Effect analysis of meteorological conditions on air quality during the winter COVID-19 lockdown in Beijing
YIN Xiao-mei1,2, LI Zi-ming2, QIAO lin2, LIU Xiang-xue2, GUO Heng2, WU Jin2, ZHU Xiao-wan2, QIU Yu-lu2, WANG Ji-kang3, ZHANG Xiao-ye4
1. Institute of Urban Meteorology, China Meteorological Administration, Beijing 100089, China; 2. Environment Meteorology Forecast Center of Beijing-Tianjin-Hebei, China Meteorological Administration, Beijing 100089, China; 3. National Meteorological Center of China Meteorological Administration, Beijing 100081, China; 4. State Key Laboratory of Severe Weather & Key Laboratory of Atmospheric Chemistry of CMA, Chinese Academy of Meteorological Sciences, Beijing 100081, China
Abstract：The influence of meteorological conditions on the pollution processes was investigated in this study by analyzing the changes of air quality as well as the characteristics of two persistent heavy pollution episodes during the Coronavirus Disease 2019 (COVID-19) prevention (January 24 to February 29) of 2020 winter compared with the same period of 2015~2019. Cold air intensity in 2020 winter was weaker with the cold surges frequency decreased by 50%. Air temperature was 0.73℃ higher, and wind speed and mixed layer height were 17.8% and 32.5% lower, respectively. Relative humidity and dew point temperature increased by 60.9% and 48.1%, respectively. Northerly wind frequency reduced 7.5% while both of southerly and easterly wind increased 6.0%. As shown above, all meteorological conditions in 2020 winter were significantly more favorable for air pollution than the same historical period. Moreover, two heavy pollution episodes (January 24~29 and February 8~14) lasted for 59 and 75 hours were analyzed. At the cumulative stage, regional transport that can be divided into east and south channel greatly affected PM2.5, with the contribution of 70% and 58% for two episodes. By contrast, the contribution of local pollution was 67% and 48%, respectively, indicating the increased proportion of hygroscopic growth and secondary generation in the maintenance and aggravation stages. Under the meteorological background of "high humidity and high atmospheric stability", the combined effects of atmospheric vertical dynamics and horizontal convergence accumulated PM2.5 and water vapor in Beijing plain and prevented them from spreading beyond the boundary layer. Further bidirectional feedback between increased pollutants and meteorological factors in stable boundary layer resulting in aggravation of pollution. According to EMI index, meteorological conditions during the epidemic prevention in 2020 winter caused an increase of 70.1% in PM2.5 concentration compared to pre-COVID-19. Emissions reduction caused by emergency measures for COVID-19lockdown offset 53% of the adverse impact induced by meteorological conditions. As for the two episodes in 2020 winter, EMI was 26.9% and 19.7% larger than the average of other nine episodes in the corresponding period of 2015~2019, and PM2.5 concentration was basically unchanged or slightly reduced. Overall, if the current social emission level is not changed, emission reduction caused by city blockade under special circumstances can only partially reduce the pollution concentration, however, cannot completely offset the adverse impact of meteorological conditions.
李令军,王英,李金香,等.2000~2010北京大气重污染研究[J]. 中国环境科学, 2012,32(1):23-30. Li L J, Wang Y, Li J X, et al. The analysis of heavy air pollution in Beijing during 2000~2010[J]. China Environmental Science, 2012, 32(1):23-30.
孙婷婷,张天舒,项衍,等.2018年春节期间京津冀地区污染过程分析[J]. 中国环境科学, 2020,40(4):1393-1402. Sun T T, Zhang T S, Xiang Y, et al. Analysis of the pollution process in the Beijing-Tianjin-Hebei region during the Spring Festival of 2018[J]. China Environmental Science, 2020,40(4):1393-1402.
