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

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(2), P. 929 - 956

Published: Jan. 23, 2024

Abstract. Extensive airborne measurements of non-methane organic gases (NMOGs), methane, nitrogen oxides, reduced 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 board 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 parts million by volume (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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Influence of Wildfire on Urban Ozone: An Observationally Constrained Box Modeling Study at a Site in the Colorado Front Range

Environmental Science & Technology, Journal Year: 2023, Volume and Issue: 57(3), P. 1257 - 1267

Published: Jan. 6, 2023

Increasing trends in biomass burning emissions significantly impact air quality North America. Enhanced mixing ratios of ozone (O3) urban areas during smoke-impacted periods occur through transport O3 produced within the smoke or pyrogenic volatile organic compounds (PVOCs) with nitrogen oxides (NOx = NO + NO2) to enhance local production. Here, we analyze a set detailed chemical measurements, including carbon monoxide (CO), NOx, and speciated (VOCs), evaluate effects transported from relatively long-range fires on measured at site Boulder, Colorado, summer 2020. Relative smoke-free period, CO, background O3, OH reactivity, total VOCs increased both periods, but NOx remained approximately constant. These observations are consistent PVOCs (comprised primarily oxygenates) not influence upwind area. Box-model calculations show that production all three was NOx-sensitive regime. Consequently, this locally similar insensitive increase PVOCs. However, calculated sensitivities substantially transition NOx-saturated (VOC-sensitive) regimes. results suggest (1) is main driver for increases (2) may cause an additional areas. Additional VOC measurements impacted necessary broadly quantify wildfire develop effective mitigation strategies.

Language: Английский

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Feasibility of robust estimates of ozone production rates using a synergy of satellite observations, ground-based remote sensing, and models

Atmospheric chemistry and physics, Journal Year: 2025, Volume and Issue: 25(4), P. 2061 - 2086

Published: Feb. 18, 2025

Abstract. Ozone pollution is secondarily produced through a complex, non-linear chemical process. Our understanding of the spatiotemporal variations in photochemically ozone (i.e., PO3) limited to sparse aircraft campaigns and transport models, which often carry significant biases. Hence, we present novel satellite-derived PO3 product informed by bias-corrected TROPOspheric Monitoring Instrument (TROPOMI) HCHO, NO2, surface albedo data, various models. These data are integrated into parameterization that relies on HCHO / jNO2, jO1D. Despite its simplicity, it can reproduce ∼ 90 % variance observationally constrained PO3, with minimal biases moderately highly polluted regions. We map across regions respect July 2019 at 0.1° × spatial resolution, revealing accelerated values (> 8 ppbv h−1) for numerous cities throughout Asia Middle East, resulting from elevated precursors enhanced photochemistry. In Europe United States, such high levels only detected over Benelux, Los Angeles, New York City. maxima observed seasons attributed changes photolysis rates, chemistry, fluctuations NO2. Satellite errors result moderate (10 %–20 %) estimates monthly average basis, while these exceed 50 clean areas under low light conditions. Using current algorithm, demonstrate satellite provide valuable information robust estimation. This capability expands future research application address scientific questions about locally hotspots, seasonality, long-term trends.

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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Constraining emissions of volatile organic compounds from western US wildfires with WE-CAN and FIREX-AQ airborne observations

