scholarly journals In-depth characterization of submicron particulate matter inter-annual variations at a street canyon site in Northern Europe

2020 ◽  
Author(s):  
Luis M. F. Barreira ◽  
Aku Helin ◽  
Minna Aurela ◽  
Kimmo Teinilä ◽  
Milla Friman ◽  
...  
Keyword(s):  
Air Pollution ◽  
Particulate Matter ◽  
Atmospheric Aerosols ◽  
Street Canyon ◽  
Northern Europe ◽  
Time Resolved ◽  
Annual Variations ◽  
Day Of The Week ◽  
Pollution Episodes

Abstract. Atmospheric aerosols play an important role in air pollution. Aerosol particle's chemical composition is highly variable depending on the season, hour of the day, day of the week, meteorology, and the location of the measurement site. Long measurement periods and high time-resolved data are required in order to achieve statistically relevant amount of data for assessing those variations and evaluate pollution episodes. In this study, we present continuous atmospheric PM1 (particulate matter

scholarly journals In-depth characterization of submicron particulate matter inter-annual variations at a street canyon site in northern Europe

2021 ◽  
Vol 21 (8) ◽  
pp. 6297-6314
Author(s):  
Luis M. F. Barreira ◽  
Aku Helin ◽  
Minna Aurela ◽  
Kimmo Teinilä ◽  
Milla Friman ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Aerosol Particle ◽  
Street Canyon ◽  
Particle Number ◽  
Large Fraction ◽  
Northern Europe ◽  
Time Resolved ◽  
Inorganic Species ◽  
Pollution Episodes

Abstract. Atmospheric aerosols play an important role in air pollution. Aerosol particle chemical composition is highly variable depending on the season, hour of the day, day of the week, meteorology, and location of the measurement site. Long measurement periods and highly time-resolved data are required in order to achieve a statistically relevant amount of data for assessing those variations and evaluating pollution episodes. In this study, we present continuous atmospheric PM1 (particulate matter < 1 µm) concentration and composition measurements at an urban street canyon site located in Helsinki, Finland. The study was performed for 4.5 years (2015–2019) and involved highly time-resolved measurements by taking advantage of a suite of online state-of-the-art instruments such as an aerosol chemical speciation monitor (ACSM), a multi-angle absorption photometer (MAAP), a differential mobility particle sizer (DMPS), and an Aethalometer (AE). PM1 consisted mostly of organics, with mean mass concentrations of 2.89 µg m−3 (53 % of PM1) followed by inorganic species (1.56 µg m−3, 29 %) and equivalent black carbon (eBC, 0.97 µg m−3, 18 %). A trend analysis revealed a decrease in BC from fossil fuel (BCFF), organics, and nitrate over the studied years. Clear seasonal and/or diurnal variations were found for the measured atmospheric PM1 constituents. Particle number and mass size distributions over different seasons revealed the possible influence of secondary organic aerosols (SOAs) during summer and the dominance of ultrafine traffic aerosols during winter. The seasonality of measured constituents also impacted the particle's coating and absorptive properties. The investigation of pollution episodes observed at the site showed that a large fraction of aerosol particle mass was comprised of inorganic species during long-range transport, while during local episodes eBC and organics prevailed together with elevated particle number concentration. Overall, the results increased knowledge of the variability of PM1 concentration and composition in a Nordic traffic site and its implications on urban air quality. Considering the effects of PM mitigation policies in northern Europe in the last decades, the results obtained in this study may be considered illustrative of probable future air quality challenges in countries currently adopting similar environmental regulations.

scholarly journals Assessment of inter-city transport of particulate matter in the Beijing–Tianjin–Hebei region

2018 ◽  
Vol 18 (7) ◽  
pp. 4843-4858 ◽  
Author(s):  
Xing Chang ◽  
Shuxiao Wang ◽  
Bin Zhao ◽  
Siyi Cai ◽  
Jiming Hao
Keyword(s):  
Air Pollution ◽  
Particulate Matter ◽  
Surface Wind ◽  
Air Pollution Control ◽  
Regional Transport ◽  
Transport Pathways ◽  
Monthly Average ◽  
Heavy Pollution ◽  
Pollution Episodes ◽  
Bth Region

