Reconstructing volcanic plume evolution integrating satellite and ground-based data: application to the 23 November 2013 Etna eruption

Abstract. Recent explosive volcanic eruptions recorded worldwide (e.g. Hekla in 2000, Eyjafjallajökull in 2010, Cordón-Caulle in 2011) demonstrated the necessity for a better assessment of the eruption source parameters (ESPs; e.g. column height, mass eruption rate, eruption duration, and total grain-size distribution – TGSD) to reduce the uncertainties associated with the far-travelling airborne ash mass. Volcanological studies started to integrate observations to use more realistic numerical inputs, crucial for taking robust volcanic risk mitigation actions. On 23 November 2013, Etna (Italy) erupted, producing a 10 km height plume, from which two volcanic clouds were observed at different altitudes from satellites (SEVIRI, MODIS). One was retrieved as mainly composed of very fine ash (i.e. PM20), and the second one as made of ice/SO2 droplets (i.e. not measurable in terms of ash mass). An atypical north-easterly wind direction transported the tephra from Etna towards the Calabria and Apulia regions (southern Italy), permitting tephra sampling in proximal (i.e. ∼ 5–25 km from the source) and medial areas (i.e. the Calabria region, ∼ 160 km). A primary TGSD was derived from the field measurement analysis, but the paucity of data (especially related to the fine ash fraction) prevented it from being entirely representative of the initial magma fragmentation. To better constrain the TGSD assessment, we also estimated the distribution from the X-band weather radar data. We integrated the field and radar-derived TGSDs by inverting the relative weighting averages to best fit the tephra loading measurements. The resulting TGSD is used as input for the FALL3D tephra dispersal model to reconstruct the whole tephra loading. Furthermore, we empirically modified the integrated TGSD by enriching the PM20 classes until the numerical results were able to reproduce the airborne ash mass retrieved from satellite data. The resulting TGSD is inverted by best-fitting the field, ground-based, and satellite-based measurements. The results indicate a total erupted mass of 1.2  ×  109 kg, being similar to the field-derived value of 1.3  ×  109 kg, and an initial PM20 fraction between 3.6 and 9.0 wt %, constituting the tail of the TGSD.

Download Full-text

FPLUME-1.0: An integral volcanic plume model accounting for ash aggregation

Geoscientific Model Development ◽

10.5194/gmd-9-431-2016 ◽

2016 ◽

Vol 9 (1) ◽

pp. 431-450 ◽

Cited By ~ 35

Author(s):

A. Folch ◽

A. Costa ◽

G. Macedonio

Keyword(s):

Grain Size ◽

Size Distribution ◽

Grain Size Distribution ◽

Risk Mitigation ◽

Source Parameters ◽

Air Entrainment ◽

Phase Changes ◽

Column Height ◽

Volcanic Plume ◽

Eruption Column

Abstract. Eruption source parameters (ESP) characterizing volcanic eruption plumes are crucial inputs for atmospheric tephra dispersal models, used for hazard assessment and risk mitigation. We present FPLUME-1.0, a steady-state 1-D (one-dimensional) cross-section-averaged eruption column model based on the buoyant plume theory (BPT). The model accounts for plume bending by wind, entrainment of ambient moisture, effects of water phase changes, particle fallout and re-entrainment, a new parameterization for the air entrainment coefficients and a model for wet aggregation of ash particles in the presence of liquid water or ice. In the occurrence of wet aggregation, the model predicts an effective grain size distribution depleted in fines with respect to that erupted at the vent. Given a wind profile, the model can be used to determine the column height from the eruption mass flow rate or vice versa. The ultimate goal is to improve ash cloud dispersal forecasts by better constraining the ESP (column height, eruption rate and vertical distribution of mass) and the effective particle grain size distribution resulting from eventual wet aggregation within the plume. As test cases we apply the model to the eruptive phase-B of the 4 April 1982 El Chichón volcano eruption (México) and the 6 May 2010 Eyjafjallajökull eruption phase (Iceland). The modular structure of the code facilitates the implementation in the future code versions of more quantitative ash aggregation parameterization as further observations and experiment data will be available for better constraining ash aggregation processes.

