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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Composition and mixing state of Arctic aerosol and cloud residual particles from long-term single-particle observations at Zeppelin Observatory, Svalbard

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(21), P. 14421 - 14439

Published: Nov. 10, 2022

Abstract. The Arctic region is sensitive to climate change and warming faster than the global average. Aerosol particles cloud properties by acting as condensation nuclei ice-nucleating particles, thus influencing system. Therefore, understanding aerosol particle in needed interpret simulate their influences on climate. In this study, we collected ambient using whole-air PM10 inlets residual of droplets ice crystals from low-level clouds (typically, all-liquid or mixed-phase clouds) a counterflow virtual impactor inlet at Zeppelin Observatory near Ny-Ålesund, Svalbard, within time frame 4 years. We measured composition mixing state individual fine-mode 239 samples transmission electron microscopy. On basis composition, were classified mineral dust, sea salt, K-bearing, sulfate, carbonaceous particles. number fraction showed seasonal changes, with sulfate dominating summer salt increasing winter. There was no measurable difference fractions between temperatures above 0 ∘C. other hand, below ∘C had several times more dust fewer sulfates samples, suggesting that spray may influence formation clouds. also found 43 % mixed whereas only 18 salt. This study highlights variety compositions states are influenced aerosol–cloud interactions

Language: Английский

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Emission factors and evolution of SO₂ measured from biomass burning in wildfires and agricultural fires

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(23), P. 15603 - 15620

Published: Dec. 13, 2022

Abstract. Fires emit sufficient sulfur to affect local and regional air quality climate. This study analyzes SO2 emission factors variability in smoke plumes from US wildfires agricultural fires, as well their relationship sulfate hydroxymethanesulfonate (HMS) formation. Observed for various fuel types show good agreement with the latest reviews of biomass burning factors, producing an factor range 0.47–1.2 g kg−1 C. These vary geographic location a way that suggests deposition coal emissions application sulfur-containing fertilizers likely play role larger observed values, which are primarily associated burning. A 0-D box model generally reproduces trends total (inorganic + organic) aging wildfire plumes. In many cases, modeled HMS is consistent organosulfur concentrations. However, comparison multiple compounds responsible observations but chemistry these yields similar production loss rates HMS, resulting results. We provide suggestions constraining during flights, we can allow act S(IV) reservoir under conditions pH > 6 liquid water content >10−7 sm−3. facilitate long-range transport emissions, increased eventually transported smoke.

Language: Английский

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Look Within: Intraplume Differences on Smoke Aerosol Aging Driven by Concentration Gradients

Journal of Geophysical Research Atmospheres, Journal Year: 2025, Volume and Issue: 130(5)

Published: Feb. 26, 2025

Abstract The evolution of organic aerosol (OA) composition and size distributions within smoke plumes are uncertain due to variability in the rates OA evaporation/condensation coagulation a plume. It remains unclear how varies across different parts individual plumes. We use large eddy simulation model coupled with aerosol‐microphysics radiation models simulate Williams Flats fire sampled during Fire Influence on Regional Global Environments Air Quality field campaign. At aircraft altitude, captures observed changes through 4 hr aging. primary (POA), oxidized POA (OPOA), secondary (SOA) shows that >90% SOA formation occurs before first transect (∼40 min aging). Lidar observations show significant amount planetary boundary layer (PBL) free troposphere (FT) having equal amounts PBL FT. Due faster initial dilution, concentrations more than factor two lower FT concentrations, resulting slower coagulational growth PBL. A 20 K temperature decrease height influences evaporation near surface, while net is driven by continued dilution after transect. Net condensation result areas higher OH concentration leading OPOA formation. Our results motivate need for systematic vertical gradients

Language: Английский

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Direct Measurements and Implications of the Aerosol Asymmetry Parameter in Wildfire Smoke During FIREX‐AQ

Journal of Geophysical Research Atmospheres, Journal Year: 2025, Volume and Issue: 130(6)

Published: March 26, 2025

Abstract We present direct measurements of the asymmetry parameter ( g ) from biomass burning aerosol at two wavelengths using Laser Imaging Nephelometer. compare with Mie theory calculations based on optically measured size distributions and values derived hemispheric backscatter b both an integrating imaging nephelometer. During FIREX‐AQ field mission, we optical microphysical properties smoke plumes that had been emitted between 0.5 8.5 hr earlier. find can only be reproduced particle distribution a higher refractive index than is typically retrieved remote assumed in some models. Retrievals performed GRASP algorithm suggest wavelength‐dependent n = 1.55 ± 0.03 λ 660 nm (1.63 0.04) 405 nm. Using simple radiative transfer equation, show instantaneous cooling planet by fresh increased 20% when evaluated instead assuming 1.52. Besides improving model representations smoke, more accurate improve retrievals sensing techniques. Better will provide constraint emissions inventories used global regional This ultimately reduce uncertainty forcing associated increasing frequency magnitude wildfires.

Language: Английский

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Physicochemical properties of charcoal aerosols derived from biomass pyrolysis affect their ice-nucleating abilities at cirrus and mixed-phase cloud conditions

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(2), P. 1285 - 1308

Published: Jan. 24, 2023

Abstract. Atmospheric aerosol particles play a key role in air pollution, health, and climate. Particles from biomass burning emissions are an important source of ambient aerosols, have increased over the past few decades, projected to further surge future as result climate land use changes. Largely variety organic fuel materials combustion types, emitted often complex mixtures inorganic materials, with soot, ash, charcoal having previously been identified main particle types being emitted. Despite their importance for climate, ice nucleation activities remain insufficiently understood, particular particles, whose activity has not reported. Here, we present experiments 400 nm size-selected derived pyrolysis two different fuels, namely grass wood charcoal. We find that pyrolysis-derived investigated do contribute formation via immersion freezing mixed-phase cloud conditions. However, our results reveal considerable heterogeneous both at cirrus temperatures. An inspection together dynamic vapor sorption measurements indicates proceeds pore condensation freezing. be more ice-active than attribute this enhanced porosity water uptake capacity compared In support results, found positive correlation chemical composition, specifically presence (inorganic) mineral components, based on single-particle mass spectrometry measurements. Even though correlational nature, corroborate recent findings minerals could largely govern aerosol–cloud interactions emissions.