Abstract. The regional transport of particulate matter with diameter less than 2.5 µm (PM2.5) plays an important role in the air pollution of the Beijing–Tianjin–Hebei (BTH) region in China. However, previous studies on regional transport of PM2.5 mainly aim at province level, which is insufficient for the development of an optimal joint PM2.5 control strategy. In this study, we calculate PM2.5 inflows and outflows through the administrative boundaries of three major cities in the BTH region, i.e., Beijing, Tianjin and Shijiazhuang, using the WRF (Weather Research and Forecasting model)-CMAQ (Community Multiscale Air Quality) modeling system. The monthly average inflow fluxes indicate the major directions of PM2.5 transport. For Beijing, the PM2.5 inflow fluxes from Zhangjiakou (in the northwest) and Baoding (in the southwest) constitute 57 % of the total in winter, and Langfang (in the southeast) and Baoding constitute 73 % in summer. Based on the net PM2.5 fluxes and their vertical distributions, we find there are three major transport pathways in the BTH region: the northwest–southeast pathway in winter (at all levels below 1000 m), the northwest–southeast pathway in summer (at all levels below 1000 m), and the southwest–northeast pathway in both winter and in summer (mainly at 300–1000 m). In winter, even if surface wind speeds are low, the transport at above 300 m can still be strong. Among the three pathways, the southwest–northeast happens along with PM2.5 concentrations 30 and 55 % higher than the monthly average in winter and summer, respectively. Analysis of two heavy pollution episodes in January and July in Beijing show a much (8–16 times) stronger transport than the monthly average, emphasizing the joint air pollution control of the cities located on the transport pathways, especially during heavy pollution episodes.

Meteorological Factors Affecting Particulate Air Pollution of a City

1961 ◽  
Vol 42 (8) ◽  
pp. 556-560 ◽  
Author(s):  
R. R. Dickson
Keyword(s):  
Air Pollution ◽  
Particulate Matter ◽  
Meteorological Factors ◽  
Absolute Error ◽  
Graphical Analysis ◽  
Factors Affecting ◽  
Particulate Air Pollution ◽  
Day Of The Week ◽  
Matter Concentration ◽  
Pollution Concentrations

Due to its utility in handling joint functions, the method of coaxial graphical correlation is used to relate particulate air pollution at Nashville, Tennessee to various meteorological factors. The derived relationship applied to test data yielded an average absolute error of 38.3 micrograms per cubic meter and root-mean-square error of 59.3; these results are clearly superior to a climatological control forecast using seasonal average concentrations. Graphical analysis and supporting correlation-ratio computations suggest that small amounts of precipitation may be very effective in cleansing particulate matter from the atmosphere, rendering further precipitation of little consequence. The analysis emphasizes the importance of wind direction in governing air-pollution concentrations at a point, suggesting that point measurement of particulate concentrations may have little representativeness when applied to an area the size of a city. Particulate-matter concentration is found significantly correlated with day of the week (weekday-weekend groupings), offering an avenue for improvement of results.

Characterization of the simplest hydroperoxide ester, hydroperoxymethyl formate, a precursor of atmospheric aerosols

2019 ◽  
Vol 21 (33) ◽  
pp. 18065-18070 ◽  
Author(s):  
Jessica P. Porterfield ◽  
Kin Long Kelvin Lee ◽  
Valentina Dell'Isola ◽  
P. Brandon Carroll ◽  
Michael C. McCarthy
Keyword(s):  
Particulate Matter ◽  
Atmospheric Aerosols ◽  
Radiation Budget ◽  
Large Clusters ◽  
Earth’S Radiation Budget

Atmospheric aerosols are large clusters of molecules and particulate matter that profoundly affect the Earth's radiation budget and climate.

scholarly journals Heavy air pollution episodes in Beijing during January 2013: inorganic ion chemistry and source analysis using Highly Time-Resolved Measurements in an urban site

2015 ◽  
Vol 15 (7) ◽  
pp. 11111-11141 ◽  
Author(s):  
B. Han ◽  
R. Zhang ◽  
W. Yang ◽  
Z. Bai ◽  
Z. Ma ◽  
...  
Keyword(s):  
Air Pollution ◽  
Coal Combustion ◽  
Source Analysis ◽  
Urban Site ◽  
Ion Chemistry ◽  
Time Resolved ◽  
Potential Sources ◽  
Air Pollution Episodes ◽  
Pollution Episodes ◽  
Time Resolved Measurements

