Document


Title

Photochemical cloud processing of primary wildfire emissions as a potential source of secondary organic aerosol
Document Type: Journal Article
Author(s): Sophie Tomaz; Tianqu Cui; Yuzhi Chen; Kenneth G. Sexton; James M. Roberts; Carsten Warneke; Robert J. Yokelson; Jason D. Surratt; Barbara J. Turpin
Publication Year: 2018

Cataloging Information

Keyword(s):
  • biomass burning
  • organic aerosols
Record Maintained By:
Record Last Modified: August 8, 2019
FRAMES Record Number: 58411

Description

We investigated the gas-phase chemical composition of biomass burning (BB) emissions and their role in aqueous secondary organic aerosol (aqSOA) formation through photochemical cloud processing. A high-resolution time-of-flight chemical ionization mass spectrometer using iodide reagent ion chemistry detected more than 100 gas-phase compounds from the emissions of 30 different controlled burns during the 2016 Fire Influence on Regional and Global Environments Experiment (FIREX) at the Fire Science Laboratory. Compounds likely to partition to cloudwater were selected based on high atomic oxygen-to-carbon ratio and abundance. Water solubility was confirmed by detection of these compounds in water after mist chamber collection during controlled burns and analysis using ion chromatography and electrospray ionization interfaced to high-resolution time-of-flight mass spectrometry. Known precursors of aqSOA were found in the primary gaseous BB emissions (e.g., phenols, acetate, and pyruvate). Aqueous OH oxidation of the complex biomass burning mixtures led to rapid depletion of many compounds (e.g., catechol, levoglucosan, methoxyphenol) and formation of others (e.g., oxalate, malonate, mesoxalate). After 150 min of oxidation (approximatively 1 day of cloud processing), oxalate accounted for 13-16% of total dissolved organic carbon. Formation of known SOA components suggests that cloud processing of primary BB emissions forms SOA.

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Citation:
Tomaz, Sophie; Cui, Tianqu; Chen, Yuzhi; Sexton, Kenneth G.; Roberts, James M.; Warneke, Carsten; Yokelson, Robert J.; Surratt, Jason D.; Turpin, Barbara J. 2018. Photochemical cloud processing of primary wildfire emissions as a potential source of secondary organic aerosol. Environmental Science & Technology 52(19):11027-11037.