Secondary organic aerosol formation during June 2010 in Central Europe: measurements and modelling studies with a mixed thermodynamic-kinetic approach

Abstract. Until recently secondary organic carbon aerosol (SOA) mass concentrations have been systematically underestimated by three-dimensional atmospheric-chemistry-aerosol models. With a newly proposed concept of aging of organic vapours, more realistic model results for organic carbon aerosol mass concentrations can be achieved. Applying a mixed thermodynamic-kinetic approach for SOA formation shifted the aerosol size distribution towards particles in the cloud condensation nuclei size range, thereby emphasising the importance of SOA formation schemes for modelling realistic cloud and precipitation formation. The additional importance of hetero-molecular nucleation between H2SO4 and organic vapours remains to be evaluated in three-dimensional atmospheric-chemistry-aerosol models. Here a case study is presented focusing on Puy-de-Dôme, France in June 2010. The measurements indicate a considerable increase in SOA mass concentration during the measurement campaign, which could be reproduced by modelling using a simplified thermodynamic-kinetic approach for SOA formation and increased biogenic volatile organic compound (VOC) precursor emissions. Comparison with a thermodynamic SOA formation approach shows a huge improvement in modelled SOA mass concentration with the thermodynamic-kinetic approach for SOA formation. SOA mass concentration increases by a factor of up to 6 accompanied by a slight improvement of modelled particle size distribution. Even though nucleation events at Puy-de-Dôme were rare during the chosen period of investigation, a weak event in the boundary layer could be reproduced by the model in a sensitivity study when nucleation of low-volatile secondary organic vapour is included. Differences in the model results with and without nucleation of organic vapour are visible in the lower free troposphere over several days. Taking into account the nucleation of organic vapour leads to an increase in accumulation mode particles due to coagulation and condensational growth of nucleation and Aitken mode particles.

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Secondary organic aerosol formation during June 2010 in Central Europe: measurements and modelling studies with a mixed thermodynamic-kinetic approach

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-13-26761-2013 ◽

2013 ◽

Vol 13 (10) ◽

pp. 26761-26793

Author(s):

B. Langmann ◽

K. Sellegri ◽

E. Freney

Keyword(s):

Organic Carbon ◽

Size Distribution ◽

Atmospheric Chemistry ◽

Mass Concentration ◽

Three Dimensional ◽

Kinetic Approach ◽

Aerosol Formation ◽

Aerosol Mass ◽

Aerosol Mass Concentration ◽

Organic Vapour

Abstract. Until recently secondary organic carbon (SOC) aerosol mass concentrations have been systematically underestimated by three-dimensional atmospheric-chemistry-aerosol models. With a newly proposed concept of aging of organic vapours more realistic model results for organic carbon aerosol mass concentrations could be achieved. Applying a mixed thermodynamic-kinetic approach for SOC aerosol formation shifted the aerosol size distribution towards particles in the cloud condensation nuclei size range, thereby emphasising the importance of SOC aerosol formation schemes for modelling realistic cloud and precipitation formation. The additional importance of hetero-molecular nucleation between H2SO4 and organic vapours remains to be evaluated in three-dimensional atmospheric-chemistry-aerosol models. Here a case study is presented focusing on Puy-de-Dôme, France in June 2010. Even though nucleation events at Puy-de-Dôme were rare during the chosen period of investigation a weak event in the boundary layer could be reproduced by the model when nucleation of low-volatile secondary organic vapour is included. Differences in the model results with and without nucleation of organic vapour are visible in the lower free troposphere over several days of the period. Taking into account nucleation of organic vapour leads to an increase in accumulation mode particles due to coagulation of nucleation and aitken mode particles. Moreover, the measurements indicate a considerable increase in SOC aerosol mass concentration during the measurement campaign, which could be reproduced by modelling using a simplified thermodynamic-kinetic approach for SOC aerosol formation and increased biogenic VOC precursor emissions. Comparison with a thermodynamic SOC aerosol formation approach shows a huge improvement in modelled SOC aerosol mass concentration with the thermodynamic-kinetic approach for SOC aerosol formation and a slight improvement of modelled particle size distribution.

