Unprecedented decline in summertime surface ozone over eastern China in 2020 comparably attributable to anthropogenic emission reductions and meteorology
China’s nationwide monitoring network initiated in 2013 has witnessed continuous increases of urban summertime surface ozone to 2019 by about 5% year ^−1 , among the fastest ozone trends in the recent decade reported in the Tropospheric ozone assessment report. Here we report that surface ozone leve...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2021-01-01
|
| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/ac3e22 |
| _version_ | 1797747071671861248 |
|---|---|
| author | Hao Yin Xiao Lu Youwen Sun Ke Li Meng Gao Bo Zheng Cheng Liu |
| author_facet | Hao Yin Xiao Lu Youwen Sun Ke Li Meng Gao Bo Zheng Cheng Liu |
| author_sort | Hao Yin |
| collection | DOAJ |
| description | China’s nationwide monitoring network initiated in 2013 has witnessed continuous increases of urban summertime surface ozone to 2019 by about 5% year ^−1 , among the fastest ozone trends in the recent decade reported in the Tropospheric ozone assessment report. Here we report that surface ozone levels averaged over cities in eastern China cities decrease by 5.5 ppbv in May–August 2020 compared to the 2019 levels, representing an unprecedented ozone reduction since 2013. We combine the high-resolution GEOS-Chem chemical model and the eXtreme Gradient Boosting (XGBoost) machine learning model to quantify the drivers of this reduction. We estimate that changes in anthropogenic emissions alone decrease ozone by 3.2 (2.9–3.6) ppbv (57% of the total 5.5 ppbv reduction) averaged over cities in eastern China and by 2.5 ∼ 3.2 ppbv in the three key city clusters for ozone mitigation. These reductions appear to be driven by decreases in anthropogenic emissions of both nitrogen oxides (NO _x ) and volatile organic compounds, likely reflecting the stringent emission control measures implemented by The Chinese Ministry of Environmental and Ecology in summer 2020, as supported by observed decline in tropospheric formaldehyde (HCHO) and nitrogen dioxides (NO _2 ) from satellite and by bottom-up emission estimates. Comparable to the emission-driven ozone reduction, the wetter and cooler weather conditions in 2020 decrease ozone by 2.3 (1.9–2.6) ppbv (43%). Our analyses indicate that the current emission control strategies can be effective for ozone mitigation in China yet tracking future ozone changes is essential for further evaluation. Our study also reveals important potential to combine the mechanism-based, state-of-art atmospheric chemical models with machine learning model to improve the attribution of ozone drivers. |
| first_indexed | 2024-03-12T15:46:55Z |
| format | Article |
| id | doaj.art-5563debada2e44ec83c69f4582065d4b |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T15:46:55Z |
| publishDate | 2021-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-5563debada2e44ec83c69f4582065d4b2023-08-09T15:23:51ZengIOP PublishingEnvironmental Research Letters1748-93262021-01-01161212406910.1088/1748-9326/ac3e22Unprecedented decline in summertime surface ozone over eastern China in 2020 comparably attributable to anthropogenic emission reductions and meteorologyHao Yin0https://orcid.org/0000-0002-4399-5752Xiao Lu1https://orcid.org/0000-0002-5989-0912Youwen Sun2https://orcid.org/0000-0003-3126-3252Ke Li3Meng Gao4Bo Zheng5https://orcid.org/0000-0001-8344-3445Cheng Liu6https://orcid.org/0000-0002-3759-9219Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, HFIPS, Chinese Academy of Sciences , Hefei 230031, People’s Republic of China; University of Science and Technology of China , Hefei 230026, People’s Republic of ChinaSchool of Atmospheric Sciences, Sun Yat-sen University , Zhuhai 519082, People’s Republic of ChinaKey Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, HFIPS, Chinese Academy of Sciences , Hefei 230031, People’s Republic of ChinaJiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science and Technology , Nanjing 210044, People’s Republic of ChinaDepartment of Geography, Hong Kong Baptist University , Hong Kong 999077, People’s Republic of ChinaInstitute of Environment and Ecology, Tsinghua Shenzhen International Graduate School, Tsinghua University , Shenzhen 518055, People’s Republic of ChinaKey Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, HFIPS, Chinese Academy of Sciences , Hefei 230031, People’s Republic of China; Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China , Hefei 230026, People’s Republic of China; Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, University of Science and Technology of China , Hefei 230026, People’s Republic of China; Anhui Province Key Laboratory of Polar Environment and