Impact of wild forest fires in Eastern Europe on aerosol composition and particle optical properties

Introduction. Aerosols in the Earth's atmosphere are not only air pollutants but also a factor that affects the climate. The study of the dynamics of aerosol layer properties and aerosol particles properties, and revealing sources of the atmosphere pollution by aerosols is one of the urgent problems of modern environmental sciences. Monitoring of the air pollution caused by aerosols contributes to the determination of its effects on the climate and to the reduction of its negative impacts on the health of the population. The purpose of this paper is to present the analysis of the dynamics of aerosols in the atmosphere over Eastern Europe. Thus, latest technologies and approaches are used: remote ground-based measurements of the optical properties of aerosol particles with the international sun photometers network AERONET; analysis of fires distribution during summer 2010 with the data application from satellite instrument MODIS; atmospheric dynamics research with the analysis of synoptic situation and modeling of transport of particles with the application of HYSPLIT model. Results. The peculiarities of changes of aerosol optical depth at 500 nm spectral channel and Angstrom parameter 440-870 nm for 10 AERONET stations in Eastern Europe are discussed in the article. The authors provide complex analysis of aerosols distribution together with natural processes as forest fires and overview these processes considering weather conditions that were conducive for aerosols accumulation during that time. HYSPLIT back trajectories for mentioned stations in the altitude 0.5, 1.5, 3, 4 and 5 km are used as the improvement of results of synoptic analysis. Clear advantage of modelling of transport processes give the ability to receive detailed transport paths, which makes easier to distinguish the origin of aerosols. Conclusion. Detailed research of aerosols with the application of up-to-date technologies makes the analysis of the optical properties of aerosols over large area quite efficient. The obvious effect of forest fires in European territory of Russia (UTR) on air quality of observational stations of Ukraine, Russia, Moldova, Romania, Poland, Belarus and Estonia is detected and analysed. The further application of satellite measurements of optical properties of aerosols are attempted to be implemented to the further research.

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Aerosol chemical and optical properties over the Paris area within ESQUIF project

Atmospheric Chemistry and Physics ◽

10.5194/acp-6-3257-2006 ◽

2006 ◽

Vol 6 (11) ◽

pp. 3257-3280 ◽

Cited By ~ 29

Author(s):

A. Hodzic ◽

R. Vautard ◽

P. Chazette ◽

L. Menut ◽

B. Bessagnet

Keyword(s):

Optical Properties ◽

Secondary Organic Aerosols ◽

Organic Aerosols ◽

Dust Particles ◽

Aerosol Size Distribution ◽

Aerosol Composition ◽

Aerosol Mass ◽

Coarse Mode ◽

Paris Area ◽

Flight Trajectories

Abstract. Aerosol chemical and optical properties are extensively investigated for the first time over the Paris Basin in July 2000 within the ESQUIF project. The measurement campaign offers an exceptional framework to evaluate the performances of the chemistry-transport model CHIMERE in simulating concentrations of gaseous and aerosol pollutants, as well as the aerosol-size distribution and composition in polluted urban environments against ground-based and airborne measurements. A detailed comparison of measured and simulated variables during the second half of July with particular focus on 19 and 31 pollution episodes reveals an overall good agreement for gas-species and aerosol components both at the ground level and along flight trajectories, and the absence of systematic biases in simulated meteorological variables such as wind speed, relative humidity and boundary layer height as computed by the MM5 model. A good consistency in ozone and NO concentrations demonstrates the ability of the model to reproduce the plume structure and location fairly well both on 19 and 31 July, despite an underestimation of the amplitude of ozone concentrations on 31 July. The spatial and vertical aerosol distributions are also examined by comparing simulated and observed lidar vertical profiles along flight trajectories on 31 July and confirm the model capacity to simulate the plume characteristics. The comparison of observed and modeled aerosol components in the southwest suburb of Paris during the second half of July indicates that the aerosol composition is rather correctly reproduced, although the total aerosol mass is underestimated by about 20%. The simulated Parisian aerosol is dominated by primary particulate matter that accounts for anthropogenic and biogenic primary particles (40%), and inorganic aerosol fraction (40%) including nitrate (8%), sulfate (22%) and ammonium (10%). The secondary organic aerosols (SOA) represent 12% of the total aerosol mass, while the mineral dust accounts for 8%. The comparison demonstrates the absence of systematic errors in the simulated sulfate, ammonium and nitrates total concentrations. However, for nitrates the observed partition between fine and coarse mode is not reproduced. In CHIMERE there is a clear lack of coarse-mode nitrates. This calls for additional parameterizations in order to account for the heterogeneous formation of nitrate onto dust particles. Larger discrepancies are obtained for the secondary organic aerosols due to both inconsistencies in the SOA formation processes in the model leading to an underestimation of their mass and large uncertainties in the determination of the measured aerosol organic fraction. The observed mass distribution of aerosols is not well reproduced, although no clear explanation can be given.

