In:
Atmospheric Chemistry and Physics, Copernicus GmbH, Vol. 18, No. 20 ( 2018-10-26), p. 15451-15470
Abstract:
Abstract. We report the emissions of glyoxal and methylglyoxal from the open burning of
biomass during the NOAA-led 2016 FIREX intensive at the Fire Sciences
Laboratory in Missoula, MT. Both compounds were measured using cavity-enhanced spectroscopy, which is both more sensitive and more selective than
methods previously used to determine emissions of these two compounds. A
total of 75 burns were conducted, using 33 different fuels in 8 different
categories, providing a far more comprehensive dataset for emissions than was
previously available. Measurements of methylglyoxal using our instrument
suffer from spectral interferences from several other species, and the values
reported here are likely underestimates, possibly by as much as 70 %.
Methylglyoxal emissions were 2–3 times higher than glyoxal emissions on a
molar basis, in contrast to previous studies that report methylglyoxal
emissions lower than glyoxal emissions. Methylglyoxal emission ratios for all
fuels averaged 3.6±2.4 ppbv methylglyoxal (ppmv CO)−1, while emission
factors averaged 0.66±0.50 g methylglyoxal (kg fuel burned)−1. Primary
emissions of glyoxal from biomass burning were much lower than previous
laboratory measurements but consistent with recent measurements from
aircraft. Glyoxal emission ratios for all fuels averaged 1.4±0.7 ppbv glyoxal (ppmv CO)−1, while
emission factors averaged 0.20±0.12 g glyoxal (kg fuel burned)−1, values that are at least a factor of 4 lower than
assumed in previous estimates of the global glyoxal budget. While there was
significant variability in the glyoxal emission ratios and factors between
the different fuel groups, glyoxal and formaldehyde were highly correlated
during the course of any given fire, and the ratio of glyoxal to
formaldehyde, RGF, was consistent across many different fuel
types, with an average value of 0.068±0.018. While RGF values
for fresh emissions were consistent across many fuel types, further work is
required to determine how this value changes as the emissions age.
Type of Medium:
Online Resource
ISSN:
1680-7324
DOI:
10.5194/acp-18-15451-2018
DOI:
10.5194/acp-18-15451-2018-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2018
detail.hit.zdb_id:
2092549-9
detail.hit.zdb_id:
2069847-1
