scholarly journals Inclusion of Ash and SO<sub>2</sub> emissions from volcanic eruptions in WRF-CHEM: development and some applications

2012 ◽  
Vol 5 (3) ◽  
pp. 2571-2597 ◽  
Author(s):  
M. Stuefer ◽  
S. R. Freitas ◽  
G. Grell ◽  
P. Webley ◽  
S. Peckham ◽  
...  
Keyword(s):  
Explosive Eruption ◽  
Transport Model ◽  
Three Dimensional ◽  
Volcanic Eruptions ◽  
Weather Research And Forecasting ◽  
Tephra Fall ◽  
Additional Information ◽  
Volcanic Emission ◽  
Good Coincidence ◽  
Fall Deposits

Abstract. We describe a new functionality within the Weather Research and Forecasting model with coupled Chemistry (WRF-Chem) that allows simulating emission, transport, dispersion, transformation and sedimentation of pollutants released during volcanic activities. Emissions from both an explosive eruption case and relatively calm degassing situation are considered using the most recent volcanic emission databases. A preprocessor tool provides emission fields and additional information needed to establish the initial three-dimensional cloud umbrella/vertical distribution within the transport model grid, as well as the timing and duration of an eruption. From this source condition, the transport, dispersion and sedimentation of the ash-cloud can be realistically simulated by WRF-Chem using its own dynamics, physical parameterization as well as data assimilation. Examples of model validation include a comparison of tephra fall deposits from the 1989 eruption of Mount Redoubt (Alaska), and the dispersion of ash from the 2010 Eyjafjallajökull eruption in Iceland. Both model applications show good coincidence between WRF-Chem and observations.

scholarly journals Inclusion of ash and SO<sub>2</sub> emissions from volcanic eruptions in WRF-Chem: development and some applications

2013 ◽  
Vol 6 (2) ◽  
pp. 457-468 ◽  
Author(s):  
M. Stuefer ◽  
S. R. Freitas ◽  
G. Grell ◽  
P. Webley ◽  
S. Peckham ◽  
...  
Keyword(s):  
Transport Model ◽  
Three Dimensional ◽  
Wrf Model ◽  
Volcanic Eruptions ◽  
Weather Research And Forecasting ◽  
Tephra Fall ◽  
Additional Information ◽  
Volcanic Emission ◽  
Good Coincidence ◽  
Fall Deposits

Abstract. We describe a new functionality within the Weather Research and Forecasting (WRF) model with coupled Chemistry (WRF-Chem) that allows simulating emission, transport, dispersion, transformation and sedimentation of pollutants released during volcanic activities. Emissions from both an explosive eruption case and a relatively calm degassing situation are considered using the most recent volcanic emission databases. A preprocessor tool provides emission fields and additional information needed to establish the initial three-dimensional cloud umbrella/vertical distribution within the transport model grid, as well as the timing and duration of an eruption. From this source condition, the transport, dispersion and sedimentation of the ash cloud can be realistically simulated by WRF-Chem using its own dynamics and physical parameterization as well as data assimilation. Examples of model applications include a comparison of tephra fall deposits from the 1989 eruption of Mount Redoubt (Alaska) and the dispersion of ash from the 2010 Eyjafjallajökull eruption in Iceland. Both model applications show good coincidence between WRF-Chem and observations.

scholarly journals Extension of the WRF-Chem volcanic emission preprocessor to integrate complex source terms and evaluation for different emission scenarios of the Grimsvötn 2011 eruption

2020 ◽  
Vol 20 (11) ◽  
pp. 3099-3115
Author(s):  
Marcus Hirtl ◽  
Barbara Scherllin-Pirscher ◽  
Martin Stuefer ◽  
Delia Arnold ◽  
Rocio Baro ◽  
...  
Keyword(s):  
Transport Model ◽  
Vertical Wind Shear ◽  
Volcanic Eruptions ◽  
Complex Method ◽  
Emission Scenarios ◽  
Source Terms ◽  
Chemical Transport Model ◽  
Complex Source ◽  
Emission Fluxes ◽  
Volcanic Emission