Download Full-text

FPLUME-1.0: An integrated volcanic plume model accounting for ash aggregation

Geoscientific Model Development Discussions ◽

10.5194/gmdd-8-8009-2015 ◽

2015 ◽

Vol 8 (9) ◽

pp. 8009-8062 ◽

Cited By ~ 2

Author(s):

A. Folch ◽

A. Costa ◽

G. Macedonio

Keyword(s):

Grain Size ◽

Size Distribution ◽

Grain Size Distribution ◽

Risk Mitigation ◽

Source Parameters ◽

Air Entrainment ◽

Phase Changes ◽

Column Height ◽

Volcanic Plume ◽

Eruption Column

Abstract. Eruption Source Parameters (ESP) characterizing volcanic eruption plumes are crucial inputs for atmospheric tephra dispersal models, used for hazard assessment and risk mitigation. We present FPLUME-1.0, a steady-state 1-D cross-section averaged eruption column model based on the Buoyant Plume Theory (BPT). The model accounts for plume bent over by wind, entrainment of ambient moisture, effects of water phase changes, particle fallout and re-entrainment, a new parameterization for the air entrainment coefficients and a model for wet aggregation of ash particles in presence of liquid water or ice. In the occurrence of wet aggregation, the model predicts an "effective" grain size distribution depleted in fines with respect to that erupted at the vent. Given a wind profile, the model can be used to determine the column height from the eruption mass flow rate or vice-versa. The ultimate goal is to improve ash cloud dispersal forecasts by better constraining the ESP (column height, eruption rate and vertical distribution of mass) and the "effective" particle grain size distribution resulting from eventual wet aggregation within the plume. As test cases we apply the model to the eruptive phase-B of the 4 April 1982 El Chichón volcano eruption (México) and the 6 May 2010 Eyjafjallajökull eruption phase (Iceland).

Download Full-text

Reconstructing volcanic plume evolution integrating satellite and ground-based data: Application to the 23rd November 2013 Etna eruption

10.5194/acp-2017-1146 ◽

2018 ◽

Cited By ~ 2

Author(s):

Matthieu Poret ◽

Stefano Corradini ◽

Luca Merucci ◽

Antonio Costa ◽

Daniele Andronico ◽

...

Keyword(s):

Grain Size ◽

Field Data ◽

Risk Mitigation ◽

Source Parameters ◽

Column Height ◽

Volcanic Plume ◽

Size Spectrum ◽

Data Application ◽

X Band ◽

Field Data Analysis

Abstract. Recent explosive eruptions recorded from different volcanoes worldwide (e.g. Hekla in 2000, Eyjafjallajökull in 2010, Cordón-Caulle in 2011) demonstrated the necessity of a better assessment of the eruption source parameters (e.g. column height, mass eruption rate and especially the Total Grain-Size Distribution – TGSD) to reduce the uncertainties associated with the far-travelling airborne ash mass. To do so, volcanological studies started to integrate observations in order to use more realistic numerical inputs, crucial for taking robust volcanic risk mitigation actions. On 23rd November 2013, Etna volcano (Italy) erupted producing a 10-km height plume, from which two volcanic clouds were observed at two different altitudes from satellite (MSG-SEVIRI, MODIS). One was described as mainly composed by very fine ash (i.e. PM20), whereas the second one as made of ice/SO2 droplets (i.e. not measurable in terms of ash mass). Atypical north-easterly winds transported the tephra from Etna towards the Puglia region (southern Italy), permitting tephra sampling in proximal (i.e. ~ 5–25–km from source) and medial areas (i.e. Calabria region, ~ 160 km). Based on the field data analysis, we estimated the TGSD but the paucity of data (especially related to the fine ash fraction) prevented it from being entirely representative of the initial magma fragmentation. To better estimate the TGSD covering the entire grain-size spectrum, we integrated the available field data with X-band weather radar and satellite retrievals. The resulting TGSD is used as input for the FALL3D tephra dispersal numerical model to reconstruct the tephra loading and the far-travelling airborne ash mass. The optimal TGSD is selected by solving an inverse problem through a best-fit with the field, ground-based and satellite-based measurements. The results suggest a total erupted mass of 1.2 × 109 kg, which is very similar to the field-derived value of 1.3 × 109 kg, and a TGSD with a PM20 fraction between 3.6 and 9.0 wt%.

