Impact of Long-Range Transport Biomass Burning (BB) Emissions on Cloud Condensation Nuclei (CCN) Activation in Continental Polluted Air of Delhi, India

2020 ◽  
Author(s):  
Subha S. Raj ◽  
Mira L. Pӧhlker ◽  
Thomas Klimach ◽  
Jan-David Förster ◽  
David Walter ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Diurnal Variation ◽  
Long Range ◽  
Biomass Burning ◽  
Mass Fraction ◽  
Cloud Condensation Nuclei ◽  
Average Concentration ◽  
Long Range Transport ◽  
Organic Mass ◽  
Range Transport

<p>Cloud Condensation Nuclei (CCN) and other aerosol properties were investigated in Delhi, India, from Feb. to Mar. 2018. The high anthropogenic influence on aerosol was studied with size-resolved CCN measurements (supersaturation (<em>S</em>) between 0.13 to 0.66% and selected diameters from 10 to 300 nm). Furthermore the chemical composition (Aerosol Chemical Speciation Monitor and Aethalometer AE33) of the particles was measured. The aerosol number size distribution was derived by size data inversion of Differential Mobility Particle Sizer (DMPS) from size-resolved CCN measurements. Based on multi-year back trajectory (BT) data, a spatial clustering analysis was done for the actual campaign period and two distinct clusters were identified: northwest- west northwest-long range transport (NW-LRT) and south-southeast-east southeast (SE).</p><p>There was preponderant organic mass fraction (<em>f</em><sub>org)</sub> in the aerosols throughout the campaign, with prominent diurnal variation except during the SE period. Pronounced diurnal variation was observed also in black carbon (BC) with an average concentration of 16 <em>µ</em>g/m<sup>3</sup> during NW-LRT, in contrast to a weak diurnal cycle with lower average concentration of 8 <em>µ</em>g/m<sup>3</sup> during SE. During the NW-LRT cluster the air masses traversed over agriculture fields with biomass burning (BB) activities identified using the fire radiative power (FRP) observations of Copernicus Atmosphere Monitoring Service (CAMS) Global Fire Assimilation System (GFAS). So it can be speculated that the BB emissions from the fields have contributed to enhanced BC concentrations during this period over Delhi. The remaining period, showing a mixture of local and long-range transported emissions also had a BC concentration higher than SE period when only local/regional emissions were observed. This is an important insight into the air pollution apocalypse in Delhi.</p><p>The overall average values of critical dry diameter (<em>D</em><sub>c</sub>) for CCN activation varied from 54 ± 8 nm at <em>S</em> = 0.66% to 139 ± 12 nm at <em>S</em> = 0.13%.The hygroscopicity parameter derived from CCN data (<em>к</em><sub>CCN</sub>) was in the range from 0.1 to 0.9 with an arithmetic mean of 0.27 ± 0.10, which is close to that of Beijing, another polluted continental region (0.31 ± 0.08, Gunthe et al., 2011). <em>к</em><sub>CCN</sub> also shows good agreement with the hygroscopicity parameter derived from the chemical composition measurements. A linear fit (Gunthe et al., 2009) applied to the relationship between refractory/non-refractory organic mass fraction and <em>к</em><sub>CCN </sub>at <em>S</em> = 0.13%, gives an effective hygroscopicity parameter <em>к</em><sub>org</sub> = 0.17 ± 0.09 and <em>к</em><sub>inorg</sub> = 0.80 ± 0.09, when extrapolated to <em>f</em><sub>org</sub> = 1 and <em>f</em><sub>org</sub> = 0, respectively. The presence of externally mixed inactive CCN particles is indicated by an average maximum activated fraction (<em>MAF</em>) of 0.82 ± 0.17 at <em>S</em> = 0.13%. The overall average <em>D</em><sub>c</sub>, <em>к</em><sub>CCN</sub>, and <em>MAF </em>did not vary much between NW-LRT and SE periods, although the particle number concentration was higher during NW-LRT. Moreover, high CCN efficiency was observed during NW-LRT, in spite of its enhanced BC concentration, indicating the presence of aged internally mixed aerosols. Further details will be presented.</p>

scholarly journals Long-term observations of cloud condensation nuclei over the Amazon rain forest – Part 2: Variability and characteristics of biomass burning, long-range transport, and pristine rain forest aerosols

