Comment on acp-2022-167 DOI Creative Commons

D.A.J. Jaffe

Published: Feb. 1, 2023

Abstract. We characterize the aerosol physical and optical properties of 13 transported biomass burning (BB) events. BB events included long-range influence from fires in Alaskan Siberian boreal forests to Mt. Bachelor Observatory (MBO) free troposphere (FT) over 8–14+ d regional wildfires northern California southwestern Oregon MBO boundary layer (BL) 10 h 3 d. Intensive normalized enhancement ratios for were derived measured light scattering coefficients (σscat), light-absorbing class="inline-formula">σabs), fine particulate matter (PM1), carbon monoxide (CO) measurements made July September 2019, with particle size distribution collected August September. The observations showed that had a lower à ngström exponent (SAE), higher mass efficiency (MSE; Δσscat/PM1), bimodal geometric mean diameter class="inline-formula">Dg). hypothesize larger particles associated due transport dust alongside smoke addition contributions condensation secondary aerosol, coagulation smaller particles, aqueous-phase processing during transport. forest plumes long distances the FT characterized by absorption (AAE) values indicative black carbon (BC) dominance radiative budget. Significantly elevated AAE only observed class="inline-formula"><1 d transport, which suggests strong production brown (BrC) these but limited forcing impacts outside immediate region.

Language: Английский

Using the Black Carbon Particle Mixing State to Characterize the Lifecycle of Biomass Burning Aerosols DOI
Arthur J. Sedlacek, Ernie R. Lewis, T. B. Onasch

et al.

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

Citations

58
Chemical and Light-Absorption Properties of Water-Soluble Organic Aerosols in Northern California and Photooxidant Production by Brown Carbon Components DOI Creative Commons
Wenqing Jiang, Lan Ma, Christopher Niedek

et al.

ACS Earth and Space Chemistry, Journal Year: 2023, Volume and Issue: 7(5), P. 1107 - 1119

Published: April 24, 2023

Atmospheric brown carbon (BrC) can impact the radiative balance of earth and form photooxidants. However, light absorption photochemical properties BrC from different sources remain poorly understood. To address this gap, dilute water extracts particulate matter (PM) samples collected at Davis, CA over one year were analyzed using high resolution aerosol mass spectrometry (HR-AMS) UV-vis spectroscopy. Positive matrix factorization (PMF) on combined AMS data resolved five water-soluble organic (WSOA) factors with distinct spectra spectra: a fresh an aged biomass burning OA (WSBBOAfresh WSBBOAaged) three oxygenated (WSOOAs). WSBBOAfresh is most light-absorbing, coefficient (MAC365 nm) 1.1 m2 g-1, while WSOOAs are least nm = 0.01-0.1 g-1). These results, together abundance WSBBOAs (∼52% WSOA mass), indicate that activities such as residential wood wildfires important source in northern California. The concentrations aqueous-phase photooxidants, i.e., hydroxyl radical (·OH), singlet molecular oxygen (1O2*), oxidizing triplet excited states (3C*), also measured PM during illumination. Oxidant production potentials (PPOX) explored. photoexcitation chromophores BB emissions OOAs significant 1O2* 3C*. By applying our PPOX values to archived dozens sites, we found species play role photooxidant formation atmospheric waters.

Language: Английский

Citations

27
Seasonal variations in photooxidant formation and light absorption in aqueous extracts of ambient particles DOI Creative Commons
Lan Ma,

Reed Worland,

Laura Marie Dahler Heinlein

et al.

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(1), P. 1 - 21

Published: Jan. 2, 2024

Abstract. Fog/cloud drops and aerosol liquid water are important sites for the transformations of atmospheric species, largely through reactions with photoformed oxidants such as hydroxyl radical (⚫OH), singlet molecular oxygen (1O2∗), oxidizing triplet excited states organic matter (3C∗). Despite their importance, few studies have measured these or seasonal variations. To address this gap, we collected ambient PM2.5 from Davis, California, over course a year photooxidant concentrations light absorption in dilute aqueous extracts. Mass coefficients (MACs) normalized by dissolved carbon range 0.4–3.8 m2 per gram C at 300 nm. Concentrations ⚫OH, 1O2∗, 3C∗ extracts (0.2–4.7) × 10−15 M, (0.7–45) 10−13 (0.03–7.9) respectively, biomass burning brown playing major role formation 1O2∗ 3C∗. Extrapolating kinetics our particle to concentrated (ALW) conditions gives an estimated ⚫OH concentration 7 M ranges (0.6–7) 10−12 (0.2–1) respectively. Compared results Kaur et al. (2019), ALW predictions show roughly 10 times higher up 5 3C, that lower factors 20–100. These suggest dominate processing compounds react quickly (e.g., phenols furans, respectively), while is more less reactive organics.

