Future changes in Beijing haze events under different anthropogenic aerosol emission scenarios
<p>Air pollution is a major issue in China and one of the largest threats to public health. We investigated future changes in atmospheric circulation patterns associated with haze events in the Beijing region and the severity of haze events during these circulation conditions from 2015 to 2049...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2021-05-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/21/7499/2021/acp-21-7499-2021.pdf |
| Summary: | <p>Air pollution is a major issue in China and one of the
largest threats to public health. We investigated future changes in
atmospheric circulation patterns associated with haze events in the Beijing
region and the severity of haze events during these circulation conditions from 2015 to 2049 under two different aerosol scenarios: a maximum
technically feasible aerosol reduction (MTFR) and a current legislation
aerosol scenario (CLE). In both cases greenhouse gas emissions follow the
Representative Concentration Pathway 4.5 (RCP4.5). Under RCP4.5 with CLE
aerosol the frequency of circulation patterns associated with haze events
increases due to a weakening of the East Asian winter monsoon via increased
sea level pressure over the North Pacific. The rapid reduction in
anthropogenic aerosol and precursor emissions in MTFR further increases the
frequency of circulation patterns associated with haze events, due to
further increases in the sea level pressure over the North Pacific and a
reduction in the intensity of the Siberian high. Even with the aggressive
aerosol reductions in MTFR periods of poor visibility, represented by above-normal aerosol optical depth (AOD), still occur in conjunction with
haze-favorable atmospheric circulation. However, the winter mean intensity
of poor visibility decreases in MTFR, so that haze events are less dangerous
in this scenario by 2050 compared to CLE and relative to the current
baseline. This study reveals the competing effects of aerosol emission
reductions on future haze events through their direct contribution to
pollutant source and their influence on the atmospheric circulation. A
compound consideration of these two impacts should be taken in future policy
making.</p> |
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| ISSN: | 1680-7316 1680-7324 |