2018 ◽  
Vol 18 (14) ◽  
pp. 10289-10331 ◽  
Author(s):  
Mira L. Pöhlker ◽  
Florian Ditas ◽  
Jorge Saturno ◽  
Thomas Klimach ◽  
Isabella Hrabě de Angelis ◽  
...  
Keyword(s):  
Water Vapor ◽  
Long Range ◽  
Biomass Burning ◽  
Rain Forest ◽  
Cloud Condensation Nuclei ◽  
Long Range Transport ◽  
Accumulation Mode ◽  
Range Transport ◽  
Mass Fractions ◽  
Vapor Supersaturation

Abstract. Size-resolved measurements of atmospheric aerosol and cloud condensation nuclei (CCN) concentrations and hygroscopicity were conducted over a full seasonal cycle at the remote Amazon Tall Tower Observatory (ATTO, March 2014–February 2015). In a preceding companion paper, we presented annually and seasonally averaged data and parametrizations (Part 1; Pöhlker et al., 2016a). In the present study (Part 2), we analyze key features and implications of aerosol and CCN properties for the following characteristic atmospheric conditions: Empirically pristine rain forest (PR) conditions, where no influence of pollution was detectable, as observed during parts of the wet season from March to May. The PR episodes are characterized by a bimodal aerosol size distribution (strong Aitken mode with DAit ≈ 70 nm and NAit ≈ 160 cm−3, weak accumulation mode with Dacc ≈ 160 nm and Nacc≈ 90 cm−3), a chemical composition dominated by organic compounds, and relatively low particle hygroscopicity (κAit≈ 0.12, κacc ≈ 0.18). Long-range-transport (LRT) events, which frequently bring Saharan dust, African biomass smoke, and sea spray aerosols into the Amazon Basin, mostly during February to April. The LRT episodes are characterized by a dominant accumulation mode (DAit ≈ 80 nm, NAit ≈ 120 cm−3 vs. Dacc ≈ 180 nm, Nacc ≈ 310 cm−3), an increased abundance of dust and salt, and relatively high hygroscopicity (κAit≈ 0.18, κacc ≈ 0.35). The coarse mode is also significantly enhanced during these events. Biomass burning (BB) conditions characteristic for the Amazonian dry season from August to November. The BB episodes show a very strong accumulation mode (DAit ≈ 70 nm, NAit ≈ 140 cm−3 vs. Dacc ≈ 170 nm, Nacc ≈ 3400 cm−3), very high organic mass fractions (∼ 90 %), and correspondingly low hygroscopicity (κAit≈ 0.14, κacc ≈ 0.17). Mixed-pollution (MPOL) conditions with a superposition of African and Amazonian aerosol emissions during the dry season. During the MPOL episode presented here as a case study, we observed African aerosols with a broad monomodal distribution (D ≈ 130 nm, NCN,10 ≈ 1300 cm−3), with high sulfate mass fractions (∼ 20 %) from volcanic sources and correspondingly high hygroscopicity (κ< 100 nm ≈ 0.14, κ>100nm≈ 0.22), which were periodically mixed with fresh smoke from nearby fires (D ≈ 110 nm, NCN,10 ≈ 2800 cm−3) with an organic-dominated composition and sharply decreased hygroscopicity (κ<150nm≈ 0.10, κ>150nm≈ 0.20). Insights into the aerosol mixing state are provided by particle hygroscopicity (κ) distribution plots, which indicate largely internal mixing for the PR aerosols (narrow κ distribution) and more external mixing for the BB, LRT, and MPOL aerosols (broad κ distributions). The CCN spectra (CCN concentration plotted against water vapor supersaturation) obtained for the different case studies indicate distinctly different regimes of cloud formation and microphysics depending on aerosol properties and meteorological conditions. The measurement results suggest that CCN activation and droplet formation in convective clouds are mostly aerosol-limited under PR and LRT conditions and updraft-limited under BB and MPOL conditions. Normalized CCN efficiency spectra (CCN divided by aerosol number concentration plotted against water vapor supersaturation) and corresponding parameterizations (Gaussian error function fits) provide a basis for further analysis and model studies of aerosol–cloud interactions in the Amazon.

scholarly journals Effects of continental emissions on cloud condensation nuclei (CCN) activity in the northern South China Sea during summertime 2018

2020 ◽  
Vol 20 (15) ◽  
pp. 9153-9167 ◽  
Author(s):  
Mingfu Cai ◽  
Baoling Liang ◽  
Qibin Sun ◽  
Shengzhen Zhou ◽  
Xiaoyang Chen ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Long Range ◽  
Particle Number ◽  
Cloud Condensation Nuclei ◽  
Northern South China Sea ◽  
Long Range Transport ◽  
Marine Atmosphere ◽  
Condensation Nuclei ◽  
Air Masses ◽  
Range Transport