张蒙,韩力慧,刘保献,等.北京市冬季重污染期间PM2.5及其组分演变特征[J]. 中国环境科学, 2020,40(7):2829-2838. Zhang M, Han Li H, Liu B X, et al. Evolution of PM2.5 and its components during heavy pollution episodes in winter in Beijing[J]. China Environmental Science, 2020,40(7):2829-2838.
李军,王京丽,屈坤.相对湿度和PM2.5浓度对乌鲁木齐市冬季能见度的影响[J]. 中国环境科学, 2020,40(8):3322-3331. Li J, Wang J L, Qu K. Impacts of relative humidity and PM2.5 concentration on atmospheric visibility during winter in Urumqi Urban Area[J]. China Environmental Science, 2020,40(8):3322-3331.
Chen X, Zhang L W, Huang J J, et al. Long-term exposure to urban air pollution and lung cancer mortality:A 12-year cohort study in Northern China[J]. Science of the Total Environment, 2016,571:855-861.
Huang H, Jiang Y, Xu X, et al. In vitro bioaccessibility and health risk assessment of heavy metals in atmospheric particulate matters from three different functional areas of Shanghai, China[J]. Science of the Total Environment, 2017,610-611:646-554.
Liao Z H, Gao M, Sun J R, et al. The impact of synoptic circulation on air quality and pollution-related human health in the Yangtze River delta region[J]. Science of the Total Environment, 2017,607:838-846.
Zhang J P, Zhu T, Zhang Q H, et al. The impact of circulation patterns on regional transport pathways and air quality over Beijing and its surroundings[J]. Atmospheric Chemistry and Physics, 2012,11(12):33465-33509.
Liu T, Gong S, He J, et al. Attributions of meteorological and emission factors to the 2015winter severe haze pollution episodes in China's Jing-Jin-Ji area[J]. Atmospheric Chemistry and Physics, 2017,17(4):2971-2980.
Song C B, Wu L, Xie Y C, et al. Air pollution in China:status and spatiotemporal variations[J]. Environmental Pollution, 2017,227:334-347.
钟嶷盛,周颖,程水源,等.首都重大活动与空气重污染应急减排措施效果对比分析[J]. 环境科学, 2020,41(8):3449-3457. Zhong Y S, Zhou Y, Cheng S Y, et al. Comparison analysis of the effect of emission reduction measures for major events and heavy air pollution in the Capital[J]. Environmental Science, 2020,41(8):3449-3457.
Liu X, Li C, Tu H, et al. Analysis of the effect of meteorological factors on PM2.5-associated PAHs during autumn-winter in urban Nanchang[J]. Aerosol and Air Quality Research, 2016,16:3222-3229.
Gui K, Che H., Wang Y, et al. Satellite-derived PM2.5 concentration trends over Eastern China from 1998 to 2016:Relationships to emissions and meteorological parameters[J]. Environment Pollution, 2019,247:1125-1133.
Shi C, Yuan R, Wu B, et al. Meteorological conditions conducive to PM2.5 pollution in winter 2016/2017 in the Western Yangtze River Delta, China[J]. Science of the Total Environment, 2018,642:1221-1232.
Ma S, Xiao Z, Zhang Y, et al. Assessment of meteorological impact and emergency plan for a heavy haze pollution episode in a core city of the North China Plain[J]. Aerosol and Air Quality Research, 2020,20(1):26-42.
北京市生态环境局.2019年北京市生态环境状况公报[EB/OL]. 2020,http://sthjj.beijing.gov.cn/bjhrb/index/xxgk69/sthjlyzwg/1718880/1718881/1718882/1791057/index.html. Beijing Municipal Bureau of Ecology and Environment. Beijing ecology and environment statement 2019[EB/OL]. 2020, http://sthjj.beijing.gov.cn/bjhrb/index/xxgk69/sthjlyzwg/1718880/1718881/1718882/1791057/index.html.
Urrutia-Pereira M, Mello-Da-Silva C A, Solé D. COVID-19 and air pollution:A dangerous association?[J]. Allergologia et Immunopathologia, 2020,48(5):496-499.
