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Igor Konovalov   Dr.  Senior Scientist or Principal Investigator 
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Igor Konovalov published an article in April 2017.
Top co-authors See all
C. George

334 shared publications

Institut de Recherches Sur la Catalyse et l'Environnement de Lyon, UMR 5256, Université Lyon 1, CNRS, Villeurbanne, France

Meinrat O. Andreae

76 shared publications

Gerald Wagner

69 shared publications

Andreas Richter

60 shared publications

University of Bremen

John Philip Burrows

40 shared publications

University of Bremen

14
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3
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31
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Publication Record
Distribution of Articles published per year 
(2002 - 2017)
Total number of journals
published in
 
10
 
Publications See all
Article 0 Reads 3 Citations Probing into the aging dynamics of biomass burning aerosol by using satellite measurements of aerosol optical depth and ... Igor B. Konovalov, Matthias Beekmann, Evgeny V. Berezin, Pao... Published: 04 April 2017
Atmospheric Chemistry and Physics, doi: 10.5194/acp-17-4513-2017
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Carbonaceous aerosol released into the atmosphere from open biomass burning (BB) is known to undergo considerable chemical and physical transformations (aging). However, there is substantial controversy about the nature and observable effects of these transformations. A shortage of consistent observational evidence on BB aerosol aging processes under different environmental conditions and at various temporal scales hinders development of their adequate representations in chemistry transport models (CTMs). In this study, we obtain insights into the BB aerosol dynamics by using available satellite measurements of aerosol optical depth (AOD) and carbon monoxide (CO). The basic concept of our method is to consider AOD as a function of the BB aerosol photochemical age (that is, the time period characterizing the exposure of BB aerosol emissions to atmospheric oxidation reactions) predicted by means of model tracers. We evaluate the AOD enhancement ratio (ER) defined as the ratio of optical depth of actual BB aerosol with respect to that of a modeled aerosol tracer that is assumed to originate from the same fires as the real BB aerosol but that is not affected by any aging processes. To limit possible effects of model transport errors, the AOD measurements are normalized to CO column amounts that are also retrieved from satellite measurements. The method is applied to the analysis of the meso- and synoptic-scale evolution of aerosol in smoke plumes from major wildfires that occurred in Siberia in summer 2012. AOD and CO retrievals from MODIS and IASI measurements, respectively, are used in combination with simulations performed with the CHIMERE CTM. The analysis indicates that aging processes strongly affected the evolution of BB aerosol in the situation considered, especially in dense plumes (with spatial average PM2. 5 concentration exceeding 100µgm−3). For such plumes, the ER is found to increase almost 2-fold on the scale of ∼ 10h of daytime aerosol evolution (after a few first hours of the evolution that are not resolved in our analysis). The robustness of this finding is corroborated by sensitivity tests and Monte Carlo experiments. Furthermore, a simulation using the volatility basis set framework suggests that a large part of the increase in the ER can be explained by atmospheric processing of semi-volatile organic compounds. Our results are consistent with findings of a number of earlier studies reporting considerable underestimation of AOD by CTMs in which BB aerosol aging processes have either been disregarded or simulated in a highly simplified way. In general, this study demonstrates the feasibility of using satellite measurements of AOD in biomass burning plumes in combination with aerosol tracer simulations for the investigation of BB aerosol evolution and validation of BB aerosol aging schemes in atmospheric models.
Article 0 Reads 5 Citations Estimation of fossil-fuel CO2 emissions using satellite measurements of "proxy" species Igor B. Konovalov, Evgeny V. Berezin, Philippe Ciais, Grégoi... Published: 01 November 2016
Atmospheric Chemistry and Physics, doi: 10.5194/acp-16-13509-2016
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Fossil-fuel (FF) burning releases carbon dioxide (CO2) together with many other chemical species, some of which, such as nitrogen dioxide (NO2) and carbon monoxide (CO), are routinely monitored from space. This study examines the feasibility of estimation of FF CO2 emissions from large industrial regions by using NO2 and CO column retrievals from satellite measurements in combination with simulations by a mesoscale chemistry transport model (CTM). To this end, an inverse modeling method is developed that allows estimating FF CO2 emissions from different sectors of the economy, as well as the total CO2 emissions, in a given region. The key steps of the method are (1) inferring "top-down" estimates of the regional budget of anthropogenic NOx and CO emissions from satellite measurements of proxy species (NO2 and CO in the case considered) without using formal a priori constraints on these budgets, (2) the application of emission factors (the NOx-to-CO2 and CO-to-CO2 emission ratios in each sector) that relate FF CO2 emissions to the proxy species emissions and are evaluated by using data of "bottom-up" emission inventories, and (3) cross-validation and optimal combination of the estimates of CO2 emission budgets derived from measurements of the different proxy species. Uncertainties in the top-down estimates of the NOx and CO emissions are evaluated and systematic differences between the measured and simulated data are taken into account by using original robust techniques validated with synthetic data. To examine the potential of the method, it was applied to the budget of emissions for a western European region including 12 countries by using NO2 and CO column amounts retrieved from, respectively, the OMI and IASI satellite measurements and simulated by the CHIMERE mesoscale CTM, along with the emission conversion factors based on the EDGAR v4.2 emission inventory. The analysis was focused on evaluation of the uncertainty levels for the top-down NOx and CO emission estimates and "hybrid" estimates (that is, those based on both atmospheric measurements of a given proxy species and respective bottom-up emission inventory data) of FF CO2 emissions, as well as on examining consistency between the FF NO2 emission estimates derived from measurements of the different proxy species. It is found that NO2 measurements can provide much stronger constraints to the total annual FF CO2 emissions in the study region than CO measurements, the accuracy of the NO2-measurement-based CO2 emission estimate being mostly limited by the uncertainty in the top-down NOx emission estimate. Nonetheless, CO measurements are also found to be useful as they provide additional constraints to CO2 emissions and enable evaluation of the hybrid FF CO2 emission estimates obtained from NO2 measurements. Our most reliable estimate for the total annual FF CO2 emissions in the study region in 2008 (2.71±0.30PgCO2) is found to be...
CONFERENCE-ARTICLE 3 Reads 0 Citations Inverse Modeling of Nitrogen Oxides Emissions from the 2010 Russian Wildfires by Using Satellite Measurements of Nitroge... Evgeny Berezin, Igor Konovalov, Yulia Romanova Published: 15 July 2016
The 1st International Electronic Conference on Atmospheric Sciences, doi: 10.3390/ecas2016-B003
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Nitrogen oxides (NOx) play a major role in the atmospheric oxidation processes leading to ozone and secondary organic aerosol formation in the lower atmosphere. Wildfires are one of the important sources of NOx emissions; however, knowledge of NOx emissions from fires is currently insufficient and available estimates provided by emission inventories have mostly not been validated against atmospheric measurements. Recent studies indicated that useful observational constraints to biomass burning (BB) NOx emissions are provided by satellites measurements of nitrogen dioxide (NO2), but available BB NOx emission estimates inferred from such measurements involve quantitative assumptions regarding the atmospheric NOx lifetime. In this study, we investigated NOx emissions from the extreme wildfires that occurred in the European part of Russia in summer 2010. To this end, we analyzed tropospheric NO2 retrievals from measurements performed by the OMI satellite instrument in the framework of an original inverse modeling method. A quantitative relationship between BB NOx emissions and tropospheric NO2 columns was simulated using the mesoscale CHIMERE chemistry transport model. Our analysis indicated that such a relationship depends strongly on BB emissions of volatile organic compounds and that a dependence of the effective NOx lifetime on the NOx fluxes can be essentially nonlinear. Our estimates of the total NOx emissions in the study region are found to be at least 40% larger compared to the respective data from the GFASv1.0 and GFED4.1s global fire emission inventories.

