Fire Influence on Regional to Global Environments and Air Quality (FIREX‐AQ)

Journal of Geophysical Research Atmospheres, Год журнала: 2022, Номер 128(2)

Опубликована: Дек. 30, 2022

Abstract The NOAA/NASA Fire Influence on Regional to Global Environments and Air Quality (FIREX‐AQ) experiment was a multi‐agency, inter‐disciplinary research effort to: (a) obtain detailed measurements of trace gas aerosol emissions from wildfires prescribed fires using aircraft, satellites ground‐based instruments, (b) make extensive suborbital remote sensing fire dynamics, (c) assess local, regional, global modeling fires, (d) strengthen connections observables the ground such as fuels fuel consumption satellite products burned area radiative power. From Boise, ID western were studied with NASA DC‐8 two NOAA Twin Otter aircraft. high‐altitude ER‐2 deployed Palmdale, CA observe some these in conjunction overpasses other Further conducted three mobile laboratories sites, 17 different forecast analyses for fire, air quality climate implications. Salina, KS investigated 87 smaller Southeast in‐situ data collection. Sampling by all platforms designed measure gases aerosols multiple transects capture chemical transformation perform observations smoke plumes under day night conditions. linked consumed power orbital collected during overflights sampling fuels.

Язык: Английский

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

Atmospheric chemistry and physics, Год журнала: 2024, Номер 24(2), С. 929 - 956

Опубликована: Янв. 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

Язык: Английский

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Overview of the Alaskan Layered Pollution and Chemical Analysis (ALPACA) Field Experiment

ACS ES&T Air, Год журнала: 2024, Номер 1(3), С. 200 - 222

Опубликована: Фев. 21, 2024

The Alaskan Layered Pollution And Chemical Analysis (ALPACA) field experiment was a collaborative study designed to improve understanding of pollution sources and chemical processes during winter (cold climate low-photochemical activity), investigate indoor pollution, dispersion as affected by frequent temperature inversions. A number the research goals were motivated questions raised residents Fairbanks, Alaska, where held. This paper describes measurement strategies conditions encountered January February 2022 experiment, reports early examples how measurements addressed goals, particularly those interest residents. Outdoor air showed high concentrations particulate matter pollutant gases including volatile organic carbon species. During events, low winds extremely stable atmospheric trapped below 73 m, an shallow vertical scale. Tethered-balloon-based intercepted plumes aloft, which associated with power plant point through transport modeling. Because cold spend much their time indoors, included quality component, made inside outside house infiltration sources. In absence activities such cooking and/or heating pellet stove, lower than outdoors; however, stove burns often caused higher outdoors. mass-normalized oxidative potential, health-relevant property measured here reactivity dithiothreiol, particles varied source, having less potential per mass particles.

Язык: Английский

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Variability and Time of Day Dependence of Ozone Photochemistry in Western Wildfire Plumes

Environmental Science & Technology, Год журнала: 2021, Номер 55(15), С. 10280 - 10290

Опубликована: Июль 13, 2021

Understanding the efficiency and variability of photochemical ozone (O3) production from western wildfire plumes is important to accurately estimate their influence on North American air quality. A set measurements were made NOAA Twin Otter research aircraft as a part Fire Influence Regional Global Environments Air Quality (FIREX-AQ) experiment. We use zero-dimensional (0-D) box model investigate chemistry driving O3 in modeled plumes. Modeled afternoon reached maximum mixing ratio 140 ± 50 ppbv (average standard deviation) within 20 10 min emission compared 76 12 60 30 evening Afternoon isopleths indicate that near peak NOx efficiency. radical budget describes volatile - organic compound (VOC) sensitivities these displayed rapid transition VOC-sensitive NOx-sensitive chemistry, driven by HOx (=OH + HO2) photolysis nitrous acid (HONO) (48 20% primary HOx) formaldehyde (HCHO) (26 9%) emitted directly fire. Evening exhibit slower caused reduction rates fire emissions. controlled HONO (53 7%), HCHO (18 9%), alkene ozonolysis (17 9%).