Abstract. Volcanic eruptions may generate volcanic ash and sulfur dioxide (SO2) plumes with strong temporal and vertical variations. When simulating these changing volcanic plumes and the afar dispersion of emissions, it is important to provide the best available information on the temporal and vertical emission distribution during the eruption. The volcanic emission preprocessor of the chemical transport model WRF-Chem has been extended to allow the integration of detailed temporally and vertically resolved input data from volcanic eruptions. The new emission preprocessor is tested and evaluated for the eruption of the Grimsvötn volcano in Iceland 2011. The initial ash plumes of the Grimsvötn eruption differed significantly from the SO2 plumes, posing challenges to simulate plume dynamics within existing modelling environments: observations of the Grimsvötn plumes revealed strong vertical wind shear that led to different transport directions of the respective ash and SO2 clouds. Three source terms, each of them based on different assumptions and observational data, are applied in the model simulations. The emission scenarios range from (i) a simple approach, which assumes constant emission fluxes and a predefined vertical emission profile, to (ii) a more complex approach, which integrates temporarily varying observed plume-top heights and estimated emissions based on them, to (iii) the most complex method that calculates temporal and vertical variability of the emission fluxes based on satellite observations and inversion techniques. Comparisons between model results and independent observations from satellites, lidar, and surface air quality measurements reveal the best performance of the most complex source term.

Distribution and mass of tephra-fall deposits from volcanic eruptions of Sakurajima Volcano based on posteruption surveys

2018 ◽  
Vol 80 (4) ◽  
Author(s):  
Masayuki Oishi ◽  
Kuniaki Nishiki ◽  
Nobuo Geshi ◽  
Ryuta Furukawa ◽  
Yoshihiro Ishizuka ◽  
...  
Keyword(s):  
Volcanic Eruptions ◽  
Tephra Fall ◽  
Sakurajima Volcano ◽  
Fall Deposits

scholarly journals Extension of the WRF-Chem volcanic emission pre-processor to integrate complex source terms and evaluation for different emission scenarios of the Grimsvötn 2011 eruption

2020 ◽  
Author(s):  
Marcus Hirtl ◽  
Barbara Scherllin-Pirscher ◽  
Martin Stuefer ◽  
Delia Arnold ◽  
Rocio Baro ◽  
...  
Keyword(s):  
Transport Model ◽  
Vertical Wind Shear ◽  
Volcanic Eruptions ◽  
Complex Method ◽  
Emission Scenarios ◽  
Source Terms ◽  
Chemical Transport Model ◽  
Complex Source ◽  
Emission Fluxes ◽  
Volcanic Emission

Abstract. Volcanic eruptions may generate volcanic ash and sulfur dioxide (SO2) plumes with strong temporal and vertical variations. When simulating these changing volcanic plumes and the afar dispersion of emissions, it is important to provide the best available information on the temporal and vertical emission distribution during the eruption. The volcanic emission module of the chemical transport model WRF-Chem has been extended to allow integrating detailed temporally and vertically resolved input data from volcanic eruptions. The new emission pre-processor is tested and evaluated for the eruption of the Grimsvötn volcano in Iceland 2011. The initial ash plumes of the Grimsvötn eruption differed significantly from the SO2 plumes posing challenges to simulate plume dynamics within existing modelling environments: observations of the Grimsvötn plumes revealed strong vertical wind shear that led to different transport directions of the respective ash and SO2 clouds. Three source terms, each of them based on different assumptions and observational data are applied in the model simulations. The emission scenarios range from (i) a simple approach, which assumes constant emission fluxes and a pre-defined vertical emission profile, to (ii) a more complex approach, which integrates temporarily varying observed plume top heights and estimated emissions based on them, to (iii) the most complex method that calculates temporal and vertical variability of the emission fluxes based on satellite observations and inversion techniques. Comparisons between model results and independent observations from satellites, lidar and surface air quality measurements reveal best performance of the most complex source term.

scholarly journals Using WRF-Chem Volcano to model the in-plume halogen chemistry of Etna’s 2018 eruption

2020 ◽  
Author(s):  
Luke Surl ◽  
Simon Warnach ◽  
Thomas Wagner ◽  
Tjarda Roberts ◽  
Slimane Bekki
Keyword(s):  
Atmospheric Chemistry ◽  
Transport Model ◽  
Three Dimensional ◽  
Volcanic Eruptions ◽  
Satellite Observation ◽  
Mount Etna ◽  
Column Height ◽  
Stable Regime ◽  
Eruptive Event ◽  
Heterogenous Reaction