Article 0 Reads 0 Citations Effect of photochemical self-action of carbon-containing aerosol: Wildfires I. B. Konovalov, E. V. Berezin, M. Beekmann Published: 01 May 2016
Izvestiya, Atmospheric and Oceanic Physics, doi: 10.1134/s0001433816030063
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It has been shown by numerical simulation that the rate of formation of secondary organic aerosols (SOAs) in smoke plumes caused by vegetation and peat fires under real conditions can significantly depend on the aerosol optical thickness (AOT). The AOT determines the photodissociation rate and hydroxyl radical concentration, which in turn determines the rate of SOA generation as a result of oxidation of semivolatile organic compounds. Quantitative analysis has been carried out for the situation that took place in European Russia during the 2010 Russian wildfires. The state-of-the-art 3D chemical transport model is used in this study; the simulations are optimized and validated using the data of monitoring of the particulate matter in the Moscow region and Finland. The findings indicate that it is important to allow for this effect in studies focused on the analysis and prediction of air pollution due to wildfires, as well as climate and weather studies, whose results may depend on the assumptions about the content and properties of atmospheric carbon-containing aerosol.
Article 0 Reads 2 Citations Patriotism on the internet: Journalists’ behavior and user comments Avshalom Ginosar, Igor Konovalov Published: 24 September 2015
Media, War & Conflict, doi: 10.1177/1750635215607813
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While a patriotic tendency in traditional journalism has been intensively investigated, there is much less evidence and fewer analyses of the phenomenon regarding online journalism. In this research, three main indicators of patriotic journalism are addressed: adopting governmental framing, expressing solidarity with the community, and ignoring the enemy’s narratives and positions. These indicators are investigated while analyzing online coverage of a confrontation between Israel and Hamas. A total of 192 online news items on three Israeli news websites were analyzed, in addition to 8344 user comments. The findings reveal that journalists behaved in a patriotic manner like their counterparts from the traditional media. However, users thought it was not patriotic enough. The authors argue that while patriotic behavior in traditional journalism has been often considered as deviant from the traditional objective model of journalism, in the online interactive environment, patriotic coverage of national conflicts might be seen as a natural part of the journalistic work.
Article 0 Reads 8 Citations Significant light induced ozone loss on biomass burning aerosol: Evidence from chemistry-transport modeling based on new... I. B. Konovalov, M. Beekmann, B. D'anna, C. George Published: 14 September 2012
Geophysical Research Letters, doi: 10.1029/2012gl052432
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[1] Recent laboratory studies indicated that a photo‐induced heterogeneous reaction of ozone on the surface of aerosol containing humic like substances (HULIS) has the potential to affect the ozone budget in biomass burning plumes. To evaluate atmospheric significance of such heterogeneous light induced ozone loss, this process has been taken into account in the simulation of the extreme air pollution episode in the Moscow region during the 2010 mega fire event in western Russia. Results of the numerical experiments performed with the CHIMERE chemistry transport model indicate that photo induced removal of ozone could lead to significant (reaching several tens of percent) episodic decrease of the ozone concentration. The simulations also show that while wildfires provide reactive surface for the considered reaction, they strongly inhibit the photo‐induced heterogeneous ozone loss by attenuating actinic fluxes through the “shielding” aerosol effect. The present results are calling for additional experimental and modelling studies.