Language: Английский

Citations

7
Mass spectrometric analysis of unprecedented high levels of carbonaceous aerosol particles long-range transported from wildfires in the Siberian Arctic DOI Creative Commons
Eric Schneider, Hendryk Czech, Olga Popovicheva

et al.

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(1), P. 553 - 576

Published: Jan. 15, 2024

Abstract. Wildfires in Siberia generate large amounts of aerosols, which may be transported over long distances and pose a threat to the sensitive ecosystem Arctic. Particulate matter (PM) aged wildfire plumes originating from Yakutia August 2021 was collected Nadym on Bely Island (both northwestern Siberia). An advanced analysis chemical composition aerosol particles conducted through multi-wavelength thermal–optical carbon analyzer (TOCA) coupled resonance-enhanced multiphoton ionization time-of-flight mass spectrometry (REMPI-TOFMS) as well ultra-high-resolution Fourier-transform ion cyclotron resonance (FT-ICR MS). In Nadym, concentrations organic (OC) elemental (EC) peaked at 100 40 µg m−3, respectively, associated with Angström absorption exponents for 405 808 nm (AAE405/808) between 1.5 3.3. The weekly average 8.9 m−3 OC 0.3 EC AAE405/808 close unity. particular, ambient had distinct biomass burning profile pyrolysis products carbohydrates, such cellulose hemicellulose, lignin resinoic acids. However, temporarily higher five- six-ring polycyclic aromatic hydrocarbons (PAHs), different PAH signature burning, suggest contribution regional gas flaring. FT-ICR MS electrospray (ESI) revealed complex mixture highly functionalized compounds, containing up 20 oxygen atoms, nitrogen- sulfur-containing moieties. Concentrations markers were substantially lower than flanked by appearance unique compounds content, molecular weight, aromaticity. Back-trajectory satellite-derived optical depth suggested long-range transport center Yakutian plume periphery Island. Owing its center, it is demonstrated how dilution affects during atmospheric aging.

Language: Английский

Citations

6
Molecular insight into biomass-burning smoke water-soluble organic matter binding with Cd(II): Comprehensive analysis from fluorescence EEM-PARAFAC, FT-ICR-MS and two-dimensional correlation spectroscopy DOI
Weifeng Chen, Cheng Yue, Huiying Zhang

et al.

Journal of Hazardous Materials, Journal Year: 2024, Volume and Issue: 479, P. 135754 - 135754

Published: Sept. 4, 2024

Language: Английский

Citations

5
Optical properties of biomass burning aerosol during the 2021 Oregon fire season: comparison between wild and prescribed fires DOI Creative Commons
Andrey Marsavin,

Ralph van Gageldonk,

Noah Bernays

et al.

Environmental Science Atmospheres, Journal Year: 2023, Volume and Issue: 3(3), P. 608 - 626

Published: Jan. 1, 2023

The Mt. Bachelor Observatory was frequently impacted by biomass burning smoke in 2021, an extreme forest fire year the state of Oregon.

Language: Английский

Citations

11
Molecular Insights into Gas–Particle Partitioning and Viscosity of Atmospheric Brown Carbon DOI
Qiaorong Xie, Nealan G. A. Gerrebos, Diego Calderon‐Arrieta

et al.

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 4, 2024

Biomass burning organic aerosol (BBOA), containing brown carbon chromophores, plays a critical role in atmospheric chemistry and climate forcing. However, the effects of evaporation on BBOA volatility viscosity under different environmental conditions remain poorly understood. This study focuses molecular characterization laboratory-generated proxies from wood pyrolysis emissions. The initial mixture, "pyrolysis oil (PO

Language: Английский

Citations

4
Evaluating the Effects of Biomass Burning on Severe Haze Formation in a Megacity of Sichuan Basin, Southwestern China DOI Creative Commons

Zhier Bao,

Yiliang Liu, Lingshuo Meng

et al.