Abstract. Aerosol particles in marine atmosphere have been shown to significantly affect cloud formation, atmospheric optical properties, and climate change. However, high temporally and spatially resolved atmospheric measurements over the sea are currently sparse, limiting our understanding of aerosol properties in marine atmosphere. In this study, a ship-based cruise campaign was conducted over the northern South China Sea (SCS) region during summertime 2018. The chemical composition of non-refractory PM1 (NR-PM1), the particle number size distribution (PNSD), and size-resolved cloud condensation nuclei (CCN) activity were measured by a time-of-flight aerosol chemical speciation monitor (ToF-ACSM) and the combination of a cloud condensation nuclei counter (CCNc) and a scanning mobility particle sizer (SMPS). Overall, aerosol particles exhibited a unimodal distribution centering at 60–80 nm and the chemical composition of the NR-PM1 was dominated by sulfate (∼ 46 %), which likely originated from anthropogenic emissions rather than dimethyl sulfide (DMS) oxidation. Two polluted episodes (P1 and P2) were observed, and both were characterized by high particle number concentrations (NCN) which originated from local emissions and from emissions in inland China via long-range transport. The concentrations of trace gases (i.e., O3, CO, NOx) and particles (NCN and NCCN at ss = 0.34 %) were elevated during P2 at the end of the campaign and decreased with offshore distance, further suggesting important impacts of anthropogenic emissions from the inland Pearl River Delta (PRD) region. Two relatively clean periods (C1 and C2) prior to and after tropical storm Bebinca were classified and the air was affected by air masses from the southwest and from the Indo-Chinese Peninsula, respectively. Chemical composition measurements showed an increase in organic mass fraction during P2 compared to C2; however, no obviously different κ values were obtained from the CCNc measurements, implying that the air masses carried pollutants from local sources during long-range transport. We report an average value of about 0.4 for the aerosol hygroscopicity parameter κ, which falls within the literature values (i.e., 0.2–1.0) for urban and remote marine atmosphere. In addition, our results showed that the CCN fraction (NCCN∕NCN, tot) and the κ values had no clear correlation either with the offshore distance or with concentrations of the particles. Our study highlights dynamical variations in particle properties and the impact of long-range transport from continental China and the Indo-Chinese Peninsula on the northern SCS region during summertime.

Impact of field biomass burning on local pollution and long-range transport of PM2.5 in Northeast Asia

2019 ◽  
Vol 244 ◽  
pp. 414-422 ◽  
Author(s):  
Katsushige Uranishi ◽  
Fumikazu Ikemori ◽  
Hikari Shimadera ◽  
Akira Kondo ◽  
Seiji Sugata
Keyword(s):  
Long Range ◽  
Biomass Burning ◽  
Northeast Asia ◽  
Long Range Transport ◽  
Local Pollution ◽  
Range Transport

scholarly journals Tropospheric CO vertical profiles measured by IAGOS aircraft in 2002&ndash;2017 and the role of biomass burning

2018 ◽  
pp. 1-41
Author(s):  
Hervé Petetin ◽  
Bastien Sauvage ◽  
Mark Parrington ◽  
Hannah Clark ◽  
Alain Fontaine ◽  
...  
Keyword(s):  
East Asia ◽  
Long Range ◽  
Biomass Burning ◽  
South India ◽  
Long Range Transport ◽  
Anthropogenic Emissions ◽  
South East Asia ◽  
Vertical Profiles ◽  
Range Transport

