Nighttime Chemical Transformation in Biomass Burning Plumes: A Box Model Analysis Initialized with Aircraft Observations

Abstract

Biomass burning (BB) is a large source of reactive compounds in the atmosphere. While the daytime photochemistry of BB emissions has been studied in some detail, there has been little focus on nighttime reactions despite the potential for substantial oxidative and heterogeneous chemistry. Here, we present the first analysis of nighttime aircraft intercepts of agricultural BB plumes using observations from the NOAA WP-3D aircraft during the 2013 Southeast Nexus (SENEX) campaign. We use these observations in conjunction with detailed chemical box modeling to investigate the formation and fate of oxidants (NO 3 , N 2 O 5 , O 3 , and OH) and BB volatile organic compounds (BBVOCs), using emissions representative of agricultural burns (rice straw) and western wildfires (ponderosa pine). Field observations suggest NO 3 production was approximately 1 ppbv hr −1 , while NO 3 and N 2 O 5 were at or below 3 pptv, indicating rapid NO 3 /N 2 O 5 reactivity. Model analysis shows that >99% of NO 3 / N 2 O 5 loss is due to BBVOC + NO 3 reactions rather than aerosol uptake of N 2 O 5. Nighttime BBVOC oxidation for rice straw and ponderosa pine fires is dominated by NO 3 (72, 53%, respectively) but O 3 oxidation is significant (25, 43%), leading to roughly 55% overnight depletion of the most reactive BBVOCs and NO 2 .

Comprehensive organic emission profiles, secondary organic aerosol production potential, and OH reactivity of domestic fuel combustion in Delhi, India

“…15 As a result, I/SVOCs from domestic solid fuel combustion potentially represent a large global source of SOA, however, the effect of I/SVOCs on OH reactivity, aging and SOA formation remains poorly understood. [16][17][18] The factors controlling SOA formation are complex. These include the oxidation of NMVOCs to less volatile products which partition into the particle phase, the heterogeneous oxidation of particle-phase SVOCs, and plume dilution with subsequent SVOC evaporation followed by further gas-phase oxidation.…”

Molecular Absorption and Evolution Mechanisms of PM2.5Brown Carbon Revealed by Electrospray Ionization Fourier Transform–Ion Cyclotron Resonance Mass Spectrometry During a Severe Winter Pollution Episode in Xi'an, China

“…Secondary transformation of precursors was another source of ambient BrC. NO 3 , amines, and ammonium sulfate‐mediated transformation produces strong light‐absorbing BrC (Decker et al, 2019; Jiang et al, 2019; Powelson et al, 2013). Secondary BrC formed by direct photolysis and OH oxidation is photobleaching (Zhao, Lee, et al, 2015).…”

Emissions of intermediate-volatility and semi-volatile organic compounds from domestic fuels used in Delhi, India

“…Large emissions of furanic species were measured from fuel wood (6-59 %), municipal solid waste (35-45 %), cow dung cake (39-42 %), crop residue (25-44 %) and sawdust (43 %). These were important as furans can be toxic and mutagenic (Ravindranath et al, 1984;Peterson, 2006;Monien et al, 2011;WHO, 2016) and have been shown to be some of the species with the highest OH reactivity from biomass burning emissions (Hartikainen et al, 2018;Coggon et al, 2019). Furans have also been shown to result in SOA production (Gómez Alvarez et al, 2009;Strollo and Ziemann, 2013) with 8-15 % of SOA produced from combustion of black spruce, cut grass, Indonesian peat and ponderosa pine estimated to originate from furans and 28-50 % of SOA from rice straw and wiregrass (Hatch et al, 2015).…”

“…However, the effect of atmospheric of aging on I/SVOCs still remains poorly understood (Liu et al, 2017;Decker et al, 2019;Sengupta et al, 2020).…”