despite the absence of any clear relationship between $${\overline{H}}_{\mathrm{t}\mathrm{o}\mathrm{p}}^{\mathrm{s}\mathrm{t}\mathrm{d}}$$ and Π in Figure 2d, the statistically significant correlation hints to a small but discernible influence of the plume morphology on the $${\overline{H}}_{\mathrm{t}\mathrm{o}\mathrm{p}}$$–$$\overline{\mathrm{M}\mathrm{E}\mathrm{R}}$$ relationship.…”

“…Both types of plumes are found for 0.03 < Π < 0.35 (Figure 2d and Figure S3 in Supporting Information S1), suggesting a transition from weak to strong plumes at a critical value of Π ≈ 0.1. This value is considerably lower than that originally proposed in for the 2011 Cordon Caulle eruption, Chile (Π ≈ 10) but is in agreement with Π = 0.5 as found in recent studies for Etna (Scollo et al, 2019) and Eyjafjallajökull (Dürig et al, 2023). Despite the absence of any clear relationship between 𝐴𝐴 𝐻𝐻 std top and Π in Figure 2d, the statistically significant correlation hints to a small but discernible influence of the plume morphology on the 𝐴𝐴 𝐻𝐻top -𝐴𝐴 MER relationship.…”

“…This parameter is constrained using direct observations (e.g., pictures, infrared cameras) for only 44 events in IVESPA, so we complement it by calculating $$${\Pi }={\left(\frac{\alpha }{\beta }\right)}^{2}\frac{{\overline{H}}_{\mathrm{t}\mathrm{o}\mathrm{p}}\,\overline{N}}{1.8\,\overline{W}}$$$ for each event. Π is a non‐dimensional parameter defined by the ratio of the wind entrainment and plume rise timescales (Degruyter & Bonadonna, 2012) and has been shown to relate to the plume morphology for a handful of eruptions (e.g., Bonadonna, Pistolesi, et al., 2015; Dürig et al., 2023; Scollo et al., 2019). We use α = 0.1 and β = 0.5 in Equation , consistent with latest entrainment coefficient estimates (e.g., Aubry & Jellinek, 2018; Michaud‐Dubuy et al., 2020).…”

“…for each event. Π is a non-dimensional parameter defined by the ratio of the wind entrainment and plume rise timescales (Degruyter & Bonadonna, 2012) and has been shown to relate to the plume morphology for a handful of eruptions (e.g., Dürig et al, 2023;Scollo et al, 2019). We use α = 0.1 and β = 0.5 in Equation 3, consistent with latest entrainment coefficient estimates (e.g., Aubry & Jellinek, 2018;Michaud-Dubuy et al, 2020).…”

Using Simulated Radiances to Understand the Limitations of Satellite-Retrieved Volcanic Ash Data and the Implications for Volcanic Ash Cloud Forecasting

“…We consider three different solutions: (Hmin, MERmin), (Havg, MERavg), (Hmax, MERmax), as outlined in Dioguardi et al (2020). REFIR allows assigning different weights to the six models, and the fine tuning of wind entrainment coefficients (Dürig et al, 2023a(Dürig et al, , 2023b. In this study each model was equally-weighted, and the wind entrainment coefficient for Degruyter and Bonadonna (2012) was set to the default value of 0.5.…”