Spatially Resolved Photochemistry Impacts Emissions Estimates in Fresh Wildfire Plumes

Geophysical Research Letters, Journal Year: 2021, Volume and Issue: 48(23)

Published: Nov. 17, 2021

Abstract Wildfire emissions affect downwind air quality and human health. Predictions of these impacts using models are limited by uncertainties in chemical evolution smoke plumes. Using high‐time‐resolution aircraft measurements, we illustrate spatial variations that can exist within a plume due to differences the photochemical environment. Horizontal vertical crosswind gradients dilution‐corrected mixing ratios were observed midday plumes for reactive compounds their oxidation products, such as nitrous acid, catechol, ozone, likely faster photochemistry optically thinner edges relative darker cores. Gradients emitted close sunset characterized titration O 3 reduced or no gradient formation. We show how lead underestimated emission overestimated products. These observations will improved predictions wildfire emissions, evolution, across daytime nighttime.

Language: Английский

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Emission factors for polycyclic aromatic hydrocarbons from laboratory biomass-burning and their chemical transformations during aging in an oxidation flow reactor

The Science of The Total Environment, Journal Year: 2023, Volume and Issue: 870, P. 161857 - 161857

Published: Jan. 30, 2023

Atmospheric polycyclic aromatic hydrocarbons (PAHs) can be emitted from different combustion sources including domestic biomass burning, internal engines, and burning (BB) in wild, prescribed, agricultural fires. With climate warming consequent global increases frequency severity of wildfires, BB is a dominant source PAHs into the atmosphere. In this study, six globally regionally important representative fuels (Alaskan peat, Moscow Pskov eucalyptus, Malaysian peat) were burned under controlled conditions chamber facility at Desert Research Institute (DRI, Reno, NV, USA). Gas- particle-phase emissions aged an oxidation flow reactor (OFR) to mimic five seven days atmospheric aging. To sample gas- emissions, fresh OFR-aged biomass-burning aerosols collected on Teflon-impregnated glass fiber filters (TIGF) tandem with XAD resin media for organic carbon speciation. The objectives study i) quantify emission factors 113 selected fuels, ii) characterize distribution PAH compounds between gas particle phases these iii) identify changes during OFR-aging, iv) evaluate toxicity potential characterized compounds. We found that gas-phase more abundant (>80 % by mass) than PAHs, all combusted fuels. mass fraction substituted napthalenes peat ∼70 & 84 %, respectively, whereas Eucalyptus same was <50 which indicates used as tracers emissions. Mass concentrations reduced after OFR oxidation. However, understanding fate requires further investigations. Our results also indicate samples would underestimated 10–100 times if only BaPeq 16 US EPA priority phase are included.

Language: Английский

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Ultraviolet Irradiation Can Increase the Light Absorption and Viscosity of Primary Brown Carbon from Biomass Burning

ACS Earth and Space Chemistry, Journal Year: 2023, Volume and Issue: 7(10), P. 1882 - 1889

Published: Oct. 9, 2023

The light absorption of brown carbon (BrC) constituents biomass burning organic aerosol (BBOA) changes in the atmosphere, part due to multiphase oxidation. For example, ozonolysis leads whitening primary BrC constituents. Irradiation can also change properties BrC. Here, we investigate interplay between irradiation and processing by measuring reactive uptake ozone thin films BBOA before after exposure UV radiation a photoreactor. Thin were prepared from lower volatility fraction eastern red cedar, species associated with wildfires prescribed fires southern Great Plains, United States. increased mass coefficient at near-UV visible wavelengths. It significantly decreased ozone, which was attributed viscosity material. These absorptivity are consistent results spectrometry tandem differential mobility analysis, show that high-molecular-weight constitute greater total irradiation. Our may have significant implications on warming effect BrC, since here both darkens this material makes it more resistant under conditions investigated.

Language: Английский

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Impact of the Atmospheric Photochemical Evolution of the Organic Component of Biomass Burning Aerosol on Its Radiative Forcing Efficiency: A Box Model Analysis

Atmosphere, Journal Year: 2021, Volume and Issue: 12(12), P. 1555 - 1555

Published: Nov. 24, 2021

We present the first box model simulation results aimed at identification of possible effects atmospheric photochemical evolution organic component biomass burning (BB) aerosol on radiative forcing (ARF) and its efficiency (ARFE). The simulations dynamics optical characteristics (OA) were performed using a simple parameterization developed within volatility basis set framework adapted to simulate multiday BB in idealized isolated smoke plumes from Siberian fires (without dilution). Our indicate that depth can be used as good proxy for studying effect OA ARF, but variations scattering absorbing properties also affect effects, evidenced by ARFE. Changes single albedo (SSA) asymmetry factor, which occur result evolution, may either reduce or enhance ARFE their competing depending initial concentration OA, ratio black carbon mass concentrations age complex way. reveal (1) top atmosphere is not significantly affected oxidation processes compared bottom atmosphere, (2) dependence column ages almost mirrors corresponding SSA.

Language: Английский

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Impacts of a Prescribed Fire on Air Quality in Central New Mexico

Atmosphere, Journal Year: 2023, Volume and Issue: 14(2), P. 316 - 316

Published: Feb. 5, 2023

A short-duration but high-impact air quality event occurred on 28 November 2018 along the Rio Grande Valley of New Mexico. This fire outside typical wildfire season, and greatly impacted in Socorro, NM, surroundings. Measurements were taken during using an aerosol light scattering technique (integrating nephelometer) a particulate mass concentration monitor (DustTrak PM optical monitor). The instruments sampled ambient campus Mexico Institute Mining Technology peak values 5-min basis reached 470 Mm−1 270 µg/m3, respectively. We examined meteorological context local data back trajectories NOAA HYSPLIT model to determine atmospheric transport possible sources. Several fires, both prescribed wildfires, region including burn at Bosque del Apache National Wildlife Refuge (17 km south-southeast receptor site). suggest that was dominant contributor due evidence event’s narrow spatiotemporal extent. increasing importance restoring ecosystem function wildland management will likely lead more frequent impacts sets up policy tradeoffs require balance between these public goals. study examines effects protected area impacting nearby populated area.

Language: Английский

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