Download Full-text

Interpretation of observed microwave signatures from ground dual polarization radar and space multi frequency radiometer for the 2011 Grímsvötn volcanic eruption

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-6-6215-2013 ◽

2013 ◽

Vol 6 (4) ◽

pp. 6215-6248 ◽

Cited By ~ 2

Author(s):

M. Montopoli ◽

G. Vulpiani ◽

D. Cimini ◽

E. Picciotti ◽

F. S. Marzano

Keyword(s):

Spatial Resolution ◽

Volcanic Ash ◽

Volcanic Eruptions ◽

Radar Data ◽

Radar Signal ◽

Volcanic Plume ◽

Dual Polarization ◽

X Band ◽

Volcanic Vent ◽

Ash Cloud

Abstract. The important role played by ground-based microwave weather radars for the monitoring of volcanic ash clouds has been recently demonstrated. The potential of microwaves from satellite passive and ground-based active sensors to estimate near-source volcanic ash cloud parameters has been also proposed, though with little investigation of their synergy and the role of the radar polarimetry. The goal of this work is to show the potentiality and drawbacks of the X-band Dual Polarization radar measurements (DPX) through the data acquired during the latest Grímsvötn volcanic eruptions that took place on May 2011 in Iceland. The analysis is enriched by the comparison between DPX data and the observations from the satellite Special Sensor Microwave Imager/Sounder (SSMIS) and a C-band Single Polarization (SPC) radar. SPC, DPX, and SSMIS instruments cover a large range of the microwaves spectrum, operating respectively at 5.4, 3.2, and 0.16–1.6 cm wavelengths. The multi-source comparison is made in terms of Total Columnar Concentration (TCC). The latter is estimated from radar observables using the "Volcanic Ash Radar Retrieval for dual-Polarization X band systems" (VARR-PX) algorithm and from SSMIS brightness temperature (BT) using a linear BT–TCC relationship. The BT–TCC relationship has been compared with the analogous relation derived from SSMIS and SPC radar data for the same case study. Differences between these two linear regression curves are mainly attributed to an incomplete observation of the vertical extension of the ash cloud, a coarser spatial resolution and a more pronounced non-uniform beam filling effect of SPC measurements (260 km far from the volcanic vent) with respect to the DPX (70 km from the volcanic vent). Results show that high-spatial-resolution DPX radar data identify an evident volcanic plume signature, even though the interpretation of the polarimetric variables and the related retrievals is not always straightforward, likely due to the possible formation of ash and ice particle aggregates and the radar signal depolarization induced by turbulence effects. The correlation of the estimated TCCs derived from DPX and SSMIS BTs reaches −0.73.

Download Full-text

The radius of the umbrella cloud helps characterize large explosive volcanic eruptions

Communications Earth & Environment ◽

10.1038/s43247-020-00078-3 ◽

2021 ◽

Vol 2 (1) ◽

Author(s):

Robert Constantinescu ◽

Aurelian Hopulele-Gligor ◽

Charles B. Connor ◽

Costanza Bonadonna ◽

Laura J. Connor ◽

...

