Contribution of Carbonyl Chromophores in Secondary Brown Carbon from Nighttime Oxidation of Unsaturated Heterocyclic Volatile Organic Compounds DOI Creative Commons
Kunpeng Chen, Raphael Mayorga, Caitlin Hamilton

et al.

Environmental Science & Technology, Journal Year: 2023, Volume and Issue: 57(48), P. 20085 - 20096

Published: Nov. 20, 2023

The light absorption properties of brown carbon (BrC), which are linked to molecular chromophores, may play a significant role in the Earth's energy budget. While nitroaromatic compounds have been identified as strong chromophores wildfire-driven BrC, other types remain be investigated. Given electron-withdrawing nature carbonyls ubiquitous atmosphere, we characterized carbonyl BrC samples from nighttime oxidation furan and pyrrole derivatives, important but understudied precursors secondary organic aerosols primarily found wildfire emissions. Various were quantified samples, their ultraviolet-visible spectra simulated by using time-dependent density functional theory. Our findings suggest that with bonded nitrogen (i.e., imides amides) derived N-containing heterocyclic substantially contribute absorption. contributed over 40% total at wavelengths below 350 nm above 430 BrC. contributions differed significantly wavelength, highlighting divergent importance different wavelength ranges. Overall, our highlight significance underscore need for further investigation.

Language: Английский

Relative Humidity Modulates the Physicochemical Processing of Secondary Brown Carbon Formation from Nighttime Oxidation of Furan and Pyrrole DOI Creative Commons
Kunpeng Chen, Caitlin Hamilton,

B. Ries

et al.

ACS ES&T Air, Journal Year: 2024, Volume and Issue: 1(5), P. 426 - 437

Published: April 9, 2024

Light-absorbing secondary organic aerosols (SOAs), also known as brown carbon (BrC), are major components of wildfire smoke that can have a significant impact on the climate system; however, how environmental factors such relative humidity (RH) influence their formation is not fully understood, especially for heterocyclic precursors. We conducted chamber experiments to investigate BrC from nighttime oxidation furan and pyrrole, two primary precursors in wildfires, presence pre-existing particles at RH < 20% ∼ 50%. Our findings revealed increasing significantly affected size distribution dynamics both SOAs, with pyrrole SOA showing stronger potential generate ultrafine via intensive nucleation processes. Higher led increased mass fractions oxygenated compounds suggesting enhanced gas-phase and/or multiphase under humid conditions. Moreover, higher reduced absorption coefficients BrC, contrasting those homocyclic precursors, due non-absorbing high-molecular-weight decreasing molecular chromophores. Overall, our demonstrate unique dependence which may critically modulate radiative effects change.

Language: Английский

Citations

6
Interannual variability of summertime formaldehyde (HCHO) vertical column density and its main drivers at northern high latitudes DOI Creative Commons

Tianlang Zhao,

Jingqiu Mao, Zolal Ayazpour

et al.

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(10), P. 6105 - 6121

Published: May 28, 2024

Abstract. The northern high latitudes (50–90° N, mostly including boreal-forest and tundra ecosystems) have been undergoing rapid climate ecological changes over recent decades, leading to significant variations in volatile organic compounds (VOC) emissions from biogenic biomass burning sources. Formaldehyde (HCHO) is an indicator of VOC emissions, but the interannual variability HCHO its main drivers region remains unclear. In this study, we use GEOS-Chem chemical transport model satellite retrievals Ozone Monitoring Instrument (OMI) Mapping Profiler Suite (OMPS) examine vertical column density (VCD) during summer seasons spanning 2005 2019. Our results show that, 2005–2019 summers, wildfires contributed 75 %–90 % VCD Siberia, Alaska Canada, while background methane oxidation account for ∼ 90 eastern Europe. We find that monthly solar-induced chlorophyll fluorescence (SIF) Orbiting Carbon Observatory-2 (OCO-2), efficient proxy plant photosynthesis, shows a good linear relationship (R= 0.6–0.7) with modeled (dVCDBio,GC) Europe, indicating coupling between SIF four domains on scale. Alaska, Siberia dVCDBio,GC both relatively lower variabilities (SIF: CV = 1 %–9 %, dVCDBio,GC: %–2 %; note stands coefficient variation) comparison wildfire-induced (CV 8 %–13 %), suggesting OMI 10 %–16 %) these are likely driven by instead emissions.

