Field Evaluation of Low-Cost PM Sensors (Purple Air PA-II) Under Variable Urban Air Quality Conditions, in Greece

Atmosphere, Год журнала: 2020, Номер 11(9), С. 926 - 926

Опубликована: Авг. 29, 2020

Recent advances in particle sensor technologies have led to an increased development and utilization of low-cost, compact, particulate matter (PM) monitors. These devices can be deployed dense monitoring networks, enabling improved characterization the spatiotemporal variability ambient levels exposure. However, reliability their measurements is important prerequisite, necessitating rigorous performance evaluation calibration comparison reference-grade instrumentation. In this study, field Purple Air PA-II (low-cost PM sensors) performed two urban environments across three seasons Greece, different types reference instruments. Measurements were conducted Athens (the largest city Greece with nearly four-million inhabitants) for five months spanning over summer 2019 winter/spring 2020 Ioannina, a medium-sized northwestern (100,000 during 2019–2020. The PM2.5 output correlates strongly (R2 = 0.87 against beta attenuation monitor R2 0.98 optical monitor). Deviations sensor-reference agreement are identified as mainly related elevated coarse concentrations high relative humidity. Simple multiple regression models tested compensate these biases, drastically improving sensor’s response. Large decreases error observed after implementation models, leading mean absolute percentage errors 0.18 0.12 Ioannina datasets, respectively. Overall, quality-controlled robustly evaluated low-cost network integral component air quality smart city. Case studies presented along line, where used deterioration peri-urban forest fire event affecting area extreme wintertime smog events wood burning residential heating.

Язык: Английский

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Apportionment of black and brown carbon spectral absorption sources in the urban environment of Athens, Greece, during winter

The Science of The Total Environment, Год журнала: 2021, Номер 801, С. 149739 - 149739

Опубликована: Авг. 20, 2021

Язык: Английский

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Brown carbon light absorption over an urban environment in northern peninsular Southeast Asia

Environmental Pollution, Год журнала: 2021, Номер 276, С. 116735 - 116735

Опубликована: Фев. 11, 2021

Язык: Английский

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Review of Brown Carbon Aerosols in China: Pollution Level, Optical Properties, and Emissions

Journal of Geophysical Research Atmospheres, Год журнала: 2022, Номер 127(16)

Опубликована: Авг. 9, 2022

Abstract Brown carbon (BrC) has been recognized as an important contributor to global warming due its absorption of solar radiation with strong wavelength dependence. While early studies mostly consider biomass burning a major emission source, few recent have suggested coal combustion and vehicle exhaust contributors BrC emissions. Considering dominant consumption, large residential biofuel usage, the increasing number vehicles, pollution could result in remarkable regional climate effects China. This study gives overview sources, chemical composition properties BrC, focusing on categorization measurement techniques. The basic features China, including surface concentrations, column burden, sources associated absorbing are then summarized compared other countries. emissions well optical at 365 nm from primary China also provide more straightforward understanding light‐absorbing With detailed comparison existing publications, deeper insight into uncertainties measurements will improve effect BrC. review recommends key research areas for further investigation future.

Язык: Английский

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The Roles of N, S, and O in Molecular Absorption Features of Brown Carbon in PM_2.5 in a Typical Semi‐Arid Megacity in Northwestern China

Journal of Geophysical Research Atmospheres, Год журнала: 2021, Номер 126(16)

Опубликована: Авг. 9, 2021

Abstract Brown Carbon (BrC) absorbs light in wavelength of 300–400 nm, and BrC molecule (BrCM) is a fundamental component responsible for aerosol radiative forcing. In this study, Fourier‐transform ion cyclotron resonance mass spectrometry (FT‐ICR MS) coupled with electrospray ionization (ESI) was used to determine methanol extracted BrCM PM 2.5 collected Xi'an, China. The absorption individual quantified through partial least square regression (PLSR) method. Results showed that 77.5% 91.8% winter summer BrCMs were weak absorptive. top 60.4% 84.6%, respectively, the absorbances winter. nitrogen (N)‐containing organic molecules identified be critical components light‐absorbing matters both two seasons, outlining significance N chromogenesis BrC. more closely related ‐(O)NO 2 originated from NO engaged reactions winter, ‐NH formed NH 3 summer. Sulfur (S)‐containing functional groups not chromophoric while sulfur dioxide (SO ) triggered N‐containing S‐free formations under high oxides (NOx) concentration levels relative humidity (RH) Hypochromicity oxygen (O) discovered because photobleaching oxidation highly oxidized molecules.

