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

Journal of Geophysical Research Atmospheres, Journal Year: 2022, Volume and Issue: 128(2)

Published: Dec. 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.

Language: Английский

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Daytime Oxidized Reactive Nitrogen Partitioning in Western U.S. Wildfire Smoke Plumes

Journal of Geophysical Research Atmospheres, Journal Year: 2020, Volume and Issue: 126(4)

Published: Dec. 23, 2020

Abstract The Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption, and Nitrogen (WE‐CAN) deployed the NSF/NCAR C‐130 aircraft in summer 2018 across western U.S. to sample wildfire smoke during its first days of atmospheric evolution. We present a summary subset reactive oxidized nitrogen species (NO y ) plumes sampled pseudo‐Lagrangian fashion. Emissions oxides x = NO + 2 nitrous acid (HONO) are rapidly converted more forms. Within 4 h, ∼86% ΣNO is form peroxy acyl nitrates (PANs) (∼37%), particulate nitrate ( p 3 (∼27%), gas‐phase organic (Org N (g) (∼23%). average e ‐folding time distance ∼90 min ∼40 km, respectively. Nearly no enhancements nitric (HNO were observed fashion, implying HNO ‐limited ammonium (NH formation, with one notable exception that we highlight as case study. also summarize partitioning all samples intercepted WE‐CAN. In above km sea level (ASL), contributions PANs increase altitude. WE‐CAN from multiple fires mixed anthropogenic emissions over California Central Valley. distinguish where appear lead an abundances by factor four contribute additional PAN formation.

Language: Английский

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Sizing response of the Ultra-High Sensitivity Aerosol Spectrometer (UHSAS) and Laser Aerosol Spectrometer (LAS) to changes in submicron aerosol composition and refractive index

Atmospheric measurement techniques, Journal Year: 2021, Volume and Issue: 14(6), P. 4517 - 4542

Published: June 18, 2021

Abstract. We evaluate the sensitivity of size calibrations two commercially available, high-resolution optical particle sizers to changes in aerosol composition and complex refractive index (RI). The Droplet Measurement Technologies Ultra-High Sensitivity Aerosol Spectrometer (UHSAS) TSI, Inc. Laser (LAS) are commonly used instruments for measuring portion distribution with diameters larger than nominally 60–90 nm. Both illuminate particles a laser relate single-particle light scattering intensity count rate measured over wide range angles size-dependent concentration. While block geometry flow system similar each instrument, significant difference between models is wavelength (1054 nm UHSAS 633 LAS) (about 100 times higher UHSAS), which may affect way instrument sizes non-spherical or absorbing aerosols. Here, we challenge LAS laboratory-generated, mobility-size-classified aerosols known chemical quantify response relative that ammonium sulfate (RI 1.52+0i at 532 nm) NIST-traceable polystyrene latex spheres (PSLs RI 1.59+0i 589 nm). inorganic salt species chosen cover real 1.32 1.78, while light-absorbing carbonaceous include fullerene soot, nigrosine dye, humic acid, fulvic acid standards. generally good agreement electrical mobility diameter. However, large undersizing deviations observed low-refractive-index fluoride salts strongly dye soot particles. Polydisperse distributions both fresh aged wildfire smoke from recent Fire Influence on Regional Global Environments Experiment Air Quality (FIREX-AQ) Cloud, Aerosol, Monsoon Processes Philippines (CAMP2Ex) airborne campaigns show contemporaneous sizing time-of-flight mass spectrometric measurements. assess uncertainties by interpolating laboratory curves using previously reported RIs multiple type classifications. These results suggest that, underperform compounds tailpipe emissions measurements, sampling within atmospherically relevant indices likely be sized better ±10 %–20 % uncertainty submicron when calibrated sulfate.

Language: Английский

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Using the Black Carbon Particle Mixing State to Characterize the Lifecycle of Biomass Burning Aerosols

Environmental Science & Technology, Journal Year: 2022, Volume and Issue: 56(20), P. 14315 - 14325

Published: Oct. 6, 2022

The lifecycle of black carbon (BC)-containing particles from biomass burns is examined using aircraft and surface observations the BC mixing state for plume ages ∼15 min to 10 days. Because nonvolatile chemically inert, changes in BC-containing are driven solely by particle coating, which mainly secondary organic aerosol (SOA). coating mass initially increases rapidly (kgrowth = 0.84 h–1), then remains relatively constant 1–2 days as dilution no longer supports further growth, decreases slowly until only ∼30% maximum after (kloss 0.011 h–1). ratio coating-to-core a with 100 nm mass-equivalent diameter core reaches ∼20 few hours drops ∼5 aging. initial increase can be used determine SOA formation rates. slow loss material, not captured global models, comprises dominant fraction these particles. Coating-to-core ratios stratosphere much greater than those free troposphere indicating different lifecycle.

