Significant reduction of PM 2.5 in eastern China due to regional-scale emission control: evidence from SORPES in 2011–2018
Haze pollution caused by PM2.5 is the largest air quality concern in China in recent years. Long-term measurements of PM2.5 and the precursors and chemical speciation are crucially important for evaluating the efficiency of emission control, understanding formation and transport of PM2.5 associated...
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Published in | Atmospheric chemistry and physics Vol. 19; no. 18; pp. 11791 - 11801 |
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Main Authors | , , , , , , , , , , , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
24.09.2019
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Online Access | Get full text |
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Summary: | Haze pollution caused by PM2.5 is the largest air
quality concern in China in recent years. Long-term measurements of
PM2.5 and the precursors and chemical speciation are crucially important
for evaluating the efficiency of emission control, understanding formation
and transport of PM2.5 associated with the change of meteorology, and
accessing the impact of human activities on regional climate change.
Here we reported long-term continuous measurements of PM2.5, chemical
components, and their precursors at a regional background station, the
Station for Observing Regional Processes of the Earth System (SORPES), in
Nanjing, eastern China, since 2011. We found that PM2.5 at the station
has experienced a substantial decrease (−9.1 % yr−1), accompanied by even
a very significant reduction of SO2 (−16.7 % yr−1), since the national
“Ten Measures of Air” took action in 2013. Control of open biomass
burning and fossil-fuel combustion are the two dominant factors that
influence the PM2.5 reduction in early summer and winter, respectively.
In the cold season (November–January), the nitrate fraction was significantly
increased, especially when air masses were transported from the north. More NH3
available from a substantial reduction of SO2 and increased oxidization
capacity are the main factors for the enhanced nitrate formation. The
changes of year-to-year meteorology have contributed to 24 % of the PM2.5
decrease since 2013. This study highlights several important implications on
air pollution control policy in China. |
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ISSN: | 1680-7324 1680-7324 |
DOI: | 10.5194/acp-19-11791-2019 |