Language: Английский

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Sea salt reactivity over the northwest Atlantic: an in-depth look using the airborne ACTIVATE dataset

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(5), P. 3349 - 3378

Published: March 18, 2024

Abstract. Chloride (Cl−) displacement from sea salt particles is an extensively studied phenomenon with implications for human health, visibility, and the global radiation budget. Past works have investigated Cl− depletion over northwest Atlantic (NWA); however, updated, multi-seasonal, geographically expanded account of reactivity region needed. This study uses chemically resolved mass concentrations meteorological data airborne Aerosol Cloud meTeorology Interactions oVer western ATlantic Experiment (ACTIVATE) to quantify seasonal, spatial, trends in explore importance quantifying (1) non-sea sources Na+ (2) lost (instead relative amounts displaced). Lost are lowest December–February March, moderate around Bermuda June, highest May (median losses 0.04, 0.66, 1.76 µg m−3, respectively), that high enough potentially accelerate tropospheric oxidation rates. Inorganic acidic species can all December–February, June near but none May, suggesting organic acids may be certain months. Contributions dust not important seasonally cause relevant overestimates smoke plumes. Higher percentages often do correspond larger Cl−, so it highly recommended latter place reactions context their role atmospheric radiative forcing.

Language: Английский

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Occurrence, abundance, and formation of atmospheric tarballs from a wide range of wildfires in the western US

Published: April 15, 2024

Abstract. Biomass burning emits large numbers of organic aerosol particles, a subset which are called tarballs (TBs). TBs possess spherical morphology and unique physical, chemical, optical properties. They recognized as brown carbon thereby having implications for climate through the absorption solar radiation. Aerosol particles were collected from wildfire agricultural fire smoke sampled by NASA DC-8 aircraft during FIREX-AQ campaign in western US July to September 2019. The current study developed an image analysis method applying deep learning distinguish other round that deformed on substrate, based their morphological characteristics transmission electron microscopy images. This detected 4567 with mostly <10 h downwind emissions measured compositions, abundance, sizes, mixing states. number fraction, mass concentration all 10 % ± 1 %, 2 10.1 4.6 µg m-3, respectively. As samples aged emission up 5 h, TB fractions roughly increased 15 indicating processed primary particles. In more samples, fraction decreased possibly due dilution removal. We also showed within pyrocumulonimbus (PyroCb) activity various reveals abundances physical chemical properties wide range biomass-burning events enhances knowledge emissions, contributes evaluation impact TBs.

Language: Английский

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Wildfire smoke impacts lake ecosystems

Global Change Biology, Journal Year: 2024, Volume and Issue: 30(6)

Published: June 1, 2024

Abstract Wildfire activity is increasing globally. The resulting smoke plumes can travel hundreds to thousands of kilometers, reflecting or scattering sunlight and depositing particles within ecosystems. Several key physical, chemical, biological processes in lakes are controlled by factors affected smoke. spatial temporal scales lake exposure extensive under‐recognized. We introduce the concept smoke‐day, number days any given exposed fire season, quantify total smoke‐day North America from 2019 2021. Because be transported at continental intercontinental scales, even regions that may not typically experience direct burning landscapes wildfire risk exposure. found 99.3% was covered smoke, affecting a 1,333,687 ≥10 ha. An incredible 98.9% experienced least 10 smoke‐days year, with 89.6% receiving over 30 smoke‐days, some experiencing up 4 months cumulative smoke‐days. Herein we review mechanisms through which ash affect altering amount spectral composition incoming solar radiation carbon, nutrients, toxic compounds could alter chemical conditions impact biota. develop conceptual framework synthesizes known theoretical impacts on guide future research. Finally, identify emerging research priorities help us better understand how will as increases due climate change other anthropogenic activities.

Language: Английский

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Occurrence, abundance, and formation of atmospheric tarballs from a wide range of wildfires in the western US

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(19), P. 10985 - 11004

Published: Oct. 1, 2024

Abstract. Biomass burning emits large numbers of organic aerosol particles, a subset which are called tarballs (TBs). TBs possess spherical morphology and unique physical, chemical, optical properties. They recognized as brown-carbon influencing the climate through absorption solar radiation. Aerosol particles were collected from wildfire agricultural-fire smoke sampled by NASA's DC-8 aircraft during Fire Influence on Regional to Global Environments Air Quality (FIREX-AQ) campaign in western US July September 2019. This study developed an image analysis method using deep learning distinguish other round that deformed substrate, based particles' morphological characteristics transmission electron microscopy images. detected 4567 TBs, with most occurring < 10 h downwind emissions, measured their compositions, abundance, sizes, mixing states. The number fraction, mass concentration corresponded ± 1 %, 2 10.1 4.6 µg m−3, respectively. As aged for up 5 after emission, TB fractions roughly increased % 15 indicating processed primary particles. We also observed associated pyrocumulonimbus (pyroCb) activity various reveals well physical chemical properties, wide range biomass-burning events enhances our knowledge contributing evaluation impact TBs.

Language: Английский

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