Keyword(s):

Satellite Images ◽

Volcanic Hazard ◽

Source Parameters ◽

Volcanic Eruptions ◽

Column Height ◽

Explosive Eruptions ◽

Plume Height ◽

Direct Observations ◽

Hazard Assessments ◽

Explosive Volcanic Eruptions

AbstractEruption source parameters (in particular erupted volume and column height) are used by volcanologists to inform volcanic hazard assessments and to classify explosive volcanic eruptions. Estimations of source parameters are associated with large uncertainties due to various factors, including complex tephra sedimentation patterns from gravitationally spreading umbrella clouds. We modify an advection-diffusion model to investigate this effect. Using this model, source parameters for the climactic phase of the 2450 BP eruption of Pululagua, Ecuador, are different with respect to previous estimates (erupted mass: 1.5–5 × 1011 kg, umbrella cloud radius: 10–14 km, plume height: 20–30 km). We suggest large explosive eruptions are better classified by volume and umbrella cloud radius instead of volume or column height alone. Volume and umbrella cloud radius can be successfully estimated from deposit data using one numerical model when direct observations (e.g., satellite images) are not available.

Download Full-text

Reconstruction of Dynamically Evolving Volcanic Ash Clouds from Simulated Satellite Imagery

10.5194/egusphere-egu21-15527 ◽

2021 ◽

Author(s):

Tom Etchells ◽

Lucy Berthoud ◽

Kieran Wood ◽

Andrew Calway ◽

Matt Watson

Keyword(s):

Satellite Imagery ◽

Volcanic Ash ◽

Source Parameters ◽

Volcanic Eruptions ◽

Volcanic Plume ◽

Reconstruction Method ◽

Reconstruction Process ◽

Multiple User ◽

Reconstruction Performance ◽

Wide Range

Large volcanic eruptions can pose significant hazards over a range of domains. One such hazard is volcanic ash becoming suspended in the atmosphere. This can lead to significant risks to aviation, with the potential to cause severe or critical damage to jet engines. As such, the effective measurement and forecasting of ash contaminated airspace is of vital importance. Forecasts are generally produced using volcanic ash atmospheric transportation and dispersion models (ATDMs). Among the inputs to these models are eruption source parameters such as cloud-top height and cloud volume. One method of providing estimates of these source parameters, and to aid in characterising the size, shape, and distribution of a volcanic plume, is the reconstruction of the outer hull of the plume using multi-angle imagery.When considering platforms for generating this imagery, satellites provide a range of advantages. These include the potential for global coverage, the wide range of viewing angles during an orbital pass, and being safely removed from any potential volcanic hazards. This method of plume reconstruction has been previously demonstrated by the authors using simulated satellite imagery of a model volcanic plume. However, the simple model plume used during this previous work was static and did not evolve with time, an assumption that is not realistic.This presentation builds on the previous work and assess the efficacy of satellite imagery-based plume reconstruction under conditions closer to real-world, namely with a plume that is evolving with time. The time evolving plume model is produced via a Blender particle simulation. The images required for reconstruction are then generated at multiple user-determined time intervals and locations. A Space Carving reconstruction method is then applied to the imagery to generate the reconstructed plume. Performance and reconstruction accuracies are investigated by comparison of the reconstructed plume with the &#8216;ground-truth&#8217; simulation model. The impacts of a range of variables on the reconstruction performance are investigated, including plume size, imager properties, satellite orbit, and the use of additional satellites. The accuracy of the Blender plume simulation is compared with more mature plume simulations such as the University of Bristol PlumeRise model. These comparison models were not themselves used for the reconstruction process due to issues with the generation of accurate imagery.The improved simulation environment presented in this work further demonstrates the efficacy of a satellite-based reconstruction process for the measurement and forecasting of volcanic ash, potentially leading to improvements in hazard monitoring and aviation safety.

Download Full-text

Near-real-time volcanic cloud monitoring: insights into global explosive volcanic eruptive activity through analysis of Volcanic Ash Advisories

Bulletin of Volcanology ◽

10.1007/s00445-020-01419-y ◽

2021 ◽

Vol 83 (2) ◽

Author(s):

S. Engwell ◽

L. Mastin ◽

A. Tupper ◽

J. Kibler ◽

P. Acethorp ◽

...

