scholarly journals Modelling SO<sub>2</sub> conversion into sulphates in the mid-troposphere with a 3D chemistry-transport model: the case of Mount Etna's eruption on April 12, 2012

2022 ◽  
Author(s):  
Mathieu Lachatre ◽  
Sylvain Mailler ◽  
Laurent Menut ◽  
Arineh Cholakian ◽  
Pasquale Sellitto ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Liquid Water ◽  
Transport Model ◽  
Mount Etna ◽  
Volcanic Plume ◽  
So2 Oxidation ◽  
Chemistry Transport Model ◽  
Radiative Balance ◽  
Sensitivity Tests ◽  
Short Time

Abstract. Volcanic activity is an important source of atmospheric sulphur dioxide (SO2), which, after conversion into sulphuric acid, induces impacts on, among others, rain acidity, human health, meteorology and the radiative balance of the atmosphere. This work focuses on the conversion of SO2 into sulphates (, S(+VI)) in the mid-tropospheric volcanic plume emitted by the explosive eruption of Mount Etna (Italy) on Apr. 12, 2012, using the CHIMERE chemistry-transport model. Since volcanic plume location and composition depend on several often poorly constrained parameters, using a chemistry-transport model allows us to study the sensitivity of SO2 oxidation to multiple aspects such as volcanic water emissions, transition metal emissions, plume diffusion and plume altitude. Our results show that in the mid-troposphere, two pathways contribute to sulphate production, the oxidation of SO2 by OH in the gaseous phase (70 %), and the aqueous oxidation by O2 catalyzed by Mn2+ and Fe3+ ions (25 %). The oxidation in aqueous phase is the faster process, but in the mid-troposphere, liquid water is scarce, therefore the relative share of gaseous oxidation can be important. After one day in the mid-troposphere, about 0.5 % of the volcanic SO2 was converted to sulphates through the gaseous process. Because of the nonlinear dependency of the kinetics in the aqueous phase to the amount of volcanic water emitted and on the availability of transition metals in the aqueous phase, several experiments have been designed to determine the prominence of different parameters. Our simulations show that during the short time that liquid water remains in the plume, around 0.4 % of sulphates manage to quickly enter the liquid phase. Sensitivity tests regarding the advection scheme have shown that this scheme must be chosen wisely, as dispersion will impact both oxidation pathways explained above.

The observation of different aerosols types in the Mount Etna environment and their relative and mutual impacts on local radiative balance

2021 ◽  
Author(s):  
Pasquale Sellitto ◽  
Giuseppe Salerno ◽  
Simona Scollo ◽  
Alcide Giorgio di Sarra ◽  
Antonella Boselli ◽  
...  
Keyword(s):  
Spatial Scales ◽  
Source Parameters ◽  
Mount Etna ◽  
Volcanic Plume ◽  
Dynamical Regime ◽  
Radiative Balance ◽  
Volcanic Aerosols ◽  
Aerosol Types ◽  
Lidar Observations