Global Change, University of Science and Technology of China , Hefei 230026, People’s Republic of China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen 361021, People’s Republic of ChinaChina’s nationwide monitoring network initiated in 2013 has witnessed continuous increases of urban summertime surface ozone to 2019 by about 5% year ^−1 , among the fastest ozone trends in the recent decade reported in the Tropospheric ozone assessment report. Here we report that surface ozone levels averaged over cities in eastern China cities decrease by 5.5 ppbv in May–August 2020 compared to the 2019 levels, representing an unprecedented ozone reduction since 2013. We combine the high-resolution GEOS-Chem chemical model and the eXtreme Gradient Boosting (XGBoost) machine learning model to quantify the drivers of this reduction. We estimate that changes in anthropogenic emissions alone decrease ozone by 3.2 (2.9–3.6) ppbv (57% of the total 5.5 ppbv reduction) averaged over cities in eastern China and by 2.5 ∼ 3.2 ppbv in the three key city clusters for ozone mitigation. These reductions appear to be driven by decreases in anthropogenic emissions of both nitrogen oxides (NO _x ) and volatile organic compounds, likely reflecting the stringent emission control measures implemented by The Chinese Ministry of Environmental and Ecology in summer 2020, as supported by observed decline in tropospheric formaldehyde (HCHO) and nitrogen dioxides (NO _2 ) from satellite and by bottom-up emission estimates. Comparable to the emission-driven ozone reduction, the wetter and cooler weather conditions in 2020 decrease ozone by 2.3 (1.9–2.6) ppbv (43%). Our analyses indicate that the current emission control strategies can be effective for ozone mitigation in China yet tracking future ozone changes is essential for further evaluation. Our study also reveals important potential to combine the mechanism-based, state-of-art atmospheric chemical models with machine learning model to improve the attribution of ozone drivers.https://doi.org/10.1088/1748-9326/ac3e22ozone changesanthropogenic emission reductionsmeteorologyGEOS-Chem-XGBoostozone mitigation |
| spellingShingle | Hao Yin Xiao Lu Youwen Sun Ke Li Meng Gao Bo Zheng Cheng Liu Unprecedented decline in summertime surface ozone over eastern China in 2020 comparably attributable to anthropogenic emission reductions and meteorology Environmental Research Letters ozone changes anthropogenic emission reductions meteorology GEOS-Chem-XGBoost ozone mitigation |
| title | Unprecedented decline in summertime surface ozone over eastern China in 2020 comparably attributable to anthropogenic emission reductions and meteorology |
| title_full | Unprecedented decline in summertime surface ozone over eastern China in 2020 comparably attributable to anthropogenic emission reductions and meteorology |
| title_fullStr | Unprecedented decline in summertime surface ozone over eastern China in 2020 comparably attributable to anthropogenic emission reductions and meteorology |
| title_full_unstemmed | Unprecedented decline in summertime surface ozone over eastern China in 2020 comparably attributable to anthropogenic emission reductions and meteorology |
| title_short | Unprecedented decline in summertime surface ozone over eastern China in 2020 comparably attributable to anthropogenic emission reductions and meteorology |
| title_sort | unprecedented decline in summertime surface ozone over eastern china in 2020 comparably attributable to anthropogenic emission reductions and meteorology |
| topic | ozone changes anthropogenic emission reductions meteorology GEOS-Chem-XGBoost ozone mitigation |
| url | https://doi.org/10.1088/1748-9326/ac3e22 |
| work_keys_str_mv | AT haoyin unprecedenteddeclineinsummertimesurfaceozoneovereasternchinain2020comparablyattributabletoanthropogenicemissionreductionsandmeteorology AT xiaolu unprecedenteddeclineinsummertimesurfaceozoneovereasternchinain2020comparablyattributabletoanthropogenicemissionreductionsandmeteorology AT youwensun unprecedenteddeclineinsummertimesurfaceozoneovereasternchinain2020comparablyattributabletoanthropogenicemissionreductionsandmeteorology AT keli unprecedenteddeclineinsummertimesurfaceozoneovereasternchinain2020comparablyattributabletoanthropogenicemissionreductionsandmeteorology AT menggao unprecedenteddeclineinsummertimesurfaceozoneovereasternchinain2020comparablyattributabletoanthropogenicemissionreductionsandmeteorology AT bozheng unprecedenteddeclineinsummertimesurfaceozoneovereasternchinain2020comparablyattributabletoanthropogenicemissionreductionsandmeteorology AT chengliu unprecedenteddeclineinsummertimesurfaceozoneovereasternchinain2020comparablyattributabletoanthropogenicemissionreductionsandmeteorology |