Toward quantitative forecasts of volcanic ash dispersal: Using satellite retrievals for optimal estimation of source terms

2017 ◽  
Vol 122 (15) ◽  
pp. 8187-8206 ◽  
Author(s):  
Meelis J. Zidikheri ◽  
Christopher Lucas ◽  
Rodney J. Potts
Keyword(s):  
Volcanic Ash ◽  
Optimal Estimation ◽  
Source Terms ◽  
Satellite Retrievals ◽  
Ash Dispersal

scholarly journals The fate of volcanic ash: premature or delayed sedimentation?

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Eduardo Rossi ◽  
Gholamhossein Bagheri ◽  
Frances Beckett ◽  
Costanza Bonadonna
Keyword(s):  
Residence Time ◽  
Volcanic Ash ◽  
Volcanic Eruptions ◽  
Theoretical Description ◽  
Particle Sedimentation ◽  
Weather Modeling ◽  
Explosive Volcanic Eruptions ◽  
Travel Distances ◽  
Ash Dispersal

AbstractA large amount of volcanic ash produced during explosive volcanic eruptions has been found to sediment as aggregates of various types that typically reduce the associated residence time in the atmosphere (i.e., premature sedimentation). Nonetheless, speculations exist in the literature that aggregation has the potential to also delay particle sedimentation (rafting effect) even though it has been considered unlikely so far. Here, we present the first theoretical description of rafting that demonstrates how delayed sedimentation may not only occur but is probably more common than previously thought. The fate of volcanic ash is here quantified for all kind of observed aggregates. As an application to the case study of the 2010 eruption of Eyjafjallajökull volcano (Iceland), we also show how rafting can theoretically increase the travel distances of particles between 138–710 μm. These findings have fundamental implications for hazard assessment of volcanic ash dispersal as well as for weather modeling.

scholarly journals The Campanian Ignimbrite Eruption: New Data on Volcanic Ash Dispersal and Its Potential Impact on Human Evolution

PLoS ONE ◽  
2013 ◽  
Vol 8 (6) ◽  
pp. e65839 ◽  
Author(s):  
Kathryn E. Fitzsimmons ◽  
Ulrich Hambach ◽  
Daniel Veres ◽  
Radu Iovita
Keyword(s):  
Human Evolution ◽  
Volcanic Ash ◽  
Campanian Ignimbrite ◽  
Potential Impact ◽  
Ash Dispersal

scholarly journals Forecasting volcanic ash dispersal and coeval resuspension during the April–May 2015 Calbuco eruption

2016 ◽  
Vol 321 ◽  
pp. 44-57 ◽  
Author(s):  
F. Reckziegel ◽  
E. Bustos ◽  
L. Mingari ◽  
W. Báez ◽  
G. Villarosa ◽  
...  
Keyword(s):  
Volcanic Ash ◽  
Ash Dispersal

scholarly journals Volcanic ash forecast using ensemble-based data assimilation: the Ensemble Transform Kalman Filter coupled with FALL3D-7.2 model (ETKF-FALL3D, version 1.0)

2019 ◽  
Author(s):  
Soledad Osores ◽  
Juan Ruiz ◽  
Arnau Folch ◽  
Estela Collini
Keyword(s):  
Kalman Filter ◽  
Data Assimilation ◽  
Volcanic Ash ◽  
Source Parameters ◽  
Joint Estimation ◽  
Volcanic Ash Cloud ◽  
Ensemble Transform Kalman Filter ◽  
Ensemble Transform ◽  
Ash Cloud ◽  
Ash Dispersal

Abstract. Quantitative volcanic ash cloud forecasts are prone to uncertainties coming from the source term quantification (e.g. eruption strength or vertical distribution of the emitted particles), with consequent implications on operational ash impact assessment. We present an ensemble-based data assimilation and forecast system for volcanic ash dispersal and deposition aimed at reducing uncertainties related to eruption source parameters. The FALL3D atmospheric dispersal model is coupled with the Ensemble Transform Kalman Filter (ETKF) data assimilation technique by combining ash mass loading observations with ash dispersal simulations in order to obtain a better joint estimation of 3D ash concentration and source parameters. The ETKF-FALL3D data assimilation system is evaluated performing Observation System Simulation Experiments (OSSE) in which synthetic observations of fine ash mass loadings are assimilated. The evaluation of the ETKF-FALL3D system considering reference states of steady and time-varying eruption source parameters shows that the assimilation process gives both better estimations of ash concentration and time-dependent optimized values of eruption source parameters. The joint estimation of concentrations and source parameters leads to a better analysis and forecast of the 3D ash concentrations. Results show the potential of the methodology to improve volcanic ash cloud forecasts in operational contexts.