&lt;p&gt;The EPL-RADIO (Etna Plume Lab - Radioactive Aerosols and other source parameters for better atmospheric Dispersion and Impact estimatiOns) and EPL-REFLECT (near-source estimations of Radiative EFfects of voLcanic aErosols for Climate and air quality sTudies) projects, funded by the EC Horizon2020 ENVRIplus and EUROVOLC Transnational Access to European Observatories programmes, aim to advance the understanding of Mount Etna as a persistent source of atmospheric aerosols and its impact on the&amp;#160; radiative budget at proximal to regional spatial scales. Research was tackled by carrying out three campaigns in the summers of 2016, 2017 and 2019 to observe the volcanic plume produced by passive degassing, proximally and distally from the summit craters, using a wide array of remote sensing and in situ instruments. Diverse data are collected to explore the link of inner degassing mechanisms to the characterisation of near-source aerosol physicochemical properties and subsequent impacts on the atmosphere, environment and regional climate system.&lt;/p&gt;&lt;p&gt;The results of the three campaigns have shown that the volcanic plume emitted by Mount Etna often mixes with aerosols of different origins generating a complex layered pattern. Frequent mineral dust transport events were observed by both LiDAR observations located at Serra La Nave (~7 km south-west from summit craters) and at a medium-term radiometric station, equipped with a Multi-Filter Rotating Shadowband Radiometer (MFRSR), and other instruments located at Milo (~10 km eastwards from the craters). LiDAR observations also allowed to study the coexistence of volcanic aerosols and biomass burning particles from local to more distal smoke plumes transports (like for the well-documented large fires from continental southern Italy in July 2017). In situ filter and optical particles counter measurements confirmed the presence of dust at Milo. The interaction/mixing among volcanic, wildfire, and dust aerosols occurs in an overall dynamical regime which appears to be dominated by sea breeze, which is strengthened by the presence of the dark volcanic lava flanks. Photolysis process also possibly play a role in determining the daily evolution of the aerosol plume.&lt;/p&gt;&lt;p&gt;The sources of these different aerosol types are studied in detail using Lagrangian trajectories and meteorological data. Off-line radiative transfer calculations, using EPL-RADIO/REFLECT observations as input data, are used to estimate the relative radiative impact of the different aerosol types with respect to the background passive-degassing aerosols coming from Mount Etna.&lt;/p&gt;

scholarly journals Towards a representation of halogen chemistry within volcanic plumes in a chemistry transport model

2014 ◽  
Vol 7 (2) ◽  
pp. 2581-2650 ◽  
Author(s):  
L. Grellier ◽  
V. Marécal ◽  
B. Josse ◽  
P. D. Hamer ◽  
T. J. Roberts ◽  
...  
Keyword(s):  
Transport Model ◽  
Computational Cost ◽  
Ambient Air ◽  
Heterogeneous Reactions ◽  
Tropospheric Chemistry ◽  
Volcanic Plume ◽  
Large Set ◽  
Chemistry Transport Model ◽  
Volcanic Plumes ◽  
The Impact

Abstract. Volcanoes are a known source of halogens to the atmosphere. HBr volcanic emissions lead rapidly to the formation of BrO within volcanic plumes as shown by recent work based on observations and models. BrO, having a longer residence time in the atmosphere than HBr, is expected to have a significant impact on tropospheric chemistry, at least at the local and regional scales. The objective of this paper is to prepare a framework that will allow 3-D modelling of volcanic halogen emissions in order to determine their fate within the volcanic plume and then in the atmosphere at the regional and global scales. This work is based on a 1-D configuration of the chemistry transport model MOCAGE whose low computational cost allows us to perform a large set of sensitivity studies. This paper studies the Etna eruption on the 10 May 2008 that took place just before night time. Adaptations are made to MOCAGE to be able to produce the chemistry occurring within the volcanic plume. A simple sub-grid scale parameterization of the volcanic plume is implemented and tested. The use of this parameterization in a 0.5° × 0.5° configuration (typical regional resolution) has an influence on the partitioning between the various bromine compounds both during the eruption period and also during the night period immediately afterwards. During the day after the eruption, simulations both with and without parameterizations give very similar results that are consistent with the tropospheric column of BrO and SO2 in the volcanic plume derived from GOME-2 observations. Tests have been performed to evaluate the sensitivity of the results to the mixing between ambient air and the magmatic air at very high temperature at the crater vent that modifies the composition of the emission, and in particular the sulphate aerosol content that is key compound in the BrO production. Simulations show that the plume chemistry is not very sensitive to the assumptions used for the mixing parameter (relative quantity of ambient air mixed with magmatic air in the mixture) that is not well known. This is because there is no large change in the compounds limiting/favouring the BrO production in the plume. The impact of the model grid resolution is also tested in view of future 3-D-simulations at the global scale. A dilution of the emitted gases and aerosols is observed when using the typical global resolution (2°) as compared to a typical regional resolution (0.5°), as expected. Taking this into account, the results of the 2° resolution simulations are consistent with the GOME-2 observations. In general the simulations at 2° resolution are less efficient at producing BrO after the emission both with and without the subgrid-scale parameterization. The differences are mainly due to an interaction between concentration effects than stem from using a reduced volume in the 0.5° resolution combined with second order rate kinetics. The last series of tests were on the mean radius assumed for the sulphate aerosols that indirectly impacts the production of BrO by heterogeneous reactions. The simulations show that the BrO production is sensitive to this parameter with a stronger production when smaller aerosols are assumed. These results will be used to guide the implementation of volcanic halogen emissions in the 3-D configuration of MOCAGE.