Keyword(s):

Real Time ◽

Volcanic Activity ◽

Volcanic Ash ◽

Source Parameters ◽

Volcanic Eruptions ◽

Volcanic Hazards ◽

Process Data ◽

Cloud Monitoring ◽

Satellite Sensors ◽

Volcanic Cloud

AbstractUnderstanding the location, intensity, and likely duration of volcanic hazards is key to reducing risk from volcanic eruptions. Here, we use a novel near-real-time dataset comprising Volcanic Ash Advisories (VAAs) issued over 10 years to investigate global rates and durations of explosive volcanic activity. The VAAs were collected from the nine Volcanic Ash Advisory Centres (VAACs) worldwide. Information extracted allowed analysis of the frequency and type of explosive behaviour, including analysis of key eruption source parameters (ESPs) such as volcanic cloud height and duration. The results reflect changes in the VAA reporting process, data sources, and volcanic activity through time. The data show an increase in the number of VAAs issued since 2015 that cannot be directly correlated to an increase in volcanic activity. Instead, many represent increased observations, including improved capability to detect low- to mid-level volcanic clouds (FL101–FL200, 3–6 km asl), by higher temporal, spatial, and spectral resolution satellite sensors. Comparison of ESP data extracted from the VAAs with the Mastin et al. (J Volcanol Geotherm Res 186:10–21, 2009a) database shows that traditional assumptions used in the classification of volcanoes could be much simplified for operational use. The analysis highlights the VAA data as an exceptional resource documenting global volcanic activity on timescales that complement more widely used eruption datasets.

Download Full-text

The role of tropical volcanic eruptions in exacerbating Indian droughts

Scientific Reports ◽

10.1038/s41598-021-81566-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Suvarna Fadnavis ◽

Rolf Müller ◽

Tanusri Chakraborty ◽

T. P. Sabin ◽

Anton Laakso ◽

...

Keyword(s):

El Niño ◽

Climate Model ◽

El Nino ◽

Volcanic Eruptions ◽

Summer Monsoon Rainfall ◽

Indian Region ◽

Volcanic Plume ◽

Kelvin Wave ◽

Central Pacific ◽

Climate Model Simulations

AbstractThe Indian summer monsoon rainfall (ISMR) is vital for the livelihood of millions of people in the Indian region; droughts caused by monsoon failures often resulted in famines. Large volcanic eruptions have been linked with reductions in ISMR, but the responsible mechanisms remain unclear. Here, using 145-year (1871–2016) records of volcanic eruptions and ISMR, we show that ISMR deficits prevail for two years after moderate and large (VEI > 3) tropical volcanic eruptions; this is not the case for extra-tropical eruptions. Moreover, tropical volcanic eruptions strengthen El Niño and weaken La Niña conditions, further enhancing Indian droughts. Using climate-model simulations of the 2011 Nabro volcanic eruption, we show that eruption induced an El Niño like warming in the central Pacific for two consecutive years due to Kelvin wave dissipation triggered by the eruption. This El Niño like warming in the central Pacific led to a precipitation reduction in the Indian region. In addition, solar dimming caused by the volcanic plume in 2011 reduced Indian rainfall.