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Pollution Characteristics of Atmospheric Carbonyls in Urban Linfen in Winter

Atmosphere ◽

10.3390/atmos11070685 ◽

2020 ◽

Vol 11 (7) ◽

pp. 685

Author(s):

Fanxiu Li ◽

Hengyuan Wang ◽

Xuezhong Wang ◽

Zhigang Xue ◽

Liqin Duan ◽

...

Keyword(s):

Urban Area ◽

Atmospheric Chemistry ◽

Mass Concentration ◽

High Performance ◽

Exhaust Emissions ◽

Photochemical Reactions ◽

Vehicle Exhaust ◽

Pollution Characteristics ◽

The North ◽

Mass Concentrations

Atmospheric carbonyls (aldehyde and ketone compounds) can be precursors for ozone and PM2.5, and they play an essential role in atmospheric chemistry. Linfen is a basin between mountains on the east and west, and there are many coking plants on the north and south sides of its urban area. The special topography and unfortunate industrial layout have frequently contributed to serious air pollution in Linfen. In order to investigate the pollution characteristics of atmospheric carbonyls in winter in urban Linfen, the carbonyl compounds were collected from the Municipal Committee site (MC) and the Yaowangtai site (YWT) from 16 to 25 January 2019, and their concentrations were analyzed by a high performance liquid chromatography-ultraviolet detector (HPLC-UV). The results show that formaldehyde, acetaldehyde, and acetone were the most abundant compounds, accounting for more than 70% of the total mass concentration of carbonyls in urban Linfen. Levels of these three carbonyls increased during the morning and evening traffic rush hours. The mass concentration of formaldehyde at both sites reached peak values at around noon (10:00–14:00). In addition, the mass concentrations of formaldehyde, acetaldehyde, and acetone were positively correlated with CO mass concentrations, whereas only formaldehyde and acetaldehyde were positively correlated with temperature. Therefore, atmospheric formaldehyde in urban Linfen’s winter mainly came from vehicle exhaust emissions and the secondary generation of photochemical reactions. Most of the acetaldehyde came from vehicle exhaust emissions, and photochemical reactions also partially contributed to it. For acetone, vehicle exhaust emissions were the main source. In addition, coking industry emissions from Northern Linfen′s Hongtong County may also have contributed to the atmospheric carbonyls in the urban area of Linfen. For the first time, this study found that formaldehyde showed different behavior to acetaldehyde and acetone; that is, the nighttime decrease in formaldehyde mass concentration was greater than that of acetaldehyde and acetone.

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Neural network modelling to estimate particle size distribution based on other particle sections and meteorological parameters

10.5194/amt-2021-37 ◽

2021 ◽

Author(s):

Pak Lun Fung ◽

Martha Arbayani Zaidan ◽

Ola Surakhi ◽

Sasu Tarkoma ◽

Tuukka Petäjä ◽

...

Keyword(s):

Neural Network ◽

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Meteorological Parameters ◽

Aerosol Size Distribution ◽

Sufficient Information ◽

Electrical Mobility ◽

Particle Sizer ◽

Mass Concentrations

Abstract. In air quality research, often only particle mass concentrations as indicators of aerosol particles are considered. However, the mass concentrations do not provide sufficient information to convey the full story of fractionated size distribution, which are able to deposit differently on respiratory system and cause various harm. Aerosol size distribution measurements rely on a variety of techniques to classify the aerosol size and measure the size distribution. From the raw data the ambient size distribution is determined utilising a suite of inversion algorithms. However, the inversion problem is quite often ill-posed and challenging to invert. Due to the instrumental insufficiency and inversion limitations, models for fractionated particle size distribution are of great significance to fill the missing gaps or negative values. The study at hand involves a merged particle size distribution, from a scanning mobility particle sizer (NanoSMPS) and an optical particle sizer (OPS) covering the aerosol size distributions from 0.01 to 0.42 μm (electrical mobility equivalent size) and 0.3 μm to 10 μm (optical equivalent size) and meteorological parameters collected at an urban background region in Amman, Jordan in the period of 1st Aug 2016–31st July 2017. We develop and evaluate feed-forward neural network (FFNN) models to estimate number concentrations at particular size bin with (1) meteorological parameters, (2) number concentration at other size bins, and (3) both of the above as input variables. Two layers with 10–15 neurons are found to be the optimal option. Lower model performance is observed at the lower edge (0.01

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Mass or total surface area with aerosol size distribution as exposure metrics for inflammatory, cytotoxic and oxidative lung responses in rats exposed to titanium dioxide nanoparticles

Toxicology and Industrial Health ◽

10.1177/0748233716651560 ◽

2016 ◽

Vol 33 (4) ◽

pp. 351-364 ◽

Cited By ~ 10

Author(s):

A Noël ◽

G Truchon ◽

Y Cloutier ◽

M Charbonneau ◽

K Maghni ◽

...

