Comment on acp-2022-297

Published: June 3, 2022

Abstract. The size and frequency of wildfires in the western United States have been increasing, this trend is projected to continue, with increasing adverse consequences for human health. Gas- particle-phase organic compounds are main components wildfire emissions. Some directly emitted hazardous air pollutants, while others can react oxidants form secondary pollutants such as ozone aerosol (SOA). Further, particle phase volatize during smoke transport then serve precursors SOA. extent pollutant formation from emissions dependent part on speciation compounds. most detailed has achieved laboratory studies, though recent field campaigns leading an increase measurements field. In study, we identified quantified hundreds gas- conifer-dominated US, using two two-dimensional gas chromatography coupled time-of-flight mass spectrometry (GC × GC ToF-MS) instruments. Observed emission factors (EFs) ratios reported four wildfires. As demonstrated previously, modified combustion efficiency (MCE) was a good predictor EFs (e.g., R²=0.78 0.84 sugars terpenoids, respectively), except elemental carbon. Higher diterpenoids, resin acids, monoterpenes were observed relative likely due distillation unburned heated vegetation, which may be underrepresented studies. These diterpenoids acids accounted up 45 % total aerosol, higher than contribution sugar derivatives. low volatility makes them ideal markers conifer fire smoke. speciated also show that evaporation semi-volatile took place plumes, suggests evaporated primary precursor SOAs plumes.

Language: Английский

Comment on acp-2022-297

Published: June 29, 2022

Abstract. The size and frequency of wildfires in the western United States have been increasing, this trend is projected to continue, with increasing adverse consequences for human health. Gas- particle-phase organic compounds are main components wildfire emissions. Some directly emitted hazardous air pollutants, while others can react oxidants form secondary pollutants such as ozone aerosol (SOA). Further, particle phase volatize during smoke transport then serve precursors SOA. extent pollutant formation from emissions dependent part on speciation compounds. most detailed has achieved laboratory studies, though recent field campaigns leading an increase measurements field. In study, we identified quantified hundreds gas- conifer-dominated US, using two two-dimensional gas chromatography coupled time-of-flight mass spectrometry (GC × GC ToF-MS) instruments. Observed emission factors (EFs) ratios reported four wildfires. As demonstrated previously, modified combustion efficiency (MCE) was a good predictor EFs (e.g., R²=0.78 0.84 sugars terpenoids, respectively), except elemental carbon. Higher diterpenoids, resin acids, monoterpenes were observed relative likely due distillation unburned heated vegetation, which may be underrepresented studies. These diterpenoids acids accounted up 45 % total aerosol, higher than contribution sugar derivatives. low volatility makes them ideal markers conifer fire smoke. speciated also show that evaporation semi-volatile took place plumes, suggests evaporated primary precursor SOAs plumes.

Language: Английский