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(10), P. 5969 - 5991

Published: May 31, 2023

Abstract. The impact of biomass burning (BB) on the atmospheric burden volatile organic compounds (VOCs) is highly uncertain. Here we apply GEOS-Chem chemical transport model (CTM) to constrain BB emissions in western USA at ∼ 25 km resolution. Across three emission inventories widely used CTMs, inventory–inventory comparison suggests that totals 14 modeled VOC agree with each other within 30 %–40 %. However, for individual VOCs can differ by a factor 1–5, driven regionally averaged ratios (ERs, reflecting both assigned ERs specific biome and vegetation classifications) across inventories. We further evaluate simulations aircraft observations made during WE-CAN (Western Wildfire Experiment Cloud Chemistry, Aerosol Absorption Nitrogen) FIREX-AQ (Fire Influence Regional Global Environments Air Quality) field campaigns. Despite being different global or applying various injection height assumptions, model–observation underpredict observed vertical profiles 3–7. shows small no bias most species low-/no-smoke conditions. thus attribute negative biases mostly underestimated these Tripling reproduces primary compounds, i.e., CO, propane, benzene, toluene. it less significant improvements oxygenated VOCs, particularly formaldehyde, formic acid, acetic lumped ≥ C3 aldehydes, suggesting missing secondary sources BB-impacted environments. underestimation likely attributable underpredicted amounts effective dry matter burned, rather than errors fire detection, height, ERs, as constrained ground measurements. cannot rule out potential sub-grid uncertainties (i.e., not able fully resolve plumes) nested which could explain partially, though back-of-the-envelope calculation evaluation using longer-term measurements help support argument burned underestimation. total implemented only account half 161 measured (∼ 75 versus 150 ppb ppm−1). This reveals amount reactive carbon Considering (× 3) unmodeled 2), infer contributed 10 % 2019 45 2018 (240 2040 Gg C) flux two seasons, compared 1 %–10 standard GEOS-Chem.

Language: Английский

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Emissions and Atmospheric Chemistry of Furanoids from Biomass Burning: Insights from Laboratory to Atmospheric Observations

ACS Earth and Space Chemistry, Journal Year: 2024, Volume and Issue: 8(5), P. 857 - 899

Published: April 8, 2024

Furanoids are a class of reactive volatile organic compounds that major products from the pyrolysis and combustion biomass polymers, including cellulose, hemicellulose, lignin. Biomass burning is an atmospheric source furanoids increasing in frequency intensity throughout regions world. Once emitted to atmosphere, may react with oxidants form secondary pollutants hazardous human health, ozone (O3) aerosol (SOA). This review comprehensive assessment literature between 1977 present describing emissions fate wild, prescribed, domestic fires. The organized by presenting physical properties key first, followed summary biopolymer reactions lead furanoid formation. Next, factors compiled across typical fuels consumed highlight species smoke. We next available kinetic degradation mechanism data characterize reaction rates, gas-phase products, SOA formed as result OH, NO3, O3, Cl radicals. then describe studies have focused on evaluating chemistry their impacts air quality using combination field observations model simulations. conclude perspective identifies future research directions would address gaps improve understanding processes.

Language: Английский

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Midlatitude Ozone Depletion and Air Quality Impacts from Industrial Halogen Emissions in the Great Salt Lake Basin

Environmental Science & Technology, Journal Year: 2023, Volume and Issue: 57(5), P. 1870 - 1881

Published: Jan. 25, 2023

We report aircraft observations of extreme levels HCl and the dihalogens Cl2, Br2, BrCl in an industrial plume near Great Salt Lake, Utah. Complete depletion O3 was observed concurrently with halogen enhancements as a direct result photochemically produced radicals. Observed fluxes for HCl, NOx agreed facility-reported emissions inventories. Bromine are not required to be reported inventory, but estimated 173 Mg year-1 Br2 949 BrCl, representing major uncounted oxidant source. A zero-dimensional photochemical box model reproduced depletions demonstrated that bromine radical cycling principally responsible rapid depletion. Inclusion both 3D chemical showed significant increases oxidants particulate matter (PM2.5) populated regions Lake Basin, where winter PM2.5 is among most severe air quality issues U.S. The shows regional 10%-25% attributable this single source, demonstrating impact underreported on oxidation sources within urban area western

Language: Английский

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Investigation of Ozone Formation Chemistry during the Salt Lake Regional Smoke, Ozone, and Aerosol Study (SAMOZA)

ACS Earth and Space Chemistry, Journal Year: 2023, Volume and Issue: 7(12), P. 2521 - 2534