Download Full-text

Ensemble-based data assimilation of volcanic aerosols using FALL3D+PDAF

10.5194/egusphere-egu21-6774 ◽

2021 ◽

Author(s):

Leonardo Mingari ◽

Andrew Prata ◽

Federica Pardini

Keyword(s):

Data Assimilation ◽

Information Transfer ◽

High Performance ◽

Volcanic Ash ◽

Numerical Models ◽

Volcanic Eruptions ◽

Column Height ◽

Eruption Column ◽

Operational Environment ◽

Assimilation System

Modelling atmospheric dispersion and deposition of volcanic ash is becoming increasingly valuable for understanding the potential impacts of explosive volcanic eruptions on infrastructures, air quality and aviation. The generation of high-resolution forecasts depends on the accuracy and reliability of the input data for models. Uncertainties in key parameters such as eruption column height injection, physical properties of particles or meteorological fields, represent a major source of error in forecasting airborne volcanic ash. The availability of nearly real time geostationary satellite observations with high spatial and temporal resolutions provides the opportunity to improve forecasts in an operational context. Data assimilation (DA) is one of the most effective ways to reduce the error associated with the forecasts through the incorporation of available observations into numerical models. Here we present a new implementation of an ensemble-based data assimilation system based on the coupling between the FALL3D dispersal model and the Parallel Data Assimilation Framework (PDAF). The implementation is based on the last version release of FALL3D (versions 8.x) tailored to the extreme-scale computing requirements, which has been redesigned and rewritten from scratch in the framework of the EU Center of Excellence for Exascale in Solid Earth (ChEESE). The proposed methodology can be efficiently implemented in an operational environment by exploiting high-performance computing (HPC) resources. The FALL3D+PDAF system can be run in parallel and supports online-coupled DA, which allows an efficient information transfer through parallel communication. Satellite-retrieved data from recent volcanic eruptions were considered as input observations for the assimilation system.

Download Full-text

Revisiting the Krakatau 1883 Volcanic Aerosol Dispersal

10.5194/egusphere-egu21-10489 ◽

2021 ◽

Author(s):

Rafael Castro ◽

Tushar Mittal ◽

Stephen Self

Keyword(s):

Climate Model ◽

Global Climate ◽

Global Climate Model ◽

Volcanic Eruptions ◽

Climate Impact ◽

Volcanic Plume ◽

Quasi Biennial Oscillation ◽

Aerosol Cloud ◽

Pinatubo Eruption ◽

The Impact

The 1883 Krakatau eruption is one of the most well-known historical volcanic eruptions due to its significant global climate impact as well as first recorded observations of various aerosol associated optical and physical phenomena. Although much work has been done on the former by comparison of global climate model predictions/ simulations with instrumental and proxy climate records, the latter has surprisingly not been studied in similar detail. In particular, there is a wealth of observations of vivid red sunsets, blue suns, and other similar features, that can be used to analyze the spatio-temporal dispersal of volcanic aerosols in summer to winter 1883. Thus, aerosol cloud dispersal after the Krakatau eruption can be estimated, bolstered by aerosol cloud behavior as monitored by satellite-based instrument observations after the 1991 Pinatubo eruption. This is one of a handful of large historic eruptions where this analysis can be done (using non-climate proxy methods). In this study, we model particle trajectories of the Krakatau eruption cloud using the Hysplit trajectory model and compare our results with our compiled observational dataset (principally using Verbeek 1884, the Royal Society report, and Kiessling 1884).In particular, we explore the effect of different atmospheric states - the quasi-biennial oscillation (QBO) which impacts zonal movement of the stratospheric volcanic plume - to estimate the phase of the QBO in 1883 required for a fast-moving westward cloud. Since this alone is unable to match the observed latitudinal spread of the aerosols, we then explore the impact of an&#160; umbrella cloud (2000 km diameter) that almost certainly formed during such a large eruption. A large umbrella cloud, spreading over ~18 degrees within the duration of the climax of the eruption (6-8 hours), can lead to much quicker latitudinal spread than a point source (vent). We will discuss the results of the combined model (umbrella cloud and correct QBO phase) with historical accounts and observations, as well as previous work on the 1991 Pinatubo eruption. We also consider the likely impacts of water on aerosol concentrations and the relevance of this process for eruptions with possible significant seawater interactions, like Krakatau. We posit that the role of umbrella clouds is an under-appreciated, but significant, process for beginning to model the climatic impacts of large volcanic eruptions.

Download Full-text