Language: Английский

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Characteristics and evolution of brown carbon in western United States wildfires

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(12), P. 8009 - 8036

Published: June 21, 2022

Abstract. Brown carbon (BrC) associated with aerosol particles in western United States wildfires was measured between July and August 2019 aboard the NASA DC-8 research aircraft during Fire Influence on Regional to Global Environments Air Quality (FIREX-AQ) study. Two BrC measurement methods are investigated, highly spectrally resolved light absorption solvent (water methanol) extracts of collected filters situ bulk particle at three wavelengths (405, 532 664 nm) a photoacoustic spectrometer (PAS). A light-absorption closure analysis for 300 700 nm performed. The combined pure black material, including enhancements due internally mixed materials, plus soluble Mie-predicted factor conversion BrC, compared spectra from power law fit PAS wavelengths. For various parameters used, wavelength roughly 400 they agreed, lower individual component-predicted significantly exceeded higher consistently but more variable. Limitations extrapolation data below 405 missing species low solubility that strongly absorb may account differences. Based measurements closest fires, emission ratio PAS-measured relative monoxide (CO) average 0.13 Mm−1 ppbv−1; ratios also provided. As smoke moved away burning regions, evolution over time observed be complex; enhancement, depletion or constant levels age were all first 8 h after different plumes. Within following emissions, 4-nitrocatechol, well-characterized chromophore commonly found particles, largely depleted BrC. In descending plume where temperature increased by 15 K, 4-nitrocatechol dropped, possibly temperature-driven evaporation, remained unchanged. Evidence reactions ozone, related species, as pathway secondary formation under both high oxides nitrogen (NOx) conditions, while bleached regions ozone NOx, consistent complex behaviors laboratory studies. Although hours is variable, limited number aged (15 30 h) indicate net loss It yet determined how near-field affects characteristics longer timescales spatial scales, its environmental impacts likely greater.

Language: Английский

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

Journal of Geophysical Research Atmospheres, Journal Year: 2022, Volume and Issue: 127(2)

Published: Jan. 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

Language: Английский

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The characterization of long-range transported North American biomass burning plumes: what can a multi-wavelength Mie–Raman-polarization-fluorescence lidar provide?

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(8), P. 5399 - 5414

Published: April 25, 2022

Abstract. This article presents a study of long-range transported biomass burning aerosols (BBA) originated from the North American wildfires in September 2020. The BBA plumes presented this were troposphere and underwent 1–2 weeks aging before arriving at lidar station ATOLL (ATmospheric Observatory LiLle) northern France. A novel lidar-derived dataset, 2α+3β+3δ+ϕ (α: extinction coefficient; β: backscatter δ: particle linear depolarization ratio, i.e., PLDR; ϕ: fluorescence capacity), is provided for characterization BBA. capacity an intensive aerosol parameter describing ability producing when exposed to UV excitation. In our observations, obvious variations parameters, reflecting variability properties, detected. PLDRs varied less than 0.03 all wavelengths 0.15–0.22 0.12–0.16, respectively, 355 532 nm. related Angström exponent was within range −0.3 1.0 × 10−4–4.0 10−4. Lidar ratio as low 24 ± 4 sr (50 8 sr) observed (532) nm on 17–18 September, which lower most previously aged BBAs. These are likely correlated with combustion process, lifting conditions (temperature, humidities, etc.) process. addition, results indicate could act ice nucleating particles tropospheric conditions. channel proves be important added value aerosol–cloud interactions studies, due its high sensitivity. With increase wildfire occurrence intensity, BBAs become more atmospheric component. context, we show potential dataset particles' understanding their role cloud processes.