Язык: Английский

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Investigating Carbonaceous Aerosol and Its Absorption Properties From Fires in the Western United States (WE‐CAN) and Southern Africa (ORACLES and CLARIFY)

Journal of Geophysical Research Atmospheres, Год журнала: 2021, Номер 126(15)

Опубликована: Июль 16, 2021

Abstract Biomass burning (BB) produces large quantities of carbonaceous aerosol (black carbon and organic aerosol, BC OA, respectively), which significantly degrade air quality impact climate. absorbs radiation, warming the atmosphere, while OA typically scatters leading to cooling. However, some termed brown (BrC), also visible near UV radiation; although, its properties are not well constrained. We explore three aircraft campaigns from important BB regions with different dominant fuel fire types (Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption, Nitrogen [WE‐CAN] in western United States ObseRvations Aerosols above CLouds their intEractionS Cloud‐Aerosol‐Radiation Interactions Forcing Year downwind southern Africa) compare them simulations global chemical transport model, GEOS‐Chem using GFED4s. The model generally captures observed vertical profiles concentrations; however, we find that emissions underestimated Africa. Our comparisons suggest and/or BrC absorption is substantially higher Africa than and, Saleh et al. (2014, https://doi.org/10.1038/ngeo2220 ) FIREX parameterizations based on BC:OA ratio improve model‐observation agreement regions, they do sufficiently differentiate characteristics at short wavelengths. photochemical whitening decreases burden direct radiative effect (annual mean +0.29 W m −2 without +0.08 with). required explain WE‐CAN observations; importance African fires cannot be confirmed. Qualitative OMI index our standard scheme may too fast over

Язык: Английский

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Fine Ash‐Bearing Particles as a Major Aerosol Component in Biomass Burning Smoke

Journal of Geophysical Research Atmospheres, Год журнала: 2022, Номер 127(2)

Опубликована: Янв. 10, 2022

Abstract Biomass burning (BB) events are occurring globally with increasing frequency, and their emissions having more impacts on human health climate. Large ash particles recognized as a BB product major influences soil water environments. However, fine‐ash particles, which have diameters smaller than several microns characteristic morphologies compositions (mainly Ca Mg carbonates), not yet been explicitly considered aerosol component either in field observations or climate models. This study measured samples using transmission electron microscopy (TEM) ion chromatography during the Fire Influence Regional to Global Environments Air Quality (FIREX‐AQ) campaign. We show that significant amounts of fine ash‐bearing transported >100 km from fire sources. Our environmental chamber experiments suggest they can act cloud condensation ice nuclei. also found considerable TEM collected previous campaigns (Biomass Burning Observation Project Megacity Initiative: Local Research Observations). These commonly mixed organic matter make up ∼8% 5% smoke by number mass, respectively, FIREX‐AQ The ash‐mass concentrations approximately five times six greater those black carbon potassium, scaling an estimated global emission 11.6 Tg yr −1 range 8.8–16.3 . Better characterization constraints these will improve measurements strengthen assessments

Язык: Английский

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Airborne Emission Rate Measurements Validate Remote Sensing Observations and Emission Inventories of Western U.S. Wildfires

Environmental Science & Technology, Год журнала: 2022, Номер 56(12), С. 7564 - 7577

Опубликована: Май 17, 2022

Carbonaceous emissions from wildfires are a dynamic mixture of gases and particles that have important impacts on air quality climate. Emissions feed atmospheric models estimated using burned area fire radiative power (FRP) methods rely satellite products. These approaches show wide variability large uncertainties, their accuracy is challenging to evaluate due limited aircraft ground measurements. Here, we present novel method estimate plume-integrated total carbon speciated emission rates unique combination lidar remote sensing aerosol extinction profiles in situ measured constituents. We strong agreement between these aircraft-derived detailed area-based inventory distributes time Geostationary Operational Environmental Satellite FRP observations (Fuel2Fire inventory, slope = 1.33 ± 0.04, r2 0.93, RMSE 0.27). Other more commonly used inventories strongly correlate with but wide-ranging over- under-predictions. A correlation found monoxide those derived the TROPOspheric Monitoring Instrument (TROPOMI) for five coincident sampling windows (slope 0.99 0.18; bias 28.5%). Smoke coefficients (g MJ–1) enable direct estimations primary gas observations, derive values many compounds emitted by temperate forest fuels, including several previously unreported species.

