Atmospheric evolution of emissions from a boreal forest fire: the formation of highly functionalized oxygen-, nitrogen-, and sulfur-containing organic compounds

Abstract

Abstract. Forest fires are major contributors of reactive gas- and particle-phase organic compounds to the atmosphere. We used offline high-resolution tandem mass spectrometry to perform a molecular-level speciation of gas- and particle-phase compounds sampled via aircraft from an evolving boreal forest fire smoke plume in Saskatchewan, Canada. We observed diverse multifunctional compounds containing oxygen, nitrogen, and sulfur (CHONS), whose structures, formation, and impacts are understudied. The dilution-corrected absolute ion abundance of particle-phase CHONS compounds increased with plume age by a factor of 6.4 over the first 4 h of downwind transport, and their relative contribution to the observed functionalized organic aerosol (OA) mixture increased from 19 % to 40 %. The dilution-corrected absolute ion abundance of particle-phase compounds with sulfide functional groups increased by a factor of 13 with plume age, and their relative contribution to observed OA increased from 4 % to 40 %. Sulfides were present in up to 75 % of CHONS compounds and the increases in sulfides were accompanied by increases in ring-bound nitrogen; both increased together with CHONS prevalence. A complex mixture of intermediate- and semi-volatile gas-phase organic sulfur species was observed in emissions from the fire and depleted downwind, representing potential precursors to particle-phase CHONS compounds. These results demonstrate CHONS formation from nitrogen- and oxygen-containing biomass burning emissions in the presence of reduced sulfur species. In addition, they highlight chemical pathways that may also be relevant in situations with elevated emissions of nitrogen- and sulfur-containing organic compounds from residential biomass burning and fossil fuel use (e.g., coal), respectively.

Biomass burning nitrogen dioxide emissions derived from space with TROPOMI: methodology and validation

“…During the ECCC's aircraft campaign over the AOSR (Griffin et al, 2019), there was an opportunity to measure downwind of a boreal forest wildfire. A large suite of measurements were taken of the Lac La Loche fire on June 25, 2018 that originated in Saskatchewan, Canada, at approximately 56 • N, 110 • W (Ditto et al, 2021;McLagan et al, 2021). The aircraft was equipped with two Thermo Scientific Model 42i-TL (NO-NO 2 -NO x ) analyzers, modified to measure at 1-Hz time resolution, with an uncertainty of 3 % +0.4 ppbv, and an estimated detection limit of 0.2 ppbv (Griffin et al, 2019).…”

“…The NO 2 to NO x conversion is explored with model output and aircraft observations. Lastly, we compare the TROPOMI NO 2 vertical column densities (VCDs) and emission estimates to those obtained by four different aircraft campaigns in the Western United States and Canada during the 2018 and 2019 summers: (1) the Environment and Climate Change Canada's 2018 aircraft campaign over the Athabasca Oil Sand Region (AOSR) (Griffin et al, 2019;Ditto et al, 2021;McLagan et al, 2021), (2) the Western-Wildfire Experiment for Cloud Chemistry, Aerosol Absorption and Nitrogen (WE-CAN; https://www.eol.ucar.edu/field_projects/we-can; last accessed: 19 July 2021) campaign, (3) the Biomass Burning Fluxes of Trace Gases and Aerosols (BB-FLUX) campaign (Theys et al, 2020;Kille et al, 2021), and (4) the Fire Influence on Regional to Global Environments Experiment -Air Quality (FIREX-AQ; https://www.esrl.noaa.gov/csd/projects/firex-aq/; last accessed: 19 July 2021) campaign. This paper is structured as follows: Section 2 describes the data sets used.…”

Biomass burning nitrogen dioxide emissions derived from space with TROPOMI: methodology and validation

“…The NO 2 -to-NO x conversion is explored with model output and aircraft observations. Lastly, we compare the TROPOMI NO 2 vertical column densities (VCDs) and emission estimates to those obtained by four different aircraft campaigns in the western United States and Canada during the 2018 and 2019 summers: (1) Environment and Climate Change Canada's 2018 aircraft campaign over the Athabasca Oil Sands Region (AOSR) (Griffin et al, 2019;Ditto et al, 2021;McLagan et al, 2021), (2) the Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption and Nitrogen (WE-CAN; https://www.eol.ucar.edu/field_projects/we-can, last access: 19 July 2021) campaign, (3) the Biomass Burning Fluxes of Trace Gases and Aerosols (BB-FLUX) campaign (Theys et al, 2020;Kille et al, 2021), and (4) the Fire Influence on Regional to Global Environments Experiment -Air Quality (FIREX-AQ; https://www.esrl.noaa.gov/csd/ projects/firex-aq/, last access: 19 July 2021) campaign. This paper is structured as follows: Sect.…”

Research on the Setting of Australian Mountain Fire Emergency Center Based on K-Means Algorithm

“…It is a natural disaster that is sudden, destructive, and difficult to handle and salvage [1]. It is a kind of fire that occurs during the seasonal alternation of severe dryness and continuous high temperature and is the main contributor to the active gas phase and particulate phase organic compounds in the atmosphere [2]. As climate warming intensifies, the frequency and intensity of global forest fire disasters will also increase.…”

“…Australia is the country with the largest area in Oceania and the country with the most severe wildfire problem. On average, there are more than 50,000 wildfires every year, and about 50 million hm 2 of forest and grassland are destroyed by wildfires [5]. e disastrous forest fires in Australia from October 2019 to February 2020 have made humankind more clearly aware of the enormous impact of wildfires on the environment and climate.…”