&lt;p&gt;Volcanic eruptions emit halogen-containing species in varying quantities, with their emission ratio to tracer species such SO&lt;sub&gt;2&lt;/sub&gt; varying between volcanoes, eruptions, and even phases of an eruptive event.&lt;/p&gt;&lt;p&gt;The bromine explosion is known to occur within volcanic plumes, converting bromine from HBr &amp;#8211; the primary form in which it is emitted &amp;#8211; to other forms, including the spectroscopically detectable BrO. Measurements of BrO have been made in the plumes of many volcanoes from both ground-based and satellite-based instruments. There also exist a small number of measurements of OClO.&lt;/p&gt;&lt;p&gt;We present results from WRF-Chem Volcano (WCV), a modified version of the three-dimensional regional atmospheric chemistry and transport model WRF-Chem and associated utilities. We have simulated the Christmas 2018 eruptive event of Mount Etna using a nested implementation the model at maximum lateral resolution of 1km, as well as a weaker emission plume representing Etna&amp;#8217;s more common quiescent degassing state. The plume of this 2018 eruption was observed remotely by the TROPOMI instrument.&lt;/p&gt;&lt;p&gt;WCV is able to model the transport and dispersion of the plume. We compare these model outputs to the satellite observations and use this to estimate the volcanic emission column height.&lt;/p&gt;&lt;p&gt;In terms of chemistry, WCV is able to reproduce the bromine explosion and the major features of the satellite observation &amp;#8211; including a cross-plume variation in the BrO/SO&lt;sub&gt;2&lt;/sub&gt; column ratio. We find that variations in the BrO/SO&lt;sub&gt;2&lt;/sub&gt; ratio are primarily caused by variations in the concentration of ozone. Ozone is consumed by bromine chemistry and is replenished by the mixing in of ozone-rich background air. This creates a zone of low ozone in the core of the plume which is consequently low in BrO and surrounded by a higher-ozone edge with a higher BrO/SO2 ratio.&lt;/p&gt;&lt;p&gt;For the temporal evolution of the plume, we find that the bromine-chemistry of a concentrated emission plume can be divided into four phases, also governed by ozone availability. In the last phase ozone limitation is minimal and the proportion of bromine in the form of BrO (and the BrO/SO2 ratio) is approximately stable. We find this stable regime also with a simulation of a weaker emission plume. These results could facilitate the use of remote-sensing BrO measurements as a means of quantifying total bromine emissions from volcanoes.&lt;/p&gt;&lt;p&gt;Oxidized forms of chlorine are modelled to be formed within the plume due to the heterogenous reaction of HOBr with HCl, forming BrCl that photolyzes and produces Cl radicals. We also investigate the extent to which mercury could be oxidized by halogens within the plume.&lt;/p&gt;

scholarly journals Tephra Deposit Inversion by Coupling TEPHRA2 With the Metropolis-Hastings Algorithm and Its Implications

2020 ◽  
Author(s):  
Qingyuan Yang ◽  
E Bruce Pitman ◽  
Marcus Bursik ◽  
Susanna F Jenkins
Keyword(s):  
Transport Model ◽  
Unit Area ◽  
Source Parameters ◽  
Volcanic Eruptions ◽  
Tephra Fall ◽  
Tephra Deposit ◽  
Synthetic Datasets ◽  
Performance Results ◽  
Thickness Measurements ◽  
Ash Transport

Abstract In this work we couple the Metropolis-Hastings algorithm with the volcanic ash transport model TEPHRA2, and present the coupled algorithm as a new method to estimate the Eruption Source Parameters of volcanic eruptions based on mass per unit area or thickness measurements of tephra fall deposits. Basic elements in the algorithm and how to implement it are introduced. Experiments are done with synthetic datasets. These experiments are designed to demonstrate that the algorithm works, and to show how inputs affect its performance. Results are presented as sample posterior distribution estimates for variables of interest. Advantages of the algorithm are that it has the ability to i) incorporate prior knowledge; ii) quantify the uncertainty; and iii) capture correlations between variables of interest in the estimated Eruption Source Parameters. A limitation is that some of the inputs need to be specifed subjectively. How and why such inputs affect the performance of the algorithm and how to specify them properly are explained and listed. Correlation between variables of interest are well-explained by the physics of tephra transport. We point out that in tephra deposit inversion, caution is needed in attempting to estimate Eruption Source Parameters, and wind direction and speed at each elevation level, as this increases the number of variables to be estimated. The algorithm is applied to a mass per unit area dataset of the tephra deposit from the 2011 Kirishima-Shinmoedake eruption. Simulation results from TEPHRA2 using posterior means from the algorithm are consistent with field observations, suggesting that this approach reliably reconstructs Eruption Source Parameters and wind conditions from the deposit.