Язык: Английский

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Impacts of severe residential wood burning on atmospheric processing, water-soluble organic aerosol and light absorption, in an inland city of Southeastern Europe

Atmospheric Environment, Год журнала: 2022, Номер 280, С. 119139 - 119139

Опубликована: Май 2, 2022

Язык: Английский

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Classification of aerosols over Saudi Arabia from 2004–2016

Atmospheric Environment, Год журнала: 2020, Номер 241, С. 117785 - 117785

Опубликована: Июль 17, 2020

Язык: Английский

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Carbonaceous Aerosols in Contrasting Atmospheric Environments in Greek Cities: Evaluation of the EC-tracer Methods for Secondary Organic Carbon Estimation

Atmosphere, Год журнала: 2020, Номер 11(2), С. 161 - 161

Опубликована: Фев. 4, 2020

This study examines the carbonaceous-aerosol characteristics at three contrasting urban environments in Greece (Ioannina, Athens, and Heraklion), on basis of 12 h sampling during winter (January to February 2013), aiming explore inter-site differences atmospheric composition sources. The winter-average organic carbon (OC) elemental (EC) concentrations Ioannina were found be 28.50 4.33 µg m−3, respectively, much higher than those Heraklion (3.86 m−3 for OC 2.29 EC) Athens (7.63 2.44 EC). OC/EC ratio (6.53) was almost times that (2.03), indicating a larger impact wood combustion, especially night, whereas Heraklion, emissions from biomass burning less intense. Estimations primary secondary (POC SOC) using EC-tracer method, specifically its minimum R-squared (MRS) variant, revealed large between sites, with prevalence POC (67–80%) SOC fraction (53%) Heraklion. estimates also obtained 5% 25% percentiles data determine (OC/EC)pri, leading results MRS approach (70–74% SOC). Although method provides generally more robust results, it may significantly underestimate levels highly burdened by burning, as fast-oxidized semi-volatile associated combustion sources is classified POC. Further analysis difference percentile methods coincided oxygenated aerosol quantified mass spectrometry. Finally, OC/Kbb+ used tracer decomposition into fossil-fuel biomass-burning components, POC, (77%).

Язык: Английский

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Amplification of black carbon light absorption induced by atmospheric aging: temporal variation at seasonal and diel scales in urban Guangzhou

Atmospheric chemistry and physics, Год журнала: 2020, Номер 20(4), С. 2445 - 2470

Опубликована: Фев. 28, 2020

Abstract. Black carbon (BC) aerosols have been widely recognized as a vital climate forcer in the atmosphere. Amplification of light absorption can occur due to coatings on BC during atmospheric aging, an effect that remains uncertain accessing radiative forcing BC. Existing studies enhancement factor (Eabs) poor coverage both seasonal and diurnal scales. In this study, we applied recently developed minimum R squared (MRS) method, which cover scales, for Eabs quantification. Using field measurement data Guangzhou, aims study are explore (1) temporal dynamics optical properties at (wet season, 31 July–10 September; dry 15 November 2017–15 January 2018) diel scales (1 h time resolution) typical urban environment (2) influencing factors variability. Mass efficiency 520 nm by primary (MAEp520) determined MRS method exhibited strong seasonality (8.6 m2 g−1 wet season 16.8 season). Eabs520 was higher (1.51±0.50) lower (1.29±0.28). Absorption Ångström exponent (AAE470–660) (1.46±0.12) than (1.37±0.10). Collective evidence showed active biomass burning (BB) effectively altered BC, leading elevated MAE, MAEp AAE compared those season. Diurnal positively correlated with AAE470–660 (R2=0.71) negatively AE33 aerosol loading compensation parameter (k) (R2=0.74) but these correlations were significantly weaker may be related impact BB. This result suggests lensing more likely dominating variability rather contribution from brown (BrC). Secondary processing affect dynamics. The clear dependency ratio secondary organic (SOC∕OC), confirming Eabs; well nitrate dependence temperature. new finding implies gas–particle partitioning semivolatile compounds potentially play important role steering fluctuation Eabs520. associated photochemical aging evidenced good correlation (R2=0.69) between oxidant concentrations (Ox=O3+NO2)

Язык: Английский

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Brown carbon absorption and radiative effects under intense residential wood burning conditions in Southeastern Europe: New insights into the abundance and absorptivity of methanol-soluble organic aerosols

The Science of The Total Environment, Год журнала: 2022, Номер 860, С. 160434 - 160434

Опубликована: Ноя. 24, 2022

Язык: Английский

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