A Review of Measurements and Model Simulations of Atmospheric Nitrous Acid

Atmospheric Environment, Journal Year: 2025, Volume and Issue: unknown, P. 121094 - 121094

Published: Feb. 1, 2025

Language: Английский

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Comparison of airborne measurements of NO, NO₂, HONO, NO_y, and CO during FIREX-AQ

Atmospheric measurement techniques, Journal Year: 2022, Volume and Issue: 15(16), P. 4901 - 4930

Published: Aug. 29, 2022

Abstract. We present a comparison of fast-response instruments installed onboard the NASA DC-8 aircraft that measured nitrogen oxides (NO and NO2), nitrous acid (HONO), total reactive odd (measured both as (NOy) from sum individually species (ΣNOy)), carbon monoxide (CO) in troposphere during 2019 Fire Influence on Regional to Global Environments Air Quality (FIREX-AQ) campaign. By targeting smoke summertime wildfires, prescribed fires, agricultural burns across continental United States, FIREX-AQ provided unique opportunity investigate measurement accuracy concentrated plumes where hundreds coexist. Here, we compare NO measurements by chemiluminescence (CL) laser-induced fluorescence (LIF); NO2 CL, LIF, cavity-enhanced spectroscopy (CES); HONO CES iodide-adduct chemical ionization mass spectrometry (CIMS); CO tunable diode laser absorption (TDLAS) integrated cavity output (ICOS). Additionally, NOy using CL instrument were compared with ΣNOy (= + nitric (HNO3) acyl peroxy nitrates (APNs) submicrometer particulate nitrate (pNO3)). Other not included they either contributed minimally it (e.g., C1–C5 alkyl nitrates, nitryl chloride (ClNO2), dinitrogen pentoxide (N2O5)) or higher oxidized (NO3), non-acyl peroxynitrates, coarse-mode aerosol nitrate). The intercomparisons demonstrate following points: (1) LIF agreed well within uncertainties but potentially reduced time response for instrument; (2) uncertainties, was average 10 % higher; (3) CIMS highly correlated each fire plume transect, correlation slope vs. all 1 Hz data 1.8, which attribute reduction sensitivity high-temperature environments; (4) budget closure demonstrated flights combined 25 %. However, used fluid dynamic flow model estimate pNO3 sampling fraction through inlet variable one flight another ranged between 0.36 0.99, meaning approximately 0 %–24 may have been unaccounted be due unmeasured such organic nitrates; (5) ICOS TDLAS systematic offset averaged 2.87 ppbv; (6) integrating followed fitting values improved independent measurements.

Language: Английский

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Multiple Impacts of Aerosols on O₃ Production Are Largely Compensated: A Case Study Shenzhen, China

Environmental Science & Technology, Journal Year: 2022, Volume and Issue: 56(24), P. 17569 - 17580

Published: Dec. 6, 2022

Tropospheric ozone (O3) is a harmful gas compound to humans and vegetation, it also serves as climate change forcer. O3 formed in the reactions of nitrogen oxides volatile organic compounds (VOCs) with light. In this study, an pollution episode encountered Shenzhen, South China 2018 was investigated illustrate influence aerosols on local production. We used box model comprehensive heterogeneous mechanisms empirical prediction photolysis rates reproduce episode. Results demonstrate that aerosol light extinction NO2 showed comparable but opposite signs Hence, from different processes largely counteracted. Sensitivity tests suggest production increases further reduction while continued NOx finally shifts NOx-limited regime respect traditional O3-NOx-VOC sensitivity. Our results shed role highlight mitigation not only limiting helping ease particulate nitrate, path for cocontrol fine particle pollution.

Language: Английский

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Unexpected deterioration of O3 pollution in the South Coast Air Basin of California: The role of meteorology and emissions

Environmental Pollution, Journal Year: 2023, Volume and Issue: 330, P. 121728 - 121728

Published: April 26, 2023

Language: Английский

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Air Quality Data Approach for Defining Wildfire Influence: Impacts on PM_2.5, NO₂, CO, and O₃ in Western Canadian Cities

Environmental Science & Technology, Journal Year: 2021, Volume and Issue: 55(20), P. 13709 - 13717

Published: Oct. 5, 2021

As the climate warms, it is recognized that wildfires are increasing in size and frequency. The negative effects of on air quality well documented, especially commonly monitored atmospheric pollutants such as PM2.5, NO2, CO, O3. However, not clear how frequently influence urban relative to traffic industrial pollutants. To understand impact quality, we have established an automated method identify wildfire-influenced ambient measurements. trajectory-fire interception (TFIM) compares hybrid single-particle Lagrangian integrated trajectory (HYSPLIT) back-trajectories from monitoring station satellite imagery fire "hot-spots" determine number interceptions occur. From local PM2.5 measurements, defined a period occur if count ≥20. TFIM wildfire identification favorably with Environment Climate Change Canada's smoke forecast, FireWork, BlueSky trajectory-based forecast. Using TFIM, studied periods O3 2001 2019 Western Canadian areas. We show elevated concentrations CO but decreasing baseline NO2 over time results relatively greater these pollutants, which emphasizes changing importance quality.