Keyword(s):

Oxidative Stress ◽

Size Distribution ◽

Surface Area ◽

Stress Responses ◽

Mass Concentration ◽

Total Surface Area ◽

Aerosol Size Distribution ◽

Exposure Metrics ◽

Oxidative Stress Responses ◽

And Oxidative Stress

There is currently no consensus on the best exposure metric(s) for expressing nanoparticle (NP) dose. Although surface area has been extensively studied for inflammatory responses, it has not been as thoroughly validated for cytotoxicity or oxidative stress effects. Since inhaled NPs deposit and interact with lung cells based on agglomerate size, we hypothesize that mass concentration combined with aerosol size distribution is suitable for NP risk assessment. The objective of this study was to evaluate different exposure metrics for inhaled 5 nm titanium dioxide aerosols composed of small (SA < 100 nm) or large (LA > 100 nm) agglomerates at 2, 7, and 20 mg/m3 on rat lung inflammatory, cytotoxicity, and oxidative stress responses. We found a significant positive correlation ( r = 0.98, p < 0.01) with the inflammatory reaction, measured by the number of neutrophils and the mass concentration when considering all six (SA + LA) aerosols. This correlation was similar ( r = 0.87) for total surface area. Regarding cytotoxicity and oxidative stress responses, measured by lactate dehydrogenase and 8-isoprostane, respectively, and mass or total surface area as an exposure metric, we observed significant positive correlations only with SA aerosols for both the mass concentration and size distribution ( r > 0.91, p < 0.01), as well as for the total surface area ( r > 0.97, p < 0.01). These data show that mass or total surface area concentrations alone are insufficient to adequately predict oxidant and cytotoxic pulmonary effects. Overall, our study indicates that considering NP size distribution along with mass or total surface area concentrations contributes to a more mechanistic discrimination of pulmonary responses to NP exposure.

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Technical Note: A new SIze REsolved Aerosol Model (SIREAM)

Atmospheric Chemistry and Physics ◽

10.5194/acp-7-1537-2007 ◽

2007 ◽

Vol 7 (6) ◽

pp. 1537-1547 ◽

Cited By ~ 79

Author(s):

E. Debry ◽

K. Fahey ◽

K. Sartelet ◽

B. Sportisse ◽

M. Tombette

Keyword(s):

Size Distribution ◽

Transport Model ◽

Three Dimensional ◽

Technical Note ◽

Aerosol Size Distribution ◽

Short Paper ◽

Chemistry Transport Model ◽

Dynamical Mass ◽

Aerosol Model ◽

Transfer Method

Abstract. We briefly present in this short paper a new SIze REsolved Aerosol Model (SIREAM) which simulates the evolution of atmospheric aerosol by solving the General Dynamic Equation (GDE). SIREAM segregates the aerosol size distribution into sections and solves the GDE by splitting coagulation and condensation/evaporation-nucleation. A quasi-stationary sectional approach is used to describe the size distribution change due to condensation/evaporation, and a hybrid equilibrium/dynamical mass-transfer method has been developed to lower the computational burden. SIREAM uses the same physical parameterizations as those used in the Modal Aerosol Model, MAM Sartelet et al. (2006). It is hosted in the modeling system Polyphemus Mallet et al., 2007, but can be linked to any other three-dimensional Chemistry-Transport Model.

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Presenting SAPUSS: Solving Aerosol Problem by Using Synergistic Strategies in Barcelona, Spain

Atmospheric Chemistry and Physics ◽

10.5194/acp-13-8991-2013 ◽

2013 ◽

Vol 13 (17) ◽

pp. 8991-9019 ◽

Cited By ~ 20

Author(s):

M. Dall'Osto ◽

X. Querol ◽

A. Alastuey ◽

M. C. Minguillon ◽

M. Alier ◽

...

