es6b06408_si_001.pdf (1.47 MB)
Significant Increase of Aromatics-Derived Secondary Organic Aerosol during Fall to Winter in China
journal contribution
posted on 2017-06-07, 00:00 authored by Xiang Ding, Yu-Qing Zhang, Quan-Fu He, Qing-Qing Yu, Jun-Qi Wang, Ru-Qin Shen, Wei Song, Yue-Si Wang, Xin-Ming WangHuman
activities release large amounts of anthropogenic pollutants
into the air, and thereby produce substantial secondary organic aerosol
(SOA). Aromatic hydrocarbons (AHs) that mainly emitted from coal combustion,
transportation, solvent use and biofuel/biomass burning, are a major
class of anthropogenic SOA precursors. At present, there are few field
studies focusing on AH-derived SOA (SOAA) on a continental
scale, especially in polluted regions of the world. In this study,
a one-year concurrent observation of the SOAA tracer, 2,3-dihydroxy-4-oxopentanoic
acid (C5H8O5, DHOPA) was carried
out at 12 sites across six regions of China for the first time. The
annual averages of DHOPA among the 12 sites ranged from 1.23 to 8.83
ng m–3 with a mean of 3.48 ± 1.96 ng m–3. At all observation sites, the concentrations of
DHOPA from fall to spring were significantly higher than those in
summertime, and positive correlations were observed between DHOPA
and the biomass burning tracer (levoglucosan). This indicated that
such a nationwide increase of SOAA during the cold period
was highly associated with the enhancement of biomass burning emission.
In the northern China, the highest levels of DHOPA were observed in
the coldest months during winter, probably due to the enhancement
of biofuel and coal consumption for household heating. In the southern
China, the highest levels of DHOPA were mostly observed in fall and
spring, which were associated with the enhancement of open biomass
burning. The apparent increases of DHOPA and levoglucosan levels during
the cold period and the negative correlations of visibility with DHOPA
and levoglucosan imply that the reduction of SOAA amount
and biomass burning emission is an efficient way to reduce haze pollution
during fall to winter in China.