Language: Английский

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Aging of Volatile Organic Compounds in October 2017 Northern California Wildfire Plumes

Environmental Science & Technology, Journal Year: 2022, Volume and Issue: 56(3), P. 1557 - 1567

Published: Jan. 17, 2022

In the western United States, number and severity of large wildfires have been growing for decades. Biomass burning (BB) is a major source volatile organic compounds (VOCs) to atmosphere both globally regionally. Following emission, BB VOCs are oxidized while being transported downwind, producing ozone, secondary aerosols, hazardous VOCs. this research, we measured using proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) in an urban area 55–65 km downwind October 2017 Northern California wildfires. Nonaromatic oxygenated were dominant component measured. smoke plumes, account 70–75% total observed carbon, with remainder particulate matter (with diameter <2.5 μm, PM2.5). We show that correlation furan (primary VOC) maleic anhydride (secondary can indicate origin This was further confirmed by diurnal variations their concentration-weighted trajectories. Oxidation during transport consumed highly reactive including benzenoids, furanoids, terpenoids produced more Furthermore, wildfire altered ozone formation regime raised O3 levels San Francisco Bay Area.

Language: Английский

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Photochemical evolution of the 2013 California Rim Fire: synergistic impacts of reactive hydrocarbons and enhanced oxidants

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(6), P. 4253 - 4275

Published: April 1, 2022

Abstract. Large wildfires influence regional atmospheric composition, but chemical complexity challenges model predictions of downwind impacts. Here, we elucidate key connections within gas-phase photochemistry and assess novel processes via a case study the 2013 California Rim Fire plume. Airborne in situ observations, acquired during NASA Studies Emissions, Atmospheric Composition, Clouds Climate Coupling by Regional Surveys (SEAC4RS) mission, illustrate evolution volatile organic compounds (VOCs), oxidants, reactive nitrogen over 12 h aging. Measurements show rapid formation ozone peroxyacyl nitrates (PNs), sustained peroxide production, prolonged enhancements oxygenated VOCs oxides (NOx). Observations Lagrangian trajectories constrain 0-D puff that approximates plume photochemical history provides framework for evaluating process interactions. Simulations examine effects (1) previously unmeasured identified recent laboratory studies (2) emissions secondary production nitrous acid (HONO). Inclusion estimated leads to 250 % increase OH reactivity 70 radical VOC photolysis. HONO amplifies cycling serves as NOx source, although impacts depend on how is introduced. The addition initial (representing primary emissions) or particulate nitrate photolysis while heterogeneous conversion NO2 suppresses formation. Analysis initiation rates suggests major exceeding when averaged first 2 Ozone chemistry transitions from sensitive hour aging, with both contributing significantly termination. To simulate smoke accurately, models should simultaneously account full pool all relevant oxidant sources.

Language: Английский

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Parameterizations of US wildfire and prescribed fire emission ratios and emission factors based on FIREX-AQ aircraft measurements

Published: July 5, 2023

Abstract. Extensive airborne measurements of non-methane organic gases (NMOGs), methane, nitrogen oxides, reduced nitrogen-species, and aerosol emissions from US wild prescribed fires were conducted during the 2019 NOAA/NASA Fire Influence on Regional to Global Environments Air Quality campaign (FIREX-AQ). Here, we report atmospheric enhancement ratios (ERs) inferred emission factors (EFs) for compounds measured onboard NASA DC-8 research aircraft nine wildfires one fire, which encompass a range vegetation types. We use photochemical proxies identify young smoke reduce effects chemical degradation our calculations. ERs EFs calculated FIREX-AQ observations agree within factor 2 with values reported previous laboratory field studies more than 80 % carbon- nitrogen-containing species. Wildfire are parameterized based correlations sum NMOGs reactive oxides (NOy) modified combustion efficiency (MCE) as well other signatures indicative flaming/smoldering combustion, including carbon monoxide (CO), dioxide (NO2), black aerosol. The primary NMOG correlates MCE an R2 0.68 slope -296 ± 51 g kg-1, consistent studies. mixing CO 0.98 137 4 ppbv per ppmv CO, demonstrating that can be estimated CO. Individual species correlate better NO2, NOy, More half NOy in fresh plumes is NO2 0.95 ratio 0.55 0.05 ppbv-1, highlighting fast photochemistry had already occurred sampled fire plumes. follows trends observed experiments increases exponentially MCE, due increased key at higher flaming combustion. These parameterizations will provide accurate boundary conditions modeling satellite plume chemistry evolution predict downwind formation secondary pollutants, ozone

Language: Английский

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Emission Factors for Crop Residue and Prescribed Fires in the Eastern US During FIREX‐AQ

Journal of Geophysical Research Atmospheres, Journal Year: 2023, Volume and Issue: 128(18)

Published: Sept. 2, 2023

Abstract Agricultural and prescribed burning activities emit large amounts of trace gases aerosols on regional to global scales. We present a compilation emission factors (EFs) ratios from the eastern portion Fire Influence Regional Global Environments Air Quality (FIREX‐AQ) campaign in 2019 United States, which sampled crop residues other fire fuels. FIREX‐AQ provided comprehensive chemical characterization 53 residue 22 fires. Crop burned at different modified combustion efficiencies (MCE), with corn higher MCE than fuel types. Prescribed fires lower (<0.90) is typical, while grasslands (0.90) normally observed due moist, green, growing season Most non‐methane volatile organic compounds (NMVOCs) were significantly anticorrelated except for ethanol NMVOCs that measured less certainty. identified 23 species where differed by more 50% same MCE. EFs greater related agricultural use composition as well oxygenated possibly presence metals such potassium. monoterpenes (5×). average generally agreed previous study US but had disagreements compilations. observations show importance regionally‐specific fuel‐specific first steps reduce uncertainty modeling air quality impacts emissions.

Language: Английский

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Formation of Ozone and PM_2.5 in Smoke from Prescribed Burning in the Southeastern United States

ACS ES&T Air, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 28, 2025

Language: Английский

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