scholarly journals Using the 3D MOCAGE CTM to simulate the chemistry of halogens in the volcanic plume of Etna's eruption in December 2018 at the regional scale

2021 ◽  
Author(s):  
Herizo Narivelo ◽  
Virginie Marécal ◽  
Paul David Hamer ◽  
Luke Surl ◽  
Tjarda Roberts ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Transport Model ◽  
Regional Scale ◽  
Mount Etna ◽  
Volcanic Plume ◽  
Gaseous Species ◽  
Modelling Studies ◽  
Order Of Magnitude ◽  
The Impact ◽  
Halogen Species

&lt;p&gt;&lt;span&gt;Volcanoes emit different gaseous species, SO&amp;#8322; and in particular halogen species especially bromine and chlorine compounds. In general, halogens play an important role in the atmosphere by contributing to ozone depletion in the stratosphere (WMO Ozone assessment, 2018) and by modifying air composition and oxidizing capacity in the troposphere (Von Glasow et al. 2004). The halogen species emitted by volcanoes are halides. The chemical processing occurring within the plume leads to the formation of BrO from HBr following the &amp;#8216;bromine explosion&amp;#8217; mechanism as evidenced from both observations and modelling (e.g., Bobrowski et al. Nature, 2003; Roberts et al., Chem. Geol. 2009). Oxidized forms of chlorine and bromine are modelled to be formed within the plume due to the heterogenous reaction of HOBr with HCl and HBr, forming BrCl and Br&amp;#8322; that photolyses and produces Br and Cl radicals. So far, modelling studies were mainly focused on the very local scale and processes occurring within a few hours after eruption.&lt;/span&gt;&lt;/p&gt;&lt;p&gt;&lt;span&gt;In this study, the objective is to go a step further by analyzing the impact at the regional scale over the Mediterranean basin of a Mt Etna eruption event. For this, we use the MOCAGE model (Guth et al., GMD, 2016), a chemistry transport model run with a resolution of 0.2&amp;#176;x 0.2&amp;#176;, to quantify the impacts of the halogens species emitted by the volcano on the tropospheric composition. We have selected here the case of the eruption of Mount Etna around Christmas 2018 characterised by large amounts of emissions over several days (Calvari et al., remote sensing 2020; Corrdadini et al., remote sensing 2020). The results show that MOCAGE represents rather well the chemistry of the halogens in the volcanic plume because it established theory of plume chemistry. The bromine explosion process takes place on the first day of the eruption and even more strongly the day after, with a rapid increase of the in-plume BrO concentrations and a corresponding strong&amp;#160;reduction of ozone and NO2&amp;#160;concentrations.&lt;/span&gt;&lt;/p&gt;&lt;p&gt;&lt;span&gt;We also compared MOCAGE results with the WRF-CHEM model simulations for the same case study. We note that the tropospheric column of BrO and SO&amp;#8322; in the two models have the same order of magnitude with more rapid bromine explosion occurring in WRF-CHEM simulations. Finally, we compared the MOCAGE results to tropospheric columns of BrO and SO&lt;/span&gt;&lt;sub&gt;&lt;span&gt;2&lt;/span&gt;&lt;/sub&gt;&lt;span&gt; retrieved from TROPOMI spaceborne instrument.&lt;/span&gt;&lt;/p&gt;