Язык: Английский

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Persistent Influence of Wildfire Emissions in the Western United States and Characteristics of Aged Biomass Burning Organic Aerosols under Clean Air Conditions

Environmental Science & Technology, Год журнала: 2022, Номер 56(6), С. 3645 - 3657

Опубликована: Март 1, 2022

Wildfire-influenced air masses under regional background conditions were characterized at the Mt. Bachelor Observatory (∼2800 m a.s.l.) in summer 2019 to provide a better understanding of aging biomass burning organic aerosols (BBOAs) and their impacts on remote troposphere western United States. Submicron aerosol (PM1) concentrations low (average ± 1σ = 2.2 1.9 μg sm–3), but oxidized BBOAs O/C 0.84) constantly detected throughout study. The BBOA correlated well with black carbon, furfural, acetonitrile comprised above 50% PM1 during plume events when peak concentration reached 18.0 sm–3. Wildfire plumes estimated transport times varying from ∼10 h >10 days identified. showed ΔOA/ΔCO values ranging 0.038 0.122 ppb ppb–1 significant negative relation age, indicating loss relative CO long-range transport. Additionally, increases average sizes seen more aged plumes. mass-based size mode was approximately 700 nm (Dva) most that likely originated Siberia, suggesting aqueous-phase processing This work highlights widespread wildfire emissions have properties, thus climate,

Язык: Английский

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Space-Based Observations of Ozone Precursors within California Wildfire Plumes and the Impacts on Ozone-NO_x-VOC Chemistry

Environmental Science & Technology, Год журнала: 2023, Номер 57(39), С. 14648 - 14660

Опубликована: Сен. 13, 2023

The frequency of wildfires in the western United States has escalated recent decades. Here we examine impacts on ground-level ozone (O3) precursors and O3-NOx-VOC chemistry from source to downwind urban areas. We use satellite retrievals nitrogen dioxide (NO2) formaldehyde (HCHO, an indicator VOC) Tropospheric Monitoring Instrument (TROPOMI) track evolution O3 over California 2018 2020. improved these by updating a priori profiles explicitly accounting for effects smoke aerosols. TROPOMI observations reveal that extensive intense fire 2020 led overall increase statewide annual average HCHO NO2 columns 16% 9%. level offsets anthropogenic NOx emission reduction COVID-19 lockdown. enhancement within plumes is concentrated near regions actively burning, whereas far-reaching, extending areas due secondary production longer-lived VOCs such as ethene. Consequently, larger occurs NOx-limited regions, while greater VOC-limited areas, both contributing more efficient production.

Язык: Английский

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The persistence of smoke VOCs indoors: Partitioning, surface cleaning, and air cleaning in a smoke-contaminated house

Science Advances, Год журнала: 2023, Номер 9(41)

Опубликована: Окт. 13, 2023

Wildfires are increasing in frequency, raising concerns that smoke can permeate indoor environments and expose people to chemical air contaminants. To study transformations evaluate mitigation strategies, we added a test house. Many volatile organic compounds (VOCs) persisted days following the injection, providing longer-term exposure pathway for humans. Two time scales control VOC partitioning: faster one (1.0 5.2 hours) describes reach equilibrium between adsorption desorption processes slower (4.8 21.2 ventilation overtake adsorption-desorption equilibria controlling concentration. These rates imply vapor pressure controls partitioning behavior house plays minor role removing VOCs. However, surface cleaning activities (vacuuming, mopping, dusting) physically removed reservoirs thus reduced concentrations more effectively than portable cleaners persistently window opening.

Язык: Английский

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