<p><strong>Abstract.</strong> This study investigates the role of biomass burning and long-range transport in the anomalies of carbon monoxide (CO) regularly observed along the tropospheric vertical profiles measured in the framework of IAGOS. Considering the high interannual variability of biomass burning emissions and the episodic nature of pollution long-range transport, one strength of this study is the amount of data taken into account, namely 30,000 vertical profiles at 9 clusters of airports in Europe, North America, Asia, India and southern Africa over the period 2002&amp;ndash;2017. </p> <p> As a preliminary, a brief overview of the spatio-temporal variability, latitudinal distribution, interannual variability and trends of biomass burning CO emissions from 14 regions is provided. The distribution of CO mixing ratios at different levels of the troposphere is also provided based on the entire IAGOS database (125 million CO observations). </p> <p> This study focuses on the free troposphere (altitudes above 2<span class="thinspace"></span>km) where the long-range transport of pollution is favoured. Anomalies at a given airport cluster are here defined as departures from the local seasonally-averaged climatological vertical profile. The intensity of these anomalies varies significantly depending on the airport, with maximum (minimum) CO anomalies of 110&amp;ndash;150 (48)<span class="thinspace"></span>ppbv in Asia (Europe). Looking at the seasonal variation of the frequency of occurrence, the 25<span class="thinspace"></span>% strongest CO anomalies appears reasonably well distributed along the year, in contrast to the 5<span class="thinspace"></span>% or 1<span class="thinspace"></span>% strongest anomalies that exhibit a strong seasonality with for instance more frequent anomalies during summertime in northern United-States, during winter/spring in Japan, during spring in South-east China, during the non-monsoon seasons in south-east Asia and south India, and during summer/fall at Windhoek, Namibia. Depending on the location, these strong anomalies are observed in different parts of the free troposphere. </p> <p> In order to investigate the role of biomass burning emissions in these anomalies, we used the SOFT-IO v1.0 IAGOS added-value products that consist of FLEXPART 20-days backward simulations along all IAGOS aircraft trajectories, coupled with anthropogenic (MACCity) and biomass burning (GFAS) CO emission inventories and vertical injections. SOFT-IO estimates the contribution (in ppbv) of the recent (less than 20 days) primary worldwide CO emissions, tagged per source region. Biomass burning emissions are found to play an important role in the strongest CO anomalies observed at most airport clusters. The regional tags indicate a large contribution from boreal regions at airport clusters in Europe and North America during summer season. In both Japan and south India, the anthropogenic emissions dominate all along the year, except for the strongest summertime anomalies observed in Japan that are due to Siberian fires. The strongest CO anomalies at airport clusters located in south-east Asia are induced by fires burning during spring in south-east Asia and during fall in equatorial Asia. In southern Africa, the Windhoek airport was mainly impacted by fires in southern hemisphere Africa and South America. </p> <p> To our knowledge, no other studies have used such a large dataset of in situ vertical profiles for deriving a climatology of the impact of biomass burning versus anthropogenic emissions on the strongest CO anomalies observed in the troposphere, in combination with information on the source regions. This study therefore provides both qualitative and quantitative information for interpreting the highly variable CO vertical distribution in several regions of interest.</p>

scholarly journals Insights into the aging of biomass burning aerosol from satellite observations and 3D atmospheric modeling: evolution of the aerosol optical properties in Siberian wildfire plumes

2021 ◽  
Vol 21 (1) ◽  
pp. 357-392
Author(s):  
Igor B. Konovalov ◽  
Nikolai A. Golovushkin ◽  
Matthias Beekmann ◽  
Meinrat O. Andreae
Keyword(s):  
Optical Properties ◽  
Long Range ◽  
Biomass Burning ◽  
Organic Aerosol ◽  
Satellite Observations ◽  
Long Range Transport ◽  
Aerosol Optical Properties ◽  
Smoke Plumes ◽  
Range Transport ◽  
Aerosol Aging

Abstract. Long-range transport of biomass burning (BB) aerosol from regions affected by wildfires is known to have a significant impact on the radiative balance and air quality in receptor regions. However, the changes that occur in the optical properties of BB aerosol during long-range transport events are insufficiently understood, limiting the adequacy of representations of the aerosol processes in chemistry transport and climate models. Here we introduce a framework to infer and interpret changes in the optical properties of BB aerosol from satellite observations of multiple BB plumes. Our framework includes (1) a procedure for analysis of available satellite retrievals of the absorption and extinction aerosol optical depths (AAOD and AOD) and single-scattering albedo (SSA) as a function of the BB aerosol photochemical age and (2) a representation of the AAOD and AOD evolution with a chemistry transport model (CTM) involving a simplified volatility basis set (VBS) scheme with a few adjustable parameters. We apply this framework to analyze a large-scale outflow of BB smoke plumes from Siberia toward Europe that occurred in July 2016. We use AAOD and SSA data derived from OMI (Ozone Monitoring Instrument) satellite measurements in the near-UV range along with 550 nm AOD and carbon monoxide (CO) columns retrieved from MODIS (Moderate Resolution Imaging Spectroradiometer) and IASI (Infrared Atmospheric Sounding Interferometer) satellite observations, respectively, to infer changes in the optical properties of Siberian BB aerosol due to its atmospheric aging and to get insights into the processes underlying these changes. Using the satellite data in combination with simulated data from the CHIMERE CTM, we evaluate the enhancement ratios (EnRs) that allow isolating AAOD and AOD changes due to oxidation and gas–particle partitioning processes from those due to other processes, including transport, deposition, and wet scavenging. The behavior of EnRs for AAOD and AOD is then characterized using nonlinear trend analysis. It is found that the EnR for AOD strongly increases (by about a factor of 2) during the first 20–30 h of the analyzed evolution period, whereas the EnR for AAOD does not exhibit a statistically significant increase during this period. The increase in AOD is accompanied by a statistically significant enhancement of SSA. Further BB aerosol aging (up to several days) is associated with a strong decrease in EnRs for both AAOD and AOD. Our VBS simulations constrained by the observations are found to be more consistent with satellite observations of strongly aged BB plumes than “tracer” simulations in which atmospheric transformations of BB organic aerosol were disregarded. The simulation results indicate that the upward trends in EnR for AOD and in SSA are mainly due to atmospheric processing of secondary organic aerosol (SOA), leading to an increase in the mass scattering efficiency of BB aerosol. Evaporation and chemical fragmentation of the SOA species, part of which is assumed to be absorptive (to contain brown carbon), are identified as likely reasons for the subsequent decrease in the EnR for both AAOD and AOD. Hence, our analysis reveals that the long-range transport of smoke plumes from Siberian fires is associated with major changes in BB aerosol optical properties and chemical composition. Overall, this study demonstrates the feasibility of using available satellite observations for evaluating and improving representations in atmospheric models of the BB aerosol aging processes in different regions of the world at much larger temporal scales than those typically addressed in aerosol chamber experiments.