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Aerosol composition and related optical properties in the marine boundary layer over the Baltic Sea

Journal of Aerosol Science ◽

10.1016/s0021-8502(00)00122-1 ◽

2001 ◽

Vol 32 (8) ◽

pp. 933-955 ◽

Cited By ~ 12

Author(s):

J Kuśmierczyk-Michulec ◽

M Schulz ◽

S Ruellan ◽

O Krüger ◽

E Plate ◽

...

Keyword(s):

Boundary Layer ◽

Optical Properties ◽

Baltic Sea ◽

Marine Boundary Layer ◽

The Baltic Sea ◽

Aerosol Composition ◽

The Baltic

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Aerosol chemical and optical properties over the Paris area within ESQUIF project

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-6-401-2006 ◽

2006 ◽

Vol 6 (1) ◽

pp. 401-454 ◽

Cited By ~ 3

Author(s):

A. Hodzic ◽

R. Vautard ◽

P. Chazette ◽

L. Menut ◽

B. Bessagnet

Keyword(s):

Optical Properties ◽

Secondary Organic Aerosols ◽

Organic Aerosols ◽

Dust Particles ◽

Aerosol Size Distribution ◽

Aerosol Composition ◽

Aerosol Mass ◽

Coarse Mode ◽

Paris Area ◽

Flight Trajectories

Abstract. Aerosol chemical and optical properties are extensively investigated for the first time over the Paris Basin in July 2000 within the ESQUIF project. The measurement campaign offers an exceptional framework to evaluate the performances of the chemistry-transport model CHIMERE in simulating concentrations of gaseous and aerosol pollutants, as well as the aerosol-size distribution and composition in polluted urban environment against ground-based and airborne measurements. A detailed comparison of measured and simulated variables during the second half of July with particular focus on 19 and 31 pollution episodes reveals an overall good agreement for gas-species and aerosol components both at the ground level and along flight trajectories, and the absence of systematic biases in simulated meteorological variables such as wind speed, relative humidity and boundary layer height as computed by the MM5 model. A good consistency in ozone and NO concentrations demonstrates the ability of the model to reproduce fairly well the plume structure and location both on 19 and 31 July, despite an underestimation of the amplitude of ozone concentrations on 31 July. The spatial and vertical aerosol distributions are also examined by comparing simulated and observed lidar vertical profiles along flight trajectories on 31 July and confirmed the model capacity to simulate the plume characteristics. The comparison of observed and modeled aerosol components in the southwest suburb of Paris during the second half of July indicated that the aerosol composition is rather correctly reproduced, although the total aerosol mass is underestimated of about 20%. The simulated Parisian aerosol is dominated by primary particulate matter that accounts for anthropogenic and biogenic primary particles (40%) and inorganic aerosol fraction (40%) including nitrate (8%), sulfate (22%) and ammonium (10%). The secondary organic aerosols (SOA) represent 12% of the total aerosol mass, while the mineral dust accounts for 8%. The comparison demonstrated the absence of systematic errors in the simulated sulfate, ammonium and nitrates total concentrations. However for nitrates the observed partition between fine and coarse mode is not reproduced. In CHIMERE there is a clear lack of coarse-mode nitrates. This calls for additional parameterizations in order to account for the heterogeneous formation of nitrate onto dust particles. Larger discrepancies are obtained for the secondary organic aerosols due to both inconsistencies in the SOA formation processes in the model leading to an underestimation of their mass and large uncertainties in the determination of the measured aerosol organic fraction. The observed mass distribution of aerosols is not well reproduced, although no clear explanation can be given.