Keyword(s):

Atmospheric Chemistry ◽

Complex Dynamics ◽

Road Traffic ◽

Three Dimensional ◽

Ground Level ◽

Western Mediterranean ◽

Night Time ◽

Ozone Concentrations ◽

Western Mediterranean Basin ◽

Mass Concentrations

Abstract. This paper presents the summary of the key objectives, instrumentation and logistic details, goals, and initial scientific findings of the European Marie Curie Action SAPUSS project carried out in the western Mediterranean Basin (WMB) during September–October in autumn 2010. The key SAPUSS objective is to deduce aerosol source characteristics and to understand the atmospheric processes responsible for their generations and transformations – both horizontally and vertically in the Mediterranean urban environment. In order to achieve so, the unique approach of SAPUSS is the concurrent measurements of aerosols with multiple techniques occurring simultaneously in six monitoring sites around the city of Barcelona (NE Spain): a main road traffic site, two urban background sites, a regional background site and two urban tower sites (150 m and 545 m above sea level, 150 m and 80 m above ground, respectively). SAPUSS allows us to advance our knowledge sensibly of the atmospheric chemistry and physics of the urban Mediterranean environment. This is well achieved only because of both the three dimensional spatial scale and the high sampling time resolution used. During SAPUSS different meteorological regimes were encountered, including warm Saharan, cold Atlantic, wet European and stagnant regional ones. The different meteorology of such regimes is herein described. Additionally, we report the trends of the parameters regulated by air quality purposes (both gaseous and aerosol mass concentrations); and we also compare the six monitoring sites. High levels of traffic-related gaseous pollutants were measured at the urban ground level monitoring sites, whereas layers of tropospheric ozone were recorded at tower levels. Particularly, tower level night-time average ozone concentrations (80 ± 25 μg m−3) were up to double compared to ground level ones. The examination of the vertical profiles clearly shows the predominant influence of NOx on ozone concentrations, and a source of ozone aloft. Analysis of the particulate matter (PM) mass concentrations shows an enhancement of coarse particles (PM2.5–10) at the urban ground level (+64%, average 11.7 μg m−3) but of fine ones (PM1) at urban tower level (+28%, average 14.4 μg m−3). These results show complex dynamics of the size-resolved PM mass at both horizontal and vertical levels of the study area. Preliminary modelling findings reveal an underestimation of the fine accumulation aerosols. In summary, this paper lays the foundation of SAPUSS, an integrated study of relevance to many other similar urban Mediterranean coastal environment sites.

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Evaluation of the sectional aerosol microphysics module SALSA implementation in ECHAM5-HAM aerosol-climate model

Geoscientific Model Development ◽

10.5194/gmd-5-845-2012 ◽

2012 ◽

Vol 5 (3) ◽

pp. 845-868 ◽

Cited By ~ 42

Author(s):

T. Bergman ◽

V.-M. Kerminen ◽

H. Korhonen ◽

K. J. Lehtinen ◽

R. Makkonen ◽

...

Keyword(s):