Language: Английский

Citations

6
Intense formation of secondary ultrafine particles from Amazonian vegetation fires and their invigoration of deep clouds and precipitation DOI Creative Commons
Manish Shrivastava, Jiwen Fan, Yuwei Zhang

et al.

One Earth, Journal Year: 2024, Volume and Issue: 7(6), P. 1029 - 1043

Published: June 1, 2024

New particle formation (NPF) in fire smoke is thought to be unlikely due large condensation and coagulation sinks that scavenge molecular clusters. We analyze aircraft measurements over the Amazon find fires significantly enhance NPF ultrafine (UFP < 50 nm diameter) numbers compared background conditions, contrary previous understanding. identify nucleation of dimethylamine with sulfuric acid, which aided by extremely low volatility organics biomass-burning smoke, can overcome explain observations. show freshly formed clusters rapidly grow UFP sizes through secondary organic aerosol formation, leading a 10-fold increase number concentrations. contrasting effect UFPs on deep convective clouds larger particles from primary emissions for case investigated here. intensify precipitation increased condensational heating, while delay reduce precipitation.

Language: Английский

Citations

6
Carbon Monoxide in Optically Thick Wildfire Smoke: Evaluating TROPOMI Using CU Airborne SOF Column Observations DOI
Jake P. Rowe, Kyle J. Zarzana, Natalie Kille

et al.

ACS Earth and Space Chemistry, Journal Year: 2022, Volume and Issue: 6(7), P. 1799 - 1812

Published: June 16, 2022

TROPOspheric Monitoring Instrument (TROPOMI) measurements of carbon monoxide (CO) vertical column enhancements in optically thick biomass burning plumes were evaluated using from the University Colorado Airborne Solar Occultation Flux (CU AirSOF) instrument during 2018 Biomass Burning Fluxes Trace Gases and Aerosols (BB-FLUX) field campaign northwestern United States. The different temporal spatial scales measurement geometries sampled aircraft satellite are actively accounted for by (1) focusing on coincident measurements, (2) comparing integrals CO across plume transects, (3) FLEXible PARTicle (FLEXPART) dispersion model to correct atmospheric transport, (4) accounting Averaging Kernels (AVK). TROPOMI is found be systematically higher relative +36% operational product (+27% preoperational product) without geospatial corrections. Consecutive transects CU AirSOF revealed significant variations between integrated (on average 28% over 30 min) sub-pixel scale. When additional corrections applied (FLEXPART, a lesser degree also AVK), bias reduced +10% (+7.2% preoperational), which insignificant within 15% uncertainty (variability among case studies, 95% confidence level). Radiative transfer simulations synthetic indicate that multiple scattering can enhance signals 5–10% at high aerosol loads, warrants further attention. Smoke strongly reduces trace gas ultraviolet visible wavelengths (by up factor 6), highlighting importance multispectral properties smoke.

Language: Английский

Citations

25
Contribution of Carbonyl Chromophores in Secondary Brown Carbon from Nighttime Oxidation of Unsaturated Heterocyclic Volatile Organic Compounds DOI Creative Commons
Kunpeng Chen, Raphael Mayorga, Caitlin Hamilton

et al.

Environmental Science & Technology, Journal Year: 2023, Volume and Issue: 57(48), P. 20085 - 20096

Published: Nov. 20, 2023

The light absorption properties of brown carbon (BrC), which are linked to molecular chromophores, may play a significant role in the Earth's energy budget. While nitroaromatic compounds have been identified as strong chromophores wildfire-driven BrC, other types remain be investigated. Given electron-withdrawing nature carbonyls ubiquitous atmosphere, we characterized carbonyl BrC samples from nighttime oxidation furan and pyrrole derivatives, important but understudied precursors secondary organic aerosols primarily found wildfire emissions. Various were quantified samples, their ultraviolet-visible spectra simulated by using time-dependent density functional theory. Our findings suggest that with bonded nitrogen (i.e., imides amides) derived N-containing heterocyclic substantially contribute absorption. contributed over 40% total at wavelengths below 350 nm above 430 BrC. contributions differed significantly wavelength, highlighting divergent importance different wavelength ranges. Overall, our highlight significance underscore need for further investigation.

Language: Английский

Citations

16