Published: Nov. 29, 2023

Salt Lake City (SLC), UT, is an urban area where ozone (O3) concentrations frequently exceed health standards. This study uses observationally constrained photochemical box model to investigate the drivers of O3 production during Regional Smoke, Ozone, and Aerosol Study (SAMOZA), which took place from August September 2022 in SLC. During SAMOZA, a suite volatile organic compounds (VOCs), oxides nitrogen (NOx), other parameters were measured at Utah Technical Center, high-NOx site core. We examined four high-O3 cases: 4 3, 11, 12 September, classified as nonsmoky weekday, weekend day with minimal smoke influence, smoky day, respectively. The modeled on 3 was highly sensitive VOCs insensitive NOx reductions ≤50%. Box results suggest that directly emitted formaldehyde contributed rapid increase morning September. Model sensitivity tests for 11–12 indicated smoke-emitted VOCs, especially aldehydes, had much larger impact than and/or anthropogenic VOCs. On 11 enhanced model-predicted maximum daily 8 h average by 21 13 parts per billion (ppb), Overall, our regionwide VOC least 30–50% or 60% are needed bring SLC into compliance national standard 70 ppb.

Language: Английский

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Evaluating Phoenix Metropolitan Area Ozone Behavior Using Ground-Based Sampling, Modeling, and Satellite Retrievals

Atmosphere, Journal Year: 2024, Volume and Issue: 15(5), P. 555 - 555

Published: April 30, 2024

An oxidizing and harmful pollutant gas, tropospheric ozone is a product of complex set photochemical reactions that can make it difficult to enact effective control measures. A better understanding its precursors including volatile organic compounds (VOCs) nitrogen oxides (NOx) their spatial distribution enable policymakers focus efforts. In this study we used low-cost sensors (LCSs) increase the resolution an existing NO2 monitoring network in addition VOC sampling understand summer formation Maricopa County, Arizona, observed afternoon O3 values at downwind sites were significantly correlated, ~0.27, morning × rate urban sites. Additionally, looked impact wildfire smoke on exceedances compared non-smoke days days. The average was approximately 20% higher than days, however, concentration multiplied by estimated photolysis (NO2 rate) only 2% Finally, evaluated sensitivity region calculating HCHO/NO2 ratios using three different datasets: ground, satellite, model. Although satellite dataset produced other datasets, when proper regime thresholds are applied datasets consistently show transition VOC-limited production regimes over Phoenix metro area. This suggests need implement more emission controls order reach attainment county.

Language: Английский

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An investigation of petrochemical emissions during KORUS-AQ: Ozone production, reactive nitrogen evolution, and aerosol production

Elementa Science of the Anthropocene, Journal Year: 2022, Volume and Issue: 10(1)

Published: Jan. 1, 2022

Emissions and secondary photochemical products from the Daesan petrochemical complex (DPCC), on west coast of South Korea, were measured NASA DC-8 research aircraft during Korea-United States Air Quality campaign in 2016. The chemical evolution emissions was examined utilizing near-source downwind plume transects. Small alkenes, such as ethene (C2H4), propene (C3H6), 1,3-butadiene (C4H6), dominated hydroxyl (OH) radical reactivity near source region. oxidation these alkenes plumes led to efficient conversion nitrogen oxides (NOx) nitric acid (HNO3), peroxycarboxylic anhydrides (PANs), alkyl nitrates (ANs), where sum speciated reactive contributes more than 80% NOy within a few hours. Large enhancements short-lived NOx products, hydroxy (HNs) peroxyacrylic anhydride, observed, conjunction with high ozone levels up 250 ppb, which are attributed 1,3-butadiene. Instantaneous production rates, P(O3), DPCC ranged 9 24 ppb h−1, higher those over Seoul. Ozone efficiencies 6 10 lower contributions instantaneous organic aerosol (SOA) rate, P(SOA), estimated be comparable common SOA precursors aromatics at intermediate distances DPCC. A model case study constrained an extensive set observations provided diagnostic chemistry. simulated chemistry reproduced observed compounds, PANs HNs well rate efficiency production. peroxy (PNs) budget included large (approximately 30%) unmeasured PNs including peroxyhydroxyacetic anhydride peroxybenzoic anhydride. large, predicted PAN compounds suggest their potential importance plumes. One unique feature is substantial contribution potentially This work suggests that reductions small alkene, especially 1,3-butadiene, should priority for reducing ozone.

Language: Английский

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