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

2021 ◽  
Vol 13 (20) ◽  
pp. 4037
Author(s):  
Umberto Rizza ◽  
Franck Donnadieu ◽  
Salvatore Magazu ◽  
Giorgio Passerini ◽  
Giuseppe Castorina ◽  
...  
Keyword(s):  
Doppler Radar ◽  
Transport Model ◽  
Source Parameters ◽  
Radar System ◽  
Mount Etna ◽  
Volcanic Plume ◽  
Time Varying ◽  
North East ◽  
Joint Approach ◽  
Plume Transport

The purpose of the present paper is to investigate the effects of variable eruption source parameters on volcanic plume transport in the Mediterranean basin after the paroxysm of Mount Etna on 23 November 2013. This paroxysm was characterized by a north-east transport of ash and gas, caused by a low-pressure system in northern Italy. It is evaluated here in a joint approach considering the WRF-Chem model configured with eruption source parameters (ESPs) obtained elaborating the raw data from the VOLDORAD-2B (V2B) Doppler radar system. This allows the inclusion of the transient and fluctuating nature of the volcanic emissions to accurately model the atmospheric dispersion of ash and gas. Two model configurations were considered: the first with the climax values for the ESP and the second with the time-varying ESP according to the time profiles of the mass eruption rate recorded by the V2B radar. It is demonstrated that the second configuration produces a considerably better comparison with satellite retrievals from different sensors platforms (Ozone Mapping and Profiler Suite, Meteosat Second-Generation Spinning Enhanced Visible and Infrared Imager, and Visible Infrared Imaging Radiometer Suite). In the context of volcanic ash transport dispersion modeling, our results indicate the need for (i) the use of time-varying ESP, and (ii) a joint approach between an online coupled chemical transport model like WRF-Chem and direct near-source measurements, such as those carried out by the V2B Doppler radar system.

scholarly journals Evaluating BC and NO<sub>x</sub> emission inventories for the Paris region from MEGAPOLI aircraft measurements

2014 ◽  
Vol 14 (21) ◽  
pp. 29237-29304 ◽  
Author(s):  
H. Petetin ◽  
M. Beekmann ◽  
A. Colomb ◽  
H. A. C. Denier van der Gon ◽  
J.-C. Dupont ◽  
...  
Keyword(s):  
Transport Model ◽  
Vertical Mixing ◽  
Nox Emissions ◽  
Error Sources ◽  
Chemistry Transport Model ◽  
Airborne Measurements ◽  
Boundary Layer Height ◽  
Uncertainty Sources ◽  
Novel Approach ◽  
Sensitivity Tests

Abstract. High uncertainties affect black carbon (BC) emissions and, despite its important impact on air pollution and climate, very few BC emissions evaluations are found in the literature. This paper presents a novel approach, based on airborne measurements across the Paris plume, developed in order to evaluate BC and NOx emissions at the scale of a whole agglomeration. The methodology consists in integrating, for each transect, across the plume observed and simulated concentrations above background. This allows minimizing several error sources in the model (e.g. representativeness, chemistry, plume lateral dispersion). The procedure is applied with the CHIMERE chemistry-transport model to three inventories – the EMEP inventory, and the so-called TNO and TNO-MP inventories – over the month of July 2009. Various systematic uncertainty sources both in the model (e.g. boundary layer height, vertical mixing, deposition) and in observations (e.g. BC nature) are discussed and quantified, notably though sensitivity tests. A statistically significant (but moderate) overestimation is obtained on the TNO BC emissions and on EMEP and TNO-MP NOx emissions, as well as on the BC/NOx emission ratio in TNO-MP. The benefit of the airborne approach is discussed through a comparison with the BC/NOx ratio at a ground site in Paris, which additionally suggests potential error compensations in the BC emissions spatial distribution over the agglomeration.

scholarly journals Variability of springtime transpacific pollution transport during 2000–2006: the INTEX-B mission in the context of previous years