Language: Английский

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Reducing Aerosol Forcing Uncertainty by Combining Models With Satellite and Within‐The‐Atmosphere Observations: A Three‐Way Street

Reviews of Geophysics, Journal Year: 2023, Volume and Issue: 61(2)

Published: May 4, 2023

Abstract Aerosol forcing uncertainty represents the largest climate overall. Its magnitude has remained virtually undiminished over past 20 years despite considerable advances in understanding most of key contributing elements. Recent work produced modest increases only confidence estimate itself. This review summarizes contributions toward reducing aerosol made by satellite observations, measurements taken within atmosphere, as well modeling and data assimilation. We adopt a more measurement‐oriented perspective than reviews subject assessing strengths limitations each; gaps possible ways to fill them are considered. Currently planned programs supporting advanced, global‐scale surface‐based aerosol, cloud, precursor gas modeling, intensive field campaigns aimed at characterizing underlying physical chemical processes involved, all essential. But addition, new efforts needed: (a) obtain systematic aircraft situ capturing multi‐variate probability distribution functions particle optical, microphysical, properties (and associated estimates), co‐variability with meteorology, for major airmass types; (b) conceive, develop, implement suborbital (aircraft plus surface‐based) program systematically quantifying cloud‐scale microphysics, cloud optical properties, cloud‐related vertical velocities aerosol‐cloud interactions; (c) focus much research on integrating unique measurements, reduce persistent forcing.

Language: Английский

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Dilution impacts on smoke aging: evidence in Biomass Burning Observation Project (BBOP) data

Atmospheric chemistry and physics, Journal Year: 2021, Volume and Issue: 21(9), P. 6839 - 6855

Published: May 5, 2021

Abstract. Biomass burning emits vapors and aerosols into the atmosphere that can rapidly evolve as smoke plumes travel downwind dilute, affecting climate- health-relevant properties of smoke. To date, theory has been unable to explain observed variability in evolution. Here, we use observational data from Burning Observation Project (BBOP) field campaign show initial organic aerosol mass concentrations help predict changes aging markers, number concentration, mean diameter between 40–262 nm. Because measurements are generally >10 min downwind, smaller will have already undergone substantial dilution relative larger lower species at these observations closest fire. The extent which occurred prior first observation is not a directly measurable quantity. We plume serve rough indicator measurement, impacts photochemistry, evaporation, coagulation. Cores higher than edges. By segregating cores edges, find evidence particle aging, coagulation before measurement. further on more oxygenated, while marker for primary biomass emissions decreased abundance compared cores. Finally, attempt decouple roles physical age since emission by performing multivariate linear regression various (composition, size) two factors.

Language: Английский

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Rapid transformation of ambient absorbing aerosols from West African biomass burning

Atmospheric chemistry and physics, Journal Year: 2021, Volume and Issue: 21(12), P. 9417 - 9440

Published: June 21, 2021

Abstract. Seasonal biomass burning (BB) over West Africa is a globally significant source of carbonaceous particles in the atmosphere, which have important climate impacts but are poorly constrained. Here, evolution smoke aerosols emitted from flaming-controlled agricultural waste and wooded savannah Senegal region was characterized timescale half-day advection during MOYA-2017 (Methane Observation Yearly Assessment-2017) aircraft campaign. Plumes such fire types rich black carbon (BC) emissions. Concurrent measurements chemical composition, organic aerosol (OA) oxidation state, bulk size BC mixing state reveal that BB submicron changed dramatically with time. Various optical properties (e.g. absorption Ångström exponent – AAE mass coefficients MACs) also evolved ageing. In this study, brown (BrC) minor fractional component freshly (< 0.5 h), increasing particle age indicates BrC formation dominated any loss process first ∼ 12 h plume transport. Using different methods, contribution to total showed an trend time 18 %–31 % at wavelength 405 nm after The generated found be positively correlated oxygenated low-volatility OA, likely evaporated primary OA secondary formation. We compared previous field studies mainly focused on emissions smouldering fires, shown high net upon This study suggests initial stage enhancement smoke. Secondary processing dominant contributor production region, contrast emission previously reported other studies. normalized (MACmeas-BC) enhanced ageing due lensing effect increasingly thick coatings by BrC. absorption, represented (EAbs-MAC), estimated timescales hours. provides novel results. comparisons between imply absorbing (BC BrC) varies combustion conditions. Different treatments fires their downwind should considered when modelling regional radiative forcing. These observational results will very for predicting effects regions controlled flaming savannah-like fuels.

Language: Английский

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