Organic Carbon ◽

Size Distribution ◽

Black Carbon ◽

Climate Model ◽

Good Choice ◽

Sea Salt ◽

Aerosol Size Distribution ◽

Chemical Compositions ◽

Model Framework ◽

Aerosol Properties

Abstract. We present the implementation and evaluation of a sectional aerosol microphysics module SALSA within the aerosol-climate model ECHAM5-HAM. This aerosol microphysics module has been designed to be flexible and computationally efficient so that it can be implemented in regional or global scale models. The computational efficiency has been achieved by minimising the number of variables needed to describe the size and composition distribution. The aerosol size distribution is described using 10 size classes with parallel sections which can have different chemical compositions. Thus in total, the module tracks 20 size sections which cover diameters ranging from 3 nm to 10 μm and are divided into three subranges, each with an optimised selection of processes and compounds. The implementation of SALSA into ECHAM5-HAM includes the main aerosol processes in the atmosphere: emissions, removal, radiative effects, liquid and gas phase sulphate chemistry, and the aerosol microphysics. The aerosol compounds treated in the module are sulphate, organic carbon, sea salt, black carbon, and mineral dust. In its default configuration, ECHAM5-HAM treats aerosol size distribution using the modal method. In this implementation, the aerosol processes were converted to be used in a sectional model framework. The ability of the module to describe the global aerosol properties was evaluated by comparing against (1) measured continental and marine size distributions, (2) observed variability of continental number concentrations, (3) measured sulphate, organic carbon, black carbon and sea-salt mass concentrations, (4) observations of aerosol optical depth (AOD) and other aerosol optical properties from satellites and AERONET network, (5) global aerosol budgets and concentrations from previous model studies, and (6) model results using M7, which is the default aerosol microphysics module in ECHAM5-HAM. The evaluation shows that the global aerosol properties can be reproduced reasonably well using a coarse resolution of 10 sections in size space. The simulated global aerosol budgets are within the range of previous studies. Surface concentrations of sulphate and carbonaceous species have an annual mean within a factor of two of the observations. The simulated sea-salt concentrations reproduce the observations within a factor of two, apart from the Southern Ocean over which the concentrations are within a factor of five. Regionally, AOD is in a relatively good agreement with the observations (within a factor of two). At mid-latitudes the observed AOD is captured well, while at high-latitudes as well as in some polluted and dust regions the modelled AOD is significantly lower than observed. Regarding most of the investigated aerosol properties, the SALSA and the modal aerosol module M7 perform comparably well against observations. However, SALSA reproduces the observed number concentrations and the size distribution of CCN sized particles much more accurately than M7, and is therefore a good choice for aerosol-cloud interaction studies in global models. Our study also shows that when activation type nucleation in the boundary layer is included, the observed concentration of particles under 50 nm in diameter are reproduced much better compared to when only binary nucleation in the free troposphere is assumed.

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Consistent simulation of bromine chemistry from the marine boundary layer to the stratosphere – Part 1: Model description, sea salt aerosols and pH

Atmospheric Chemistry and Physics ◽

10.5194/acp-8-5899-2008 ◽

2008 ◽

Vol 8 (19) ◽

pp. 5899-5917 ◽

Cited By ~ 24

Author(s):

A. Kerkweg ◽

P. Jöckel ◽

A. Pozzer ◽

H. Tost ◽

R. Sander ◽

...

Keyword(s):

Size Distribution ◽

Atmospheric Chemistry ◽

General Circulation ◽

Circulation Model ◽

Reaction Rates ◽

Sea Salt ◽

Aerosol Size Distribution ◽

Model Description ◽

Aerosol Chemistry ◽

Coarse Mode

Abstract. This is the first article of a series presenting a detailed analysis of bromine chemistry simulated with the atmospheric chemistry general circulation model ECHAM5/MESSy. Release from sea salt is an important bromine source, hence the model explicitly calculates aerosol chemistry and phase partitioning for coarse mode aerosol particles. Many processes including chemical reaction rates are influenced by the particle size distribution, and aerosol associated water strongly affects the aerosol pH. Knowledge of the aerosol pH is important as it determines the aerosol chemistry, e.g., the efficiency of sulphur oxidation and bromine release. Here, we focus on the simulated sea salt aerosol size distribution and the coarse mode aerosol pH. A comparison with available field data shows that the simulated aerosol distributions agree reasonably well within the range of measurements. In spite of the small number of aerosol pH measurements and the uncertainty in its experimental determination, the simulated aerosol pH compares well with the observations. The aerosol pH ranges from alkaline aerosol in areas of strong production down to pH-values of 1 over regions of medium sea salt production and high levels of gas phase acids, mostly polluted regions over the oceans in the Northern Hemisphere.

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Technical Note: A new SIze REsolved Aerosol Model (SIREAM)

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-6-11845-2006 ◽

2006 ◽

Vol 6 (6) ◽

pp. 11845-11875 ◽

Cited By ~ 2

Author(s):

E. Debry ◽

K. Fahey ◽

K. Sartelet ◽

B. Sportisse ◽

M. Tombette

Keyword(s):

Size Distribution ◽

Atmospheric Aerosol ◽

Transport Model ◽

Three Dimensional ◽

Technical Note ◽

Aerosol Size Distribution ◽

Short Paper ◽

Chemistry Transport Model ◽

Aerosol Model ◽

General Dynamic

Abstract. We briefly present in this short paper a new SIze REsolved Aerosol Model (SIREAM) which simulates the evolution of atmospheric aerosol by solving the General Dynamic Equation (GDE). SIREAM segregates the aerosol size distribution into sections and solves the GDE by splitting coagulation and condensation/evaporation. A moving sectional approach is used to describe the size distribution change due to condensation/evaporation and a hybrid method has been developed to lower the computational burden. SIREAM uses the same physical parameterizations as those used in the Modal Aerosol Model, MAM sartelet05development. It is hosted in the modeling system POLYPHEMUS (Mallet et al., 2006) but can be linked to any other three-dimensional Chemistry-Transport Model.

