Abstract. A regional fully coupled meteorology–chemistry model, Weather Research and
Forecasting model with Chemistry (WRF-Chem), was employed to study the
seasonality of ozone (O3) pollution and its sources in both China and
India. Observations and model results suggest that O3 in the North
China Plain (NCP), Yangtze River Delta (YRD), Pearl River Delta (PRD), and
India exhibit distinctive seasonal features, which are linked to the
influence of summer monsoons. Through a factor separation approach, we
examined the sensitivity of O3 to individual anthropogenic, biogenic,
and biomass burning emissions. We found that summer O3 formation in
China is more sensitive to industrial and biogenic sources than to other
source sectors, while the transportation and biogenic sources are more
important in all seasons for India. Tagged simulations suggest that local
sources play an important role in the formation of the summer O3 peak
in the NCP, but sources from Northwest China should not be neglected to
control summer O3 in the NCP. For the YRD region, prevailing winds and
cleaner air from the ocean in summer lead to reduced transport from polluted
regions, and the major source region in addition to local sources is
Southeast China. For the PRD region, the upwind region is replaced by
contributions from polluted PRD as autumn approaches, leading to an autumn
peak. The major upwind regions in autumn for the PRD are YRD (11 %) and
Southeast China (10 %). For India, sources in North India are more
important than sources in the south. These analyses emphasize the relative
importance of source sectors and regions as they change with seasons,
providing important implications for O3 control strategies.
Ambient ozone pollution and years of life lost: Association, effect modification, and additional life gain from a nationwide analysis in China