Journal of Geophysical Research Atmospheres, Journal Year: 2025, Volume and Issue: 130(2)

Published: Jan. 17, 2025

Abstract Severe haze pollution has long been an environmental problem, which is complicated and poorly understood in the Sichuan Basin (SCB). In this study, a field observation was carried out to investigate factors driving formation urban Chengdu, typical megacity SCB. It found that accumulation of biomass burning organic aerosol (BBOA) played important role Chengdu. The average mass fraction BBOA PM 2.5 increased from ∼1% during clear days ∼10% severe episodes. A method combining backward trajectory analysis with fire spot distribution used evaluate effects regional transport (BB) emissions. results showed concentration by ∼3 times ∼54% when BB emissions were transported adjacent areas Moreover, parameter f 60 (the ratio integrated signal at m/z total component spectrum), indicated impacts emissions, reassessed be 0.54% instead widely value 0.3% previously. Our uncovered importance on SCB provided new insights into pollutant mitigation strategies region.

Language: Английский

Citations

0
An attribution of the low single-scattering albedo of biomass burning aerosol over the southeastern Atlantic DOI Creative Commons
Amie Dobracki, Paquita Zuidema, S. G. Howell

et al.

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(8), P. 4775 - 4799

Published: April 24, 2023

Abstract. Aerosol over the remote southeastern Atlantic is some of most sunlight-absorbing aerosol on planet: in situ free-tropospheric single-scattering albedo at 530 nm wavelength (SSA530 nm) ranges from 0.83 to 0.89 within ORACLES (ObseRvations Aerosols above CLouds and their intEractionS) aircraft flights late August–September. Here we seek explain low SSA. The SSA depends strongly black carbon (BC) number fraction, which 0.15 0.4. Low organic (OA)-to-BC mass ratios 8–14 modified combustion efficiency values >0.975 point indirectly dry, flame-efficient primarily grass fuels, with back trajectories ending miombo woodlands Angola. youngest aerosol, aged 4–5 d since emission, occupied top half a 5 km thick plume sampled directly west Angola vertically consistent BC:ΔCO (carbon monoxide) ratio, indicating homogenization source emissions. younger transported more quickly off continent by stronger winds, overlaid older, slower-moving larger mean particle size fraction BC-containing particles. This ongoing gas condensation coagulation smaller non-BC particles upon volumes OA:BC older were smaller, attributed evaporation following fragmentation, instead dilution or thermodynamics. CLARIFY (CLoud–Aerosol–Radiation Interaction Forcing: Year 2017) campaign aerosols that had traveled further reach Ascension Island. reported higher BC fractions, lower ratios, yet absorption coefficients compared this study's. Values one 2017 flight, held midway Island, are intermediate, confirming long-range changes. Overall data continuing oxidation through fragmentation releasing subsequently enter phase, reducing OA mass, rather than support best fit: SSA530nm=0.801+0055⋅(OA:BC) (r=0.84). fires southern Africa emit approximately one-third world's carbon; emitted distinct other regional smoke emissions, composition needs be represented appropriately realistically depict radiative effects.

Language: Английский

Citations

10
Fingerprints of the COVID-19 economic downturn and recovery on ozone anomalies at high-elevation sites in North America and western Europe DOI Creative Commons
Davide Putero, Paolo Cristofanelli, Kai‐Lan Chang

et al.

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(24), P. 15693 - 15709

Published: Dec. 21, 2023

Abstract. With a few exceptions, most studies on tropospheric ozone (O3) variability during and following the COrona VIrus Disease (COVID-19) economic downturn focused high-emission regions or urban environments. In this work, we investigated impact of societal restriction measures COVID-19 pandemic surface O3 at several high-elevation sites across North America western Europe. Monthly anomalies were calculated for 2020 2021, with respect to baseline period 2000–2019, explore initiated in its recovery 2021. total, 41 analyzed: 5 rural mountaintop stations Europe, 19 US, 4 US downwind highly polluted source regions, eastern plus 9 outside Europe United States provide “global” reference. 2020, European showed persistent negative spring (March–May, i.e., MAM) summer (June–August, JJA), except April. The pattern was similar June. behavior, MAM JJA (except August) 2021 seasonal mean influenced by strong positive July due large widespread wildfires US. slight resulting anomaly pronounced month-to-month anomalies. also characterized below-mean both while values exhibited an opposite structure compared sites, which wildfires. Concerning rest world, global picture could not be drawn, as spanning range different environments, did show consistent anomalies, experiencing any notable variation. Moreover, our mid-tropospheric detected IASI (Infrared Atmospheric Sounding Interferometer) satellite instrument. Negative observed IASI, published modeling studies, suggesting that can largely attributed reduction precursor emissions 2020.

Language: Английский

Citations

10