scholarly journals A Computational Methodology for the Calibration of Tephra Transport Nowcasting at Sakurajima Volcano, Japan

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 104
Author(s):  
Alexandros P. Poulidis ◽  
Atsushi Shimizu ◽  
Haruhisa Nakamichi ◽  
Masato Iguchi
Keyword(s):  
Remote Sensing ◽  
High Resolution ◽  
Remote Sensing Data ◽  
Volcanic Eruptions ◽  
Weather Research And Forecasting ◽  
Sakurajima Volcano ◽  
Observation Network ◽  
Complementary Strategy ◽  
Physical Quantities ◽  
Do So

Ground-based remote sensing equipment have the potential to be used for the nowcasting of the tephra hazard from volcanic eruptions. To do so raw data from the equipment first need to be accurately transformed to tephra-related physical quantities. In order to establish these relations for Sakurajima volcano, Japan, we propose a methodology based on high-resolution simulations. An eruption that occurred at Sakurajima on 16 July 2018 is used as the basis of a pilot study. The westwards dispersal of the tephra cloud was ideal for the observation network that has been installed near the volcano. In total, the plume and subsequent tephra cloud were recorded by 2 XMP radars, 1 lidar and 3 optical disdrometers, providing insight on all phases of the eruption, from plume generation to tephra transport away from the volcano. The Weather Research and Forecasting (WRF) and FALL3D models were used to reconstruct the transport and deposition patterns. Simulated airborne tephra concentration and accumulated load were linked, respectively, to lidar backscatter intensity and radar reflectivity. Overall, results highlight the possibility of using such a high-resolution modelling-based methodology as a reliable complementary strategy to common approaches for retrieving tephra-related quantities from remote sensing data.

scholarly journals The vertical distribution of volcanic SO<sub>2</sub> plumes measured by IASI

2016 ◽  
Vol 16 (7) ◽  
pp. 4343-4367 ◽  
Author(s):  
Elisa Carboni ◽  
Roy G. Grainger ◽  
Tamsin A. Mather ◽  
David M. Pyle ◽  
Gareth E. Thomas ◽  
...  
Keyword(s):  
Volcanic Eruptions ◽  
Maximum Amount ◽  
The Other ◽  
High Spectral Resolution ◽  
Explosive Eruptions ◽  
Atmospheric Processes ◽  
Atmospheric Sounding ◽  
Volcanic Emission ◽  
The Vertical Distribution ◽  
Atmospheric Constituent

Abstract. Sulfur dioxide (SO2) is an important atmospheric constituent that plays a crucial role in many atmospheric processes. Volcanic eruptions are a significant source of atmospheric SO2 and its effects and lifetime depend on the SO2 injection altitude. The Infrared Atmospheric Sounding Interferometer (IASI) on the METOP satellite can be used to study volcanic emission of SO2 using high-spectral resolution measurements from 1000 to 1200 and from 1300 to 1410 cm−1 (the 7.3 and 8.7 µm SO2 bands) returning both SO2 amount and altitude data. The scheme described in Carboni et al. (2012) has been applied to measure volcanic SO2 amount and altitude for 14 explosive eruptions from 2008 to 2012. The work includes a comparison with the following independent measurements: (i) the SO2 column amounts from the 2010 Eyjafjallajökull plumes have been compared with Brewer ground measurements over Europe; (ii) the SO2 plumes heights, for the 2010 Eyjafjallajökull and 2011 Grimsvötn eruptions, have been compared with CALIPSO backscatter profiles. The results of the comparisons show that IASI SO2 measurements are not affected by underlying cloud and are consistent (within the retrieved errors) with the other measurements. The series of analysed eruptions (2008 to 2012) show that the biggest emitter of volcanic SO2 was Nabro, followed by Kasatochi and Grímsvötn. Our observations also show a tendency for volcanic SO2 to reach the level of the tropopause during many of the moderately explosive eruptions observed. For the eruptions observed, this tendency was independent of the maximum amount of SO2 (e.g. 0.2 Tg for Dalafilla compared with 1.6 Tg for Nabro) and of the volcanic explosive index (between 3 and 5).

