Aerosols in atmospheric chemistry and biogeochemical cycles of nutrients

Environmental Research Letters, Journal Year: 2018, Volume and Issue: 13(6), P. 063004 - 063004

Published: April 10, 2018

Atmospheric aerosols have complex and variable compositions properties. While scientific interest is centered on the health climatic effects of atmospheric aerosols, insufficient attention given to their involvement in multiphase chemistry that alters contribution as carriers nutrients ecosystems. However, there experimental proof nutrient equilibria both land marine ecosystems been disturbed during Anthropocene period.

Language: Английский

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Sources and Secondary Production of Organic Aerosols in the Northeastern United States during WINTER

Journal of Geophysical Research Atmospheres, Journal Year: 2018, Volume and Issue: 123(14), P. 7771 - 7796

Published: July 27, 2018

Abstract Most intensive field studies investigating aerosols have been conducted in summer, and thus, wintertime aerosol sources chemistry are comparatively poorly understood. An mass spectrometer was flown on the National Science Foundation/National Center for Atmospheric Research C‐130 during Wintertime INvestigation of Transport, Emissions, Reactivity (WINTER) 2015 campaign northeast United States. The fraction boundary layer submicron that organic (OA) about a factor 2 smaller than 2011 summertime study similar region. However, OA measured WINTER almost as oxidized several other warmer months year. Fifty‐eight percent oxygenated (secondary), 42% primary (POA). Biomass burning (likely from residential heating) ubiquitous accounted 33% mass. Using nonvolatile POA, one two default secondary (SOA) formulations GEOS‐Chem (v10‐01) shows very large underpredictions SOA O/C (5×) overprediction POA (2×). We strongly recommend against using formulation future studies. Semivolatile an alternative GEOS‐Chem, or simplified parameterization (SIMPLE) were closer to observations, although still with substantial differences. A case urban outflow metropolitan New York City showed consistent amount normalized rate added (due formation) compared summer studies, proceeding more slowly due lower OH concentrations. box model SIMPLE perform similarly Los Angeles, underprediction at ages <6 hr, suggesting fast might be missing models.

Language: Английский

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Chemical Characterization of Highly Functionalized Organonitrates Contributing to Night-Time Organic Aerosol Mass Loadings and Particle Growth

Environmental Science & Technology, Journal Year: 2019, Volume and Issue: 53(3), P. 1165 - 1174

Published: Jan. 7, 2019

Reactions of volatile organic compounds (VOC) with NO3 radicals and reactive intermediates oxidized VOC NOx can lead to the formation highly functionalized organonitrates (ON). We present quantitative chemical information on ON contributing high night-time aerosol (OA) mass concentrations measured during July–August 2016 in a rural area southwest Germany. A filter inlet for gases aerosols coupled high-resolution time-of-flight ionization spectrometer (FIGAERO-HR-ToF-CIMS) was used analyze molecular composition both gas particle phase. find larger contributions OA night. Identified are functionalized, 4 12 oxygen atoms. The diel patterns 5, 7, 10, or 15 carbon atoms per molecule vary, indicating corresponding behavior their potential precursor VOC. temporal after sunset correlates that number concentration ultrafine particles, role new (NPF) regularly observed at this location. estimate an contribution 18–25% increase newly formed particles sunset. Our study provides insights into atmosphere anthropogenic emissions SOA where biogenic dominate.

Language: Английский

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Secondary Organic Aerosol (SOA) from Nitrate Radical Oxidation of Monoterpenes: Effects of Temperature, Dilution, and Humidity on Aerosol Formation, Mixing, and Evaporation

Environmental Science & Technology, Journal Year: 2017, Volume and Issue: 51(14), P. 7831 - 7841

Published: June 19, 2017

Nitrate radical (NO3) oxidation of biogenic volatile organic compounds (BVOC) is important for nighttime secondary aerosol (SOA) formation. SOA produced at night may evaporate the following morning due to increasing temperatures or dilution semivolatile compounds. We isothermally dilute products from limonene+NO3 reaction 25 °C and observe negligible evaporation via dilution. The yields are approximately constant (∼174%) range 81 148% 40 °C. Based on difference in between two temperatures, we calculated an effective enthalpy vaporization 117-237 kJ mol-1. can be as much 50% lower compared However, when formed heated °C, only about 20% evaporates, which could indicate a resistance evaporation. To better understand this, probe possibility that β-pinene+NO3 reactions highly viscous. demonstrate particle morphology dependent whether limonene before during formation β-pinene. This present even high relative humidity (∼70%).

Language: Английский

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Chemical composition and hydrolysis of organic nitrate aerosol formed from hydroxyl and nitrate radical oxidation of α-pinene and β-pinene

Atmospheric chemistry and physics, Journal Year: 2019, Volume and Issue: 19(19), P. 12749 - 12766

Published: Oct. 11, 2019

Abstract. Atmospheric organic nitrate (ON) is thought to play a crucial role in the formation potential of ozone and aerosol, which are leading air pollutants concern across world. Limited fundamental knowledge understanding life cycles ON currently hinder ability quantitatively assess its impacts on these pollutants. Although hydrolysis considered an important loss mechanism based prior field measurement studies, this process for atmospherically relevant has not been well constrained by laboratory studies. In comprehensive study, we investigated chemical composition particulate (pON) formed from oxidation α-pinene β-pinene hydroxyl (OH⚫) radicals (NO3⚫). For pON that undergoes hydrolysis, lifetime determined be no more than 30 min all systems explored. This significantly shorter those reported previous chamber studies (i.e., 3–6 h) but consistent with bulk solution 0.02–8.8 h). The discrepancy appears stem choice proxy used estimate lifetime. measured hydrolyzable fractions (FH) + OH⚫, NO3⚫, NO3⚫ 23 %–32 %, 27 %–34 9 %–17 %–15 respectively. While very low FH system expected OH⚫ surprisingly lower predicted past Overall, as obtained study serve experimentally parameters required regional global transport models accurately evaluate nitrogen budget aerosol.

