Mitigating NO_x emissions does not help alleviate wintertime particulate pollution in Beijing-Tianjin-Hebei (BTH), China
Abstract
Stringent mitigation measures have reduced wintertime PM_(2.5) concentrations by 42.2% from 2013 to 2018 in the BTH. The observed nitrate aerosols have not exhibited a significant decreasing trend and constituted a major fraction (about 20%) of the total PM_(2.5), although the surface-measured NO₂ level has decreased by over 20%. It still remains elusive about contributions of nitrogen oxides (NO_x) emissions mitigation to the nitrate and PM_(2.5) level. The WRF-Chem model simulations of a persistent haze episode in January 2019 in the BTH reveal that NO_x emissions mitigation does not help lower wintertime nitrate and PM_(2.5) concentrations under current conditions in the BTH, because the substantial O₃ increase induced by NO_x mitigation offsets the HNO₃ loss and enhances sulfate and secondary organic aerosols formation. Our results are further consolidated by occurrence of the severe PM pollution in the BTH during the COVID-19 outbreak with a significant reduction of NO₂.
Additional Information
Published Online: Wed, 2 Sep 2020. This work is financially supported by the Strategic Priority Research Program of Chinese Academy of Sciences (XDB40030203), the National Key R&D Plan (2017YFC0210000), and National Research Program for Key Issues in Air Pollution Control (DQGG0105).Attached Files
Submitted - essoar.10504089.1.pdf
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Additional details
- Eprint ID
- 106278
- Resolver ID
- CaltechAUTHORS:20201026-104108282
- XDB40030203
- Chinese Academy of Sciences
- 2017YFC0210000
- National Key Research and Development Program of China
- DQGG0105
- National Research Program for Key Issues in Air Pollution Control
- Created
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2020-10-26Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field