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Optical and chemical properties of wintertime light-absorbing aerosols in the eastern Indo-Gangetic Plain, India

10.5194/egusphere-egu2020-655 ◽

2020 ◽

Author(s):

Supriya Dey ◽

Archita Rana ◽

Prashant Rawat ◽

Sayantan Sarkar

Keyword(s):

Organic Carbon ◽

Light Absorption ◽

Mass Concentration ◽

Chemical Properties ◽

Water Soluble ◽

Chemical Extraction ◽

Aerosol Formation ◽

Gangetic Plain ◽

Indo Gangetic Plain ◽

And Chemical Properties

Light-absorbing carbonaceous aerosols such as black and brown carbon (BC and BrC) and humic-like substances (HULIS) have pronounced effects on the earth&#8217;s radiative balance and tropospheric photochemistry. In India, large heterogeneities exist for BC and organic carbon (OC) emission inventories, which necessitates regionally-representative ground-based measurements. Such measurements are spatially scattered for BC, rare for BrC and non-existent for HULIS. This severely limits a robust understanding of the optical and chemical properties of these aerosols, and consequently, their climate effects. To address this issue, the present study reports optical and chemical properties of wintertime (December 2018-February 2019) BC, BrC and HULIS at a rural receptor site in the highly polluted eastern Indo-Gangetic Plain (IGP), India. A 7 wavelength aethalometer was deployed to measure time-resolved BC mass concentration, and absorption coefficients (babs) and Angstrom exponent (AE) of BrC. Separation of aqueous and organic BrC (BrCaq and BrCorg) and HULIS fractions via a multi-step chemical extraction procedure followed by optical measurements (UV-Vis, fluorescence and FT-IR), and supplementary measurements of OC, water-soluble organic carbon (WSOC) and ionic species led to better insights into the potential chromophore composition and their relative importance in constraining aerosol optical properties.The daily averaged BC mass concentration was 15.4&#177;9.5 &#956;g m-3 during winter, where the biomass burning (BB) contribution was 25&#177;5%. The diurnal profile of BCBB and BrC light absorption coefficient (babs_BrC) showed a prominent morning peak (0700-0800 H) characterized by mixed fossil fuel and biofuel emission and a gradual increase towards night due to enhanced primary BB emission from cooking activities and lowering of the mixing depth. The regionally transported BB plume from northwestern IGP contributed substantial BC and BrC to this receptor location in the eastern end of the corridor, which was supported by concentration-weighted air mass trajectories (CWTs).The BrCorg light absorption at 365 nm (babs_BrC_org) was almost 2 times compared to that of BrCaq (babs_BrC_aq) (36&#177;7.1 vs 18.3&#177;4.3 Mm-1), which suggested a dominance of non-polar polyconjugated BrC chromophores. This was also supported by the increasing trend of water-insoluble BrC from 49&#177;10% at 365 nm to 64&#177;21% at 550 nm, with averaged contributions of 49&#177;8% at 300-400 nm and 67&#177;9% at 400-550 nm, respectively. A strong correlation between WSOC and NO3- (r=0.78, p<0.01) and WSOC and NH4+ (r=0.63, p<0.01) indicated the possibility of nighttime secondary organic aerosol formation. A prominent fluorescence peak at ~409 nm for BrCaq confirmed the presence of HULIS, and babs_BrC_aq was dominated by the low-polarity HULIS-n fraction. AE of individual HULIS fractions increased by 7-36% towards the more polar HULIS-a and highly-polar water-soluble organic matter (HPWSOM) compared to the less polar HULIS-n for the 300-700 nm range. Distinct FTIR peaks at 3400 cm-1, 1710 cm-1 and 1643 cm-1 suggested abundance of C-H, C=O and C=C functional groups, respectively, in the BrC chromophores. Overall, it appeared that the regionally transported BB plume significantly enriches BrC and HULIS in the eastern part of the IGP corridor. &#160;&#160;

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