In:
Atmospheric Chemistry and Physics, Copernicus GmbH, Vol. 22, No. 7 ( 2022-04-13), p. 4909-4928
Abstract:
Abstract. Ozone (O3), a potent greenhouse gas that is detrimental to
human health, is typically found in elevated concentrations within biomass
burning (BB) smoke plumes. The radical species OH, HO2, and RO2
(known collectively as ROx) have central roles in the formation of secondary
pollutants including O3 but are poorly characterized for BB plumes. We
present measurements of total peroxy radical concentrations ([XO2] ≡ [HO2] + [RO2]) and additional trace-gas and
particulate matter measurements from McCall, Idaho, during August 2018. There
were five distinct periods in which BB smoke impacted this site. During BB
events, O3 concentrations were enhanced, evident by ozone
enhancement ratios (ΔO3/ΔCO) that ranged up to 0.06 ppbv ppbv−1. [XO2] was similarly elevated during some BB events.
Overall, instantaneous ozone production rates (P(O3)) were
minimally impacted by the presence of smoke as [NOx] enhancements were minimal. Measured XO2 concentrations were compared to zero-dimensional
box modeling results to evaluate the Master Chemical
Mechanism (MCM) and GEOS-Chem mechanisms overall and during periods of BB
influence. The models consistently overestimated XO2 with the base MCM
and GEOS-Chem XO2 predictions high by an average of 28 % and 20 %,
respectively. One period of BB influence had distinct measured enhancements
of 15 pptv XO2 that were not reflected in the model output, likely due
to the presence of unmeasured HOx sources. To the best of our knowledge, this is the
first BB study featuring peroxy radical measurements.
Type of Medium:
Online Resource
ISSN:
1680-7324
DOI:
10.5194/acp-22-4909-2022
DOI:
10.5194/acp-22-4909-2022-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2022
detail.hit.zdb_id:
2092549-9
detail.hit.zdb_id:
2069847-1
Permalink