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Optical properties of atmospheric fine particles near Beijing during the HOPE-J<sup>3</sup>A Campaign

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-15-33675-2015 ◽

2015 ◽

Vol 15 (22) ◽

pp. 33675-33730

Author(s):

X. Xu ◽

W. Zhao ◽

Q. Zhang ◽

S. Wang ◽

B. Fang ◽

...

Keyword(s):

Refractive Index ◽

Optical Properties ◽

Fine Particles ◽

Complex Refractive Index ◽

Single Scattering ◽

Single Scattering Albedo ◽

Organic Mass ◽

Absorption Coefficients ◽

Aerosol Composition ◽

Inorganic Species

Abstract. The optical properties and chemical composition of PM1.0 (particulate with an aerodynamic diameter of less than 1.0 μm) particles in a suburban environment (Huairou) near the mega-city Beijing were measured during the HOPE-J3A (Haze Observation Project Especially for Jing-Jin-Ji Area) field campaign. The campaign covered the period November 2014 to January 2015 during the winter coal heating season. The average and standard deviations for the extinction, scattering, absorption coefficients, and the aerosol single scattering albedo (SSA) at λ = 470 nm during the measurement period were 201 ± 240, 164 ± 202, 37 ± 43 Mm-1, and 0.80 ± 0.08, respectively. The mean mass scattering (MSE) and absorption (MAE) efficiencies were 4.77 ± 0.01 and 0.87 ± 0.03 m2g-1, respectively. Highly time-resolved air pollution episodes clearly show the dramatic evolution of the PM1.0 size distribution, extensive optical properties (extinction, scattering, and absorption coefficients) and intensive optical properties (single scattering albedo and complex refractive index) during haze formation, development and decline. Time periods were classified into three different pollution levels (clear, slightly polluted, and polluted) for further analysis. It was found that: (1) The diurnal patterns of the aerosol extinction, scattering, absorption coefficients, and SSA differed for the three pollution classes. (2) The real and imaginary part of complex refractive index (CRI) increased, while the SSA decreased from clear to polluted days. (3) The relative contributions of organic and inorganic species to observed aerosol composition changed significantly from clear to polluted days: the organic mass fraction decreased (50 to 43 %) while the proportion of sulfates, nitrates, and ammonium increased strongly (34 to 44 %). (4) The fractional contribution of chemical components to extinction coefficients was calculated by using the modified IMPROVE algorithm. Organic mass was the largest contributor (58 %) to the total extinction of PM1.0. When the air quality deteriorated, the change of the relative contribution of sulfate aerosol to the total extinction was small, but the contribution of nitrate aerosol increased significantly (from 17 % on clear days to 23 % on polluted days). (5) The observed mass scattering efficiencies increased consistently with the pollution extent, however, the observed mass absorption efficiencies increased consistently with increasing mass concentration in slightly pollution conditions, but decreased under polluted conditions.