Abstract. Heavy air pollution episodes occurred in Beijing in January 2013 attracted intensively attention around the whole world. During this period, the authors conducted highly time-resolved measurements of water soluble ions associated with PM2.5 at an urban site, and attempted to distinguish the ion chemistry and potential sources. In this study, hourly mean concentrations of Cl−, NO3−, SO42−, Na+, NH4+, K+, Mg2+ and Ca2+ were measured during the air pollution episode in January 2013, and the ions were found to exist mainly in the form of (NH4)2SO4, NH4NO3, NaCl and KCl in aerosol particles by correlation and linear analysis. SO42− and NO3− were observed peak concentrations in 10–15, 18–20, 21–24, and 26–30 January during this monitoring campaign. The percentage of SO42− and NH4+ in total ions concentrations exhibited an increasing trend with the enhancement of PM2.5 concentration, indicating high concentrations of SO42− and NH4+ had played important roles in the formation of air pollution episodes. Ratio of [NO3−]/[SO42−] was calculated, finding the sources of SO42− would contribute more to the formation of PM2.5 than mobile sources. Diurnal variations of SO42−, NO3−, NH4+ were examined, and all of them exhibited similar pattern with high concentration in night and relative low level at daytime. Emission from coal combustion, remote transportation at night or impact of meteorological was likely to be responsible for the high level of SO42−, NH4+ andNO3−. Potential sources were identified by applying PMF. Secondary nitrate, secondary sulfate, coal combustion and biomass burning, as well as fugitive dust were considered as the major contributors to total ions.

scholarly journals Predicted ultrafine particulate matter source contribution across the continental United States during summertime air pollution events

2019 ◽  
Vol 19 (14) ◽  
pp. 9399-9412 ◽  
Author(s):  
Melissa A. Venecek ◽  
Xin Yu ◽  
Michael J. Kleeman
Keyword(s):  
United States ◽  
Air Pollution ◽  
Particulate Matter ◽  
Los Angeles ◽  
San Francisco ◽  
The United States ◽  
Biomass Combustion ◽  
Spatial Gradients ◽  
Ultrafine Particulate Matter ◽  
Pollution Episodes

Abstract. The regional concentrations of airborne ultrafine particulate matter mass (Dp<0.1 µm; PM0.1) were predicted in 39 cities across the United States (US) during summertime air pollution episodes. Calculations were performed using a regional source-oriented chemical transport model with 4 km spatial resolution operating on the National Emissions Inventory created by the U.S. Environmental Protection Agency (EPA). Measured source profiles for particle size and composition between 0.01 and 10 µm were used to translate PM total mass to PM0.1. Predicted PM0.1 concentrations exceeded 2 µg m−3 during summer pollution episodes in major urban regions across the US including Los Angeles, the San Francisco Bay Area, Houston, Miami, and New York. PM0.1 spatial gradients were sharper than PM2.5 spatial gradients due to the dominance of primary aerosol in PM0.1. Artificial source tags were used to track contributions to primary PM0.1 and PM2.5 from 15 source categories. On-road gasoline and diesel vehicles made significant contributions to regional PM0.1 in all 39 cities even though peak contributions within 0.3 km of the roadway were not resolved by the 4 km grid cells. Cooking also made significant contributions to PM0.1 in all cities but biomass combustion was only important in locations impacted by summer wildfires. Aviation was a significant source of PM0.1 in cities that had airports within their urban footprints. Industrial sources, including cement manufacturing, process heating, steel foundries, and paper and pulp processing, impacted their immediate vicinity but did not significantly contribute to PM0.1 concentrations in any of the target 39 cities. Natural gas combustion made significant contributions to PM0.1 concentrations due to the widespread use of this fuel for electricity generation, industrial applications, residential use, and commercial use. The major sources of primary PM0.1 and PM2.5 were notably different in many cities. Future epidemiological studies may be able to differentiate PM0.1 and PM2.5 health effects by contrasting cities with different ratios of PM0.1∕PM2.5. In the current study, cities with higher PM0.1∕PM2.5 ratios (ratio greater than 0.10) include Houston, TX, Los Angeles, CA, Bakersfield, CA, Salt Lake City, UT, and Cleveland, OH. Cities with lower PM0.1 to PM2.5 ratios (ratio lower than 0.05) include Lake Charles, LA, Baton Rouge, LA, St. Louis, MO, Baltimore, MD, and Washington, D.C.

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