scholarly journals Long-range Transport of Aerosols from Biomass Burning over Southeastern South America and their Implications on Air Quality

2018 ◽  
Vol 18 (7) ◽  
pp. 1734-1745 ◽  
Author(s):  
Leila Droprinchinski Martins ◽  
Ricardo Hallak ◽  
Rafaela Cruz Alves ◽  
Daniela S. de Almeida ◽  
Rafaela Squizzato ◽  
...  
Keyword(s):  
Air Quality ◽  
South America ◽  
Long Range ◽  
Biomass Burning ◽  
Long Range Transport ◽  
Range Transport

scholarly journals Long range transport and mixing of aerosol sources during the 2013 North American biomass burning episode: analysis of multiple lidar observations in the Western Mediterranean basin

2015 ◽  
Vol 15 (22) ◽  
pp. 32323-32365 ◽  
Author(s):  
G. Ancellet ◽  
J. Pelon ◽  
J. Totems ◽  
P. Chazette ◽  
A. Bazureau ◽  
...  
Keyword(s):  
Long Range ◽  
Biomass Burning ◽  
North American ◽  
Western Mediterranean ◽  
Saharan Dust ◽  
Trade Wind ◽  
Long Range Transport ◽  
Range Transport ◽  
Aerosol Sources ◽  
Aerosol Source

Abstract. Long range transport of biomass burning (BB) aerosols between North America and the Mediterranean region took place in June 2013. A large number of ground based and airborne lidar measurements were deployed in the Western Mediterranean during the Chemistry-AeRosol Mediterranean EXperiment (ChArMEx) intensive observation period. A detailed analysis of the potential North American aerosol sources is conducted including the assessment of their transport to Europe using forward simulations of the FLEXPART Lagrangian particle dispersion model initialized using satellite observations by MODIS and CALIOP. The three dimensional structure of the aerosol distribution in the ChArMEx domain observed by the ground-based lidars (Menorca, Barcelona and Lampedusa), a Falcon-20 aircraft flight and three CALIOP tracks, agree very well with the model simulation of the three major sources considered in this work: Canadian and Colorado fires, a dust storm from Western US and the contribution of Saharan dust streamers advected from the North Atlantic trade wind region into the Westerlies region. Four aerosol types were identified using the optical properties of the observed aerosol layers (aerosol depolarization ratio, lidar ratio) and the transport model analysis of the contribution of each aerosol source: (I) pure BB layer, (II) weakly dusty BB, (III) significant mixture of BB and dust transported from the trade wind region (IV) the outflow of Saharan dust by the subtropical jet and not mixed with BB aerosol. The contribution of the Canadian fires is the major aerosol source during this episode while mixing of dust and BB is only significant at altitude above 5 km. The mixing corresponds to a 20–30 % dust contribution in the total aerosol backscatter. The comparison with the MODIS AOD horizontal distribution during this episode over the Western Mediterranean sea shows that the Canadian fires contribution were as large as the direct northward dust outflow from Sahara.

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