scholarly journals Estimation of Volcanic Ash Emissions Using Trajectory-Based 4D-Var Data Assimilation

2016 ◽  
Vol 144 (2) ◽  
pp. 575-589 ◽  
Author(s):  
S. Lu ◽  
H. X. Lin ◽  
A. W. Heemink ◽  
G. Fu ◽  
A. J. Segers
Keyword(s):  
Data Assimilation ◽  
Vertical Distribution ◽  
Volcanic Ash ◽  
Transport Model ◽  
Volcanic Eruptions ◽  
Emission Rates ◽  
Plume Height ◽  
Ill Posed ◽  
Total Difference ◽  
The Vertical Distribution

Abstract Volcanic ash forecasting is a crucial tool in hazard assessment and operational volcano monitoring. Emission parameters such as plume height, total emission mass, and vertical distribution of the emission plume rate are essential and important in the implementation of volcanic ash models. Therefore, estimation of emission parameters using available observations through data assimilation could help to increase the accuracy of forecasts and provide reliable advisory information. This paper focuses on the use of satellite total-ash-column data in 4D-Var based assimilations. Experiments show that it is very difficult to estimate the vertical distribution of effective volcanic ash injection rates from satellite-observed ash columns using a standard 4D-Var assimilation approach. This paper addresses the ill-posed nature of the assimilation problem from the perspective of a spurious relationship. To reduce the influence of a spurious relationship created by a radiate observation operator, an adjoint-free trajectory-based 4D-Var assimilation method is proposed, which is more accurate to estimate the vertical profile of volcanic ash from volcanic eruptions. The method seeks the optimal vertical distribution of emission rates of a reformulated cost function that computes the total difference between simulated and observed ash columns. A 3D simplified aerosol transport model and synthetic satellite observations are used to compare the results of both the standard method and the new method.

scholarly journals Energetic particle induced intra-seasonal variability of ozone inside the Antarctic polar vortex observed in satellite data

2015 ◽  
Vol 15 (6) ◽  
pp. 3327-3338 ◽  
Author(s):  
T. Fytterer ◽  
M. G. Mlynczak ◽  
H. Nieder ◽  
K. Pérot ◽  
M. Sinnhuber ◽  
...  
Keyword(s):  
Geomagnetic Activity ◽  
Seasonal Variability ◽  
Transport Model ◽  
Three Dimensional ◽  
Polar Vortex ◽  
Quiet Time ◽  
Significance Level ◽  
Antarctic Polar Vortex ◽  
Ap Index ◽  
The Antarctic

Abstract. Measurements from 2002 to 2011 by three independent satellite instruments, namely MIPAS, SABER, and SMR on board the ENVISAT, TIMED, and Odin satellites are used to investigate the intra-seasonal variability of stratospheric and mesospheric O3 volume mixing ratio (vmr) inside the Antarctic polar vortex due to solar and geomagnetic activity. In this study, we individually analysed the relative O3 vmr variations between maximum and minimum conditions of a number of solar and geomagnetic indices (F10.7 cm solar radio flux, Ap index, ≥ 2 MeV electron flux). The indices are 26-day averages centred at 1 April, 1 May, and 1 June while O3 is based on 26-day running means from 1 April to 1 November at altitudes from 20 to 70 km. During solar quiet time from 2005 to 2010, the composite of all three instruments reveals an apparent negative O3 signal associated to the geomagnetic activity (Ap index) around 1 April, on average reaching amplitudes between −5 and −10% of the respective O3 background. The O3 response exceeds the significance level of 95% and propagates downwards throughout the polar winter from the stratopause down to ~ 25 km. These observed results are in good qualitative agreement with the O3 vmr pattern simulated with a three-dimensional chemistry-transport model, which includes particle impact ionisation.

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