2010 ◽  
Vol 10 (3) ◽  
pp. 1345-1359 ◽  
Author(s):  
G. G. Pfister ◽  
L. K. Emmons ◽  
D. P. Edwards ◽  
A. Arellano ◽  
T. Campos ◽  
...  
Keyword(s):  
Transport Model ◽  
Pollution Transport ◽  
Chemistry Transport Model ◽  
Pollution Levels ◽  
Annual Variability ◽  
Source Regions ◽  
Time Period ◽  
The Pacific ◽  
The Us ◽  
Transport Experiment

Abstract. We analyze the transport of pollution across the Pacific during the NASA INTEX-B (Intercontinental Chemical Transport Experiment Part B) campaign in spring 2006 and examine how this year compares to the time period for 2000 through 2006. In addition to aircraft measurements of carbon monoxide (CO) collected during INTEX-B, we include in this study multi-year satellite retrievals of CO from the Measurements of Pollution in the Troposphere (MOPITT) instrument and simulations from the chemistry transport model MOZART-4. Model tracers are used to examine the contributions of different source regions and source types to pollution levels over the Pacific. Additional modeling studies are performed to separate the impacts of inter-annual variability in meteorology and dynamics from changes in source strength. Interannual variability in the tropospheric CO burden over the Pacific and the US as estimated from the MOPITT data range up to 7% and a somewhat smaller estimate (5%) is derived from the model. When keeping the emissions in the model constant between years, the year-to-year changes are reduced (2%), but show that in addition to changes in emissions, variable meteorological conditions also impact transpacific pollution transport. We estimate that about 1/3 of the variability in the tropospheric CO loading over the contiguous US is explained by changes in emissions and about 2/3 by changes in meteorology and transport. Biomass burning sources are found to be a larger driver for inter-annual variability in the CO loading compared to fossil and biofuel sources or photochemical CO production even though their absolute contributions are smaller. Source contribution analysis shows that the aircraft sampling during INTEX-B was fairly representative of the larger scale region, but with a slight bias towards higher influence from Asian contributions.

scholarly journals The On-Line Integrated Mesoscale Chemistry Model BOLCHEM

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 192
Author(s):  
Rita Cesari ◽  
Tony Christian Landi ◽  
Massimo D’Isidoro ◽  
Mihaela Mircea ◽  
Felicita Russo ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Transport Model ◽  
Horizontal Resolution ◽  
Integration Step ◽  
Chemistry Transport Model ◽  
European Environmental Agency ◽  
On Line ◽  
One Year ◽  
Pm2.5 And Pm10 ◽  
Monitoring Service

This work presents the on-line coupled meteorology–chemistry transport model BOLCHEM, based on the hydrostatic meteorological BOLAM model, the gas chemistry module SAPRC90, and the aerosol dynamic module AERO3. It includes parameterizations to describe natural source emissions, dry and wet removal processes, as well as the transport and dispersion of air pollutants. The equations for different processes are solved on the same grid during the same integration step, by means of a time-split scheme. This paper describes the model and its performance at horizontal resolution of 0.2∘× 0.2∘ over Europe and 0.1∘× 0.1∘ in a nested configuration over Italy, for one year run (December 2009–November 2010). The model has been evaluated against the AIRBASE data of the European Environmental Agency. The basic statistics for higher resolution simulations of O3, NO2 and particulate matter concentrations (PM2.5 and PM10) have been compared with those from Copernicus Atmosphere Monitoring Service (CAMS) ensemble median. In summer, for O3 we found a correlation coefficient R of 0.72 and mean bias of 2.15 over European domain and a correlation coefficient R of 0.67 and mean bias of 2.36 over Italian domain. PM10 and PM2.5 are better reproduced in the winter, the latter with a correlation coefficient R of 0.66 and the mean bias MB of 0.35 over Italian domain.