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Benefit of depolarization ratio at λ = 1064 nm for the retrieval of the aerosol microphysics from lidar measurements

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-7-5095-2014 ◽

2014 ◽

Vol 7 (5) ◽

pp. 5095-5115

Author(s):

J. Gasteiger ◽

V. Freudenthaler

Keyword(s):

Optical Properties ◽

Mass Concentration ◽

Single Scattering ◽

Sufficient Information ◽

Depolarization Ratio ◽

Aerosol Composition ◽

Microphysical Properties ◽

Lidar Measurements ◽

Increased Sensitivity ◽

Linear Depolarization Ratio

Abstract. A better quantification of aerosol microphysical and optical properties is required to improve the modelling of aerosol effects on weather and climate. This task is methodologically demanding due to the huge diversity of aerosol composition and of their shape and size distribution, and due to the complexity of the relation between the microphysical and optical properties. Lidar remote sensing is a valuable tool to gain spatially and temporally resolved information on aerosol properties. Advanced lidar systems provide sufficient information on the aerosol optical properties for the retrieval of important aerosol microphysical properties. Recently, the mass concentration of transported volcanic ash, which is relevant for the flight safety of airplanes, was retrieved from measurements of such lidar systems in Southern Germany. The relative uncertainty of the retrieved mass concentration was on the order of ±50%. The present study investigates improvements of the retrieval accuracy when the capability of measuring the linear depolarization ratio at 1064 nm is added to the lidar setup. The lidar setups under investigation are based on the setup of MULIS and POLIS of the LMU in Munich which measure the linear depolarization ratio at 355 nm and 532 nm with high accuracy. By comparing results of retrievals applied to simulated lidar measurements with and without the depolarization at 1064 nm it is found that the availability of 1064 nm depolarization measurements reduces the uncertainty of the retrieved mass concentration and effective particle size by a factor of about 2–3. This significant improvement in accuracy is the result of the increased sensitivity of the lidar setup to larger particles. However, the retrieval of the single scattering albedo, which is relevant for the radiative transfer in aerosol layers, does hardly benefit from the availability of 1064 nm depolarization measurements.

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Lidar profiling of aerosol optical properties from Paris to Lake Baikal (Siberia)

Atmospheric Chemistry and Physics ◽

10.5194/acp-15-5007-2015 ◽

2015 ◽

Vol 15 (9) ◽

pp. 5007-5026 ◽

Cited By ~ 19

Author(s):

E. Dieudonné ◽

P. Chazette ◽

F. Marnas ◽

J. Totems ◽

X. Shang

Keyword(s):

Optical Properties ◽

Lake Baikal ◽

Forest Fires ◽

Western Europe ◽

Lower Boundary ◽

Aerosol Optical Properties ◽

Imaging Spectrometer ◽

Moderate Resolution ◽

The Difference ◽

First Time

Abstract. In June 2013, a ground-based mobile lidar performed the ~10 000 km ride from Paris to Ulan-Ude, near Lake Baikal, profiling for the first time aerosol optical properties all the way from western Europe to central Siberia. The instrument was equipped with N2-Raman and depolarization channels that enabled an optical speciation of aerosols in the low and middle troposphere. The extinction-to-backscatter ratio (also called lidar ratio or LR) and particle depolarization ratio (PDR) at 355 nm have been retrieved. The LR in the lower boundary layer (300–700 m) was found to be 63 ± 17 sr on average during the campaign with a distribution slightly skewed toward higher values that peaks between 50 and 55 sr. Although the difference is small, PDR values observed in Russian cities (>2%, except after rain) are systematically higher than the ones measured in Europe (<1%), which is probably an effect of the lifting of terrigenous aerosols by traffic on roads. Biomass burning layers from grassland or/and forest fires in southern Russia exhibit LR values ranging from 65 to 107 sr and from 3 to 4% for the PDR. During the route, desert dust aerosols originating from the Caspian and Aral seas regions were characterized for the first time, with a LR (PDR) of 43 ± 14 sr (23 ± 2%) for pure dust. The lidar observations also showed that this dust event extended over 2300 km and lasted for ~6 days. Measurements from the Moderate Resolution Imaging Spectrometer (MODIS) show that our results are comparable in terms of aerosol optical thickness (between 0.05 and 0.40 at 355 nm) with the mean aerosol load encountered throughout our route.