Higham J E, Ramirez C A, Green M A, et al. UK covid-19 lockdown:100 days of air pollution reduction?[J]. Air Quality, Atmosphere and Health, 2021,14:325-332.
Yao Y, Pan J, Wang W, et al. Association of particulate matter pollution and case fatality rate of COVID-19 in 49 Chinese cities[J]. Science of the Total Environment, 2020,741:140396.
Yao Y, Pan J, Liu Z X, et al. Temporal association between particulate matter pollution and case fatality rate of COVID-19in Wuhan[J]. Environmental Research, 2020,189:109941.
Berman J D, Ebisu K. Changes in U.S. air pollution during the COVID-19pandemic[J]. Science of the Total Environment, 2020,739:139864.
Wang C, Horby P W, Hayden F G, et al. A novel coronavirus outbreak 258 of global health concern[J]. Lancet, 2020,395(470):496-496.
乐旭,雷亚栋,周浩,等.新冠肺炎疫情期间中国人为碳排放和大气污染物的变化[J]. 大气科学学报, 2020,43(2):265-274. Le X, Lei Y D, Zhou H, et al. Changes of anthropogenic carbon emissions and air pollutants during the COVID-19epidemic in China[J]. Transactions of Atmospheric Sciences, 2020,43(2):265-274.
NASA Goddard Space Flight Center. Airborne nitrogen dioxide plummets over China[EB/OL]. 2020, https://earthobservatory.nasa. gov/images/146362/airborne-nitrogen-dioxide-plummets-over-china.
肖致美,徐虹,蔡子颖,等.2020年天津市两次重污染天气污染特征分析[J]. 环境科学, 2020,41(9):3879-3888. Xiao Z M, Xu H, Cai Z Y, et al. Characterization of two heavy pollution episodes in Tianjin in 2020[J]. Environmental Science, 2020,41(9):3879-3888.
QX/T 479-2019 PM2.5气象条件评估指数(EMI)[S]. QX/T 479-2019 Evaluation on meteorological condition index of PM2.5 pollution (EMI)[S].
王继康,徐峻,何友江,等.利用源示踪技术计算日本和韩国低层大气SO2和SO42-来源[J]. 环境科学研究, 2014,27(6):582-588. Wang J K, Xu J, He Y J, et al. Source apportionment of sulfur in the lower atmosphere of Japan and Korea using tag method[J]. Research of Environmental Sciences, 2014,27(6):582-588.
王继康,花丛,桂海林,等.2016年1月我国中东部一次大气污染物传输过程分析[J]. 气象, 2017,(7):804-812. Wang J K, Hua C, Gui H L, et al. Transport of PM2.5 of the haze pollution episode over mid-eastern China in January 2016[J]. Meteorological, 2017,(7):804-812.
关攀博,周颖,程水源,等.典型重工业城市空气重污染过程特征与来源解析[J]. 中国环境科学, 2020,40(1):31-40. Guang P B, Zhou Y, Cheng S Y, et al. Characteristics of heavy pollution process and source appointment in typical heavy industry cities[J]. China Environmental Sciences, 2020,40(1):31-40.
Stein A F, Draxler R R, Rolph G D, et al. NOAA's HYSPLIT atmospheric transport and dispersion modeling system[J]. Bulletin of the American Meteorological Society, 2015,96(12):2059-2077.
王茜.利用轨迹模式研究上海大气污染的输送来源[J]. 环境科学研究, 2013,26(4):357-363. Wang Q. Study of air pollution transportation source in Shanghai using trajectory model[J]. Research of Environmental Sciences, 2013,26(4):357-363.
Chen D, Liu X, Lang J, et al. Estimating the contribution of regional transport to PM2.5 air pollution in a rural area on the North China Plain[J]. Science of the Total Environment, 2017,583:280-291.https://doi.org/10.1016