Language: Английский

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Efficient N&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; uptake and NO&lt;sub&gt;3&lt;/sub&gt; oxidation in the outflow of urban Beijing

Atmospheric chemistry and physics, Journal Year: 2018, Volume and Issue: 18(13), P. 9705 - 9721

Published: July 10, 2018

Abstract. Nocturnal reactive nitrogen compounds play an important role in regional air pollution. Here we present the measurements of dinitrogen pentoxide (N2O5) associated with nitryl chloride (ClNO2) and particulate nitrate (pNO3-) at a suburban site Beijing summer 2016. High levels N2O5 ClNO2 were observed outflow urban masses, 1 min average maxima 937 2900 pptv, respectively. The uptake coefficients, γ, yield, f, experimentally determined from parameters. coefficient ranged 0.012 to 0.055, 0.034 ± 0.018, which is upper range previous field studies reported North America Europe but moderate value China Plain (NCP), reflects efficient heterogeneous processes Beijing. yield exhibited high variability, 0.50 unity 0.73 0.25. concentration radical (NO3) was calculated assuming that thermal equilibrium between NO3 maintained. In NOx-rich oxidation nocturnal biogenic volatile organic (BVOCs) dominated by rather than O3. production rate (ON) via + BVOCs significant, 0.10 0.07 ppbv h−1. We highlight importance VOCs formation ON subsequent secondary aerosols

Language: Английский

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Size-dependent influence of NO _x on the growth rates of organic aerosol particles

Science Advances, Journal Year: 2020, Volume and Issue: 6(22)

Published: May 27, 2020

NO x is important for particle growth as it can participate in HOM formation and alter the volatility distribution.

Language: Английский

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Transformation of logwood combustion emissions in a smog chamber: formation of secondary organic aerosol and changes in the primary organic aerosol upon daytime and nighttime aging

Atmospheric chemistry and physics, Journal Year: 2016, Volume and Issue: 16(20), P. 13251 - 13269

Published: Oct. 28, 2016

Abstract. Organic aerosols (OA) derived from small-scale wood combustion emissions are not well represented by current inventories and models, although they contribute substantially to the atmospheric particulate matter (PM) levels. In this work, a 29 m3 smog chamber in ILMARI facility of University Eastern Finland was utilized investigate formation secondary organic aerosol (SOA) modern masonry heater commonly used northern Europe. Emissions were oxidatively aged for variety dark (i.e., O3 NO3) UV OH) conditions, with OH concentration levels (0.5–5) × 106 molecules cm−3, achieving equivalent aging up 18 h. An mass spectrometer characterized direct OA SOA formed three species (birch, beech spruce) using two ignition processes (fast VOC-to-NOx ratio 3 slow 5).Dark increased fraction average productions 2.0 times initial loadings. enhancement found be higher compared fast conditions. Positive matrix factorization (PMF) separate SOA, primary (POA) their subgroups total spectra. PMF analysis identified POA factors that correlated major oxidizers: ozone, nitrate radical radical. Organonitrates (ONs) observed emitted directly additionally during oxidation via NO3 radicals (dark aging), suggesting may significant ON source. oxidized after ozone addition, forming POA, 7 h more than 75 % original transformed. This process involve evaporation homogeneous gas-phase as heterogeneous matter. The results generally prove logwood burning subject intensive chemical processing atmosphere, timescale these transformations is relatively short, i.e., hours.

Language: Английский

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Transition from high- to low-NOx control of night-time oxidation in the southeastern US

Nature Geoscience, Journal Year: 2017, Volume and Issue: 10(7), P. 490 - 495

Published: June 26, 2017

Language: Английский

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Biomass-burning-derived particles from a wide variety of fuels – Part 1: Properties of primary particles

Atmospheric chemistry and physics, Journal Year: 2020, Volume and Issue: 20(3), P. 1531 - 1547

Published: Feb. 7, 2020

Abstract. Relationships between various optical, physical, and chemical properties of biomass-combustion-derived particles are characterized for produced in the laboratory from a wide range fuels burn conditions. The modified combustion efficiency (MCE), commonly used to parameterize biomass particle emissions properties, is shown generally have weak predictive capabilities, especially more efficient There is, however, strong relationship many intensive optical (e.g., single-scatter albedo, Ångström absorption exponent, mass efficiency) organic aerosol-to-black carbon ([OA] ∕ [BC]) ratio over wider than previously considered (0.3 105). brown (BrC, i.e., light-absorbing carbon) also vary with [OA] [BC]. Coating-induced enhancements (i.e., “lensing” effects) contribute only minor amount BC all burns despite some producing having large ensemble-average coating-to-core ratios. BC–OA mixing state varies strongly [BC]; fraction OA that internally mixed decreases [BC] while relative coated on increases. In contrast, there little bulk [BC], O : C H atomic ratios abundance key marker ion (m/z=60, linked levoglucosan) showing no dependence both nitrate volatility do depend Neither total nor BC-specific size distributions exhibit any clear conditions or although perhaps fuel type. Overall, our results expand existing knowledge new understanding emitted combustion.

Language: Английский

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