scholarly journals Using Satellite Data to Determine Empirical Relationships between Volcanic Ash Source Parameters

Atmosphere ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 342 ◽  
Author(s):  
Meelis J. Zidikheri ◽  
Chris Lucas
Keyword(s):  
Case Studies ◽  
Volcanic Ash ◽  
Dispersion Model ◽  
Source Parameters ◽  
Difficult Problem ◽  
Emission Rates ◽  
Empirical Relationships ◽  
Mass Load ◽  
Satellite Retrievals ◽  
Mass Loads

Poor knowledge of dispersion model source parameters related to quantities such as the total fine ash mass emission rate, its effective spatial distribution, and particle size distribution makes the provision of quantitative forecasts of volcanic ash a difficult problem. To ameliorate this problem, we make use of satellite-retrieved mass load data from 14 eruption case studies to estimate fine ash mass emission rates and other source parameters by an inverse modelling procedure, which requires multidimensional sampling of several thousand trial simulations with different values of source parameters. We then estimate the dependence of these optimal source parameters on eruption height. We show that using these empirical relationships in a data assimilation procedure leads to substantial improvements to the forecasts of ash mass loads, with the use of empirical relationships between parameters and eruption height having the added advantage of computational efficiency because of dimensional reduction. In addition, the use of empirical relationships, which encode information in satellite retrievals from past case studies, implies that quantitative forecasts can still be issued even when satellite retrievals of mass load are not available in real time due to cloud cover or other reasons, making it especially useful for operations in the tropics where ice and water clouds are ubiquitous.

scholarly journals Quantifying volcanic ash dispersal and impact of the Campanian Ignimbrite super-eruption

2012 ◽  
Vol 39 (10) ◽  
pp. n/a-n/a ◽  
Author(s):  
A. Costa ◽  
A. Folch ◽  
G. Macedonio ◽  
B. Giaccio ◽  
R. Isaia ◽  
...  
Keyword(s):  
Volcanic Ash ◽  
Campanian Ignimbrite ◽  
Ash Dispersal

scholarly journals FALL3D-8.0: a computational model for atmospheric transport and deposition of particles, aerosols and radionuclides – Part 2: Model validation

2021 ◽  
Vol 14 (1) ◽  
pp. 409-436
Author(s):  
Andrew T. Prata ◽  
Leonardo Mingari ◽  
Arnau Folch ◽  
Giovanni Macedonio ◽  
Antonio Costa
Keyword(s):  
Case Studies ◽  
Model Validation ◽  
Volcanic Ash ◽  
Atmospheric Transport ◽  
Test Suite ◽  
Structure Amplitude ◽  
Satellite Retrievals ◽  
Mt Etna ◽  
Ash Cloud ◽  
Tephra Fallout

Abstract. This paper presents model validation results for the latest version release of the FALL3D atmospheric transport model. The code has been redesigned from scratch to incorporate different categories of species and to overcome legacy issues that precluded its preparation towards extreme-scale computing. The model validation is based on the new FALL3D-8.0 test suite, which comprises a set of four real case studies that encapsulate the major features of the model; namely, the simulation of long-range fine volcanic ash dispersal, volcanic SO2 dispersal, tephra fallout deposits and the dispersal and deposition of radionuclides. The first two test suite cases (i.e. the June 2011 Puyehue-Cordón Caulle ash cloud and the June 2019 Raikoke SO2 cloud) are validated against geostationary satellite retrievals and demonstrate the new FALL3D data insertion scheme. The metrics used to validate the volcanic ash and SO2 simulations are the structure, amplitude and location (SAL) metric and the figure of merit in space (FMS). The other two test suite cases (i.e. the February 2013 Mt. Etna ash cloud and associated tephra fallout deposit, and the dispersal of radionuclides resulting from the 1986 Chernobyl nuclear accident) are validated with scattered ground-based observations of deposit load and local particle grain size distributions and with measurements from the Radioactivity Environmental Monitoring database. For validation of tephra deposit loads and radionuclides, we use two variants of the normalised root-mean-square error metric. We find that FALL3D-8.0 simulations initialised with data insertion consistently improve agreement with satellite retrievals at all lead times up to 48 h for both volcanic ash and SO2 simulations. In general, SAL scores lower than 1.5 and FMS scores greater than 0.40 indicate acceptable agreement with satellite retrievals of volcanic ash and SO2. In addition, we show very good agreement, across several orders of magnitude, between the model and observations for the 2013 Mt. Etna and 1986 Chernobyl case studies. Our results, along with the validation datasets provided in the publicly available test suite, form the basis for future improvements to FALL3D (version 8 or later) and also allow for model intercomparison studies.

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