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Direct radiative effect of the Russian wildfires and its impact on air temperature and atmospheric dynamics during August 2010

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-1999-2014 ◽

2014 ◽

Vol 14 (4) ◽

pp. 1999-2013 ◽

Cited By ~ 34

Author(s):

J. C. Péré ◽

B. Bessagnet ◽

M. Mallet ◽

F. Waquet ◽

I. Chiapello ◽

...

Keyword(s):

Optical Properties ◽

Wind Speed ◽

Eastern Europe ◽

Air Temperature ◽

Air Entrainment ◽

Atmospheric Dynamics ◽

Horizontal Wind ◽

Satellite Measurements ◽

Near Surface ◽

Aerosol Plume

Abstract. In this study, we investigate the shortwave aerosol direct radiative forcing (ADRF) and its feedback on air temperature and atmospheric dynamics during a major fire event that occurred in Russia during August 2010. The methodology is based on an offline coupling between the CHIMERE chemistry-transport and the Weather Research and Forecasting (WRF) models. First, simulations for the period 5–12 August 2010 have been evaluated by using AERONET (AErosol RObotic NETwork) and satellite measurements of the POLarization and Directionality of the Earth's Reflectance (POLDER) and the Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) sensors. During this period, elevated POLDER aerosol optical thickness (AOT) is found over a large part of eastern Europe, with values above 2 (at 550 nm) in the aerosol plume. According to CALIOP observations, particles remain confined to the first five kilometres of the atmospheric layer. Comparisons with satellite measurements show the ability of CHIMERE to reproduce the regional and vertical distribution of aerosols during their transport from the source region. Over Moscow, AERONET measurements indicate an important increase of AOT (340 nm) from 0.7 on 5 August to 2–4 between 6 and 10 August when the aerosol plume was advected over the city. Particles are mainly observed in the fine size mode (radius in the range 0.2–0.4 μm) and are characterized by elevated single-scattering albedo (SSA) (0.95–0.96 between 440 and 1020 nm). Comparisons of simulations with AERONET measurements show that aerosol physical–optical properties (size distribution, AOT, SSA) have been well simulated over Moscow in terms of intensity and/or spectral dependence. Secondly, modelled aerosol optical properties have been used as input in the radiative transfer code of WRF to evaluate their direct radiative impact. Simulations indicate a significant reduction of solar radiation at the ground (up to 80–150 W m−2 in diurnal averages over a large part of eastern Europe due to the presence of the aerosol plume. This ADRF causes an important reduction of the near-surface air temperature between 0.2 and 2.6° on a regional scale. Moscow has been affected by the aerosol plume, especially between 6 and 10 August. During this period, aerosol causes a significant reduction of surface shortwave radiation (up to 70–84 W m−2 in diurnal averages) with a moderate part (20–30%) due to solar absorption within the aerosol layer. The resulting feedbacks lead to a cooling of the air up to 1.6° at the surface and 0.1° at an altitude of 1500–2000 m (in diurnal averages), that contribute to stabilize the atmospheric boundary layer (ABL). Indeed, a reduction of the ABL height of 13 to 65% has been simulated during daytime in presence of aerosols. This decrease is the result of a lower air entrainment as the vertical wind speed in the ABL is shown to be reduced by 5 to 80% (at midday) when the feedback of the ADRF is taken into account. However, the ADRF is shown to have a lower impact on the horizontal wind speed, suggesting that the dilution of particles would be mainly affected by the weakening of the ABL development and associated vertical entrainment. Indeed, CHIMERE simulations driven by the WRF meteorological fields including this ADRF feedback result in a large increase in the modelled near-surface PM10 concentrations (up to 99%). This is due to their lower vertical dilution in the ABL, which tend to reduce model biases with the ground PM10 values observed over Moscow during this specific period.

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