Aerosol Dynamics Modelling in the Regional Chemistry Transport Model System Eurad

1998 ◽  
pp. 721-722
Author(s):  
Ingmar J. Ackermann ◽  
Heinz Hass ◽  
A. Ebel ◽  
M. Memmesheimer ◽  
H. J. Jakobs
Keyword(s):  
Transport Model ◽  
Model System ◽  
Chemistry Transport Model ◽  
Aerosol Dynamics ◽  
Dynamics Modelling

scholarly journals An advanced scheme for wet scavenging and liquid-phase chemistry in a regional online-coupled chemistry transport model

2013 ◽  
Vol 13 (3) ◽  
pp. 1177-1192 ◽  
Author(s):  
C. Knote ◽  
D. Brunner
Keyword(s):  
Aqueous Phase ◽  
Climate Model ◽  
Transport Model ◽  
Measurement Data ◽  
Coupled System ◽  
Cloud Microphysics ◽  
Microphysics Scheme ◽  
Meteorological Model ◽  
Wet Scavenging ◽  
Phase Chemistry

Abstract. Clouds are reaction chambers for atmospheric trace gases and aerosols, and the associated precipitation is a major sink for atmospheric constituents. The regional chemistry-climate model COSMO-ART has been lacking a description of wet scavenging of gases and aqueous-phase chemistry. In this work we present a coupling of COSMO-ART with a wet scavenging and aqueous-phase chemistry scheme. The coupling is made consistent with the cloud microphysics scheme of the underlying meteorological model COSMO. While the choice of the aqueous-chemistry mechanism is flexible, the effects of a simple sulfur oxidation scheme are shown in the application of the coupled system in this work. We give details explaining the coupling and extensions made, then present results from idealized flow-over-hill experiments in a 2-D model setup and finally results from a full 3-D simulation. Comparison against measurement data shows that the scheme efficiently reduces SO2 trace gas concentrations by 0.3 ppbv (−30%) on average, while leaving O3 and NOx unchanged. PM10 aerosol mass was increased by 10% on average. While total PM2.5 changes only little, chemical composition is improved notably. Overestimations of nitrate aerosols are reduced by typically 0.5–1 μg m−3 (up to −2 μg m−3 in the Po Valley) while sulfate mass is increased by 1–1.5 μg m−3 on average (up to 2.5 μg m−3 in Eastern Europe). The effect of cloud processing of aerosols on its size distribution, i.e. a shift towards larger diameters, is observed. Compared against wet deposition measurements the system tends to underestimate the total wet deposited mass for the simulated case study.

scholarly journals Top-Down NOX Emissions of European Cities Based on the Downwind Plume of Modelled and Space-Borne Tropospheric NO2 Columns

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2893 ◽  
Author(s):  
Willem W. Verstraeten ◽  
Klaas Folkert Boersma ◽  
John Douros ◽  
Jason E. Williams ◽  
Henk Eskes ◽  
...  
Keyword(s):  
Urban Areas ◽  
Transport Model ◽  
Nox Emissions ◽  
Inventory Data ◽  
Ozone Monitoring Instrument ◽  
Top Down ◽  
Chemistry Transport Model ◽  
European Cities ◽  
Tropospheric No2

Top-down estimates of surface NOX emissions were derived for 23 European cities based on the downwind plume decay of tropospheric nitrogen dioxide (NO2) columns from the LOTOS-EUROS (Long Term Ozone Simulation-European Ozone Simulation) chemistry transport model (CTM) and from Ozone Monitoring Instrument (OMI) satellite retrievals, averaged for the summertime period (April–September) during 2013. Here we show that the top-down NOX emissions derived from LOTOS-EUROS for European urban areas agree well with the bottom-up NOX emissions from the MACC-III inventory data (R2 = 0.88) driving the CTM demonstrating the potential of this method. OMI top-down NOX emissions over the 23 European cities are generally lower compared with the MACC-III emissions and their correlation is slightly lower (R2 = 0.79). The uncertainty on the derived NO2 lifetimes and NOX emissions are on average ~55% for OMI and ~63% for LOTOS-EUROS data. The downwind NO2 plume method applied on both LOTOS-EUROS and OMI tropospheric NO2 columns allows to estimate NOX emissions from urban areas, demonstrating that this is a useful method for real-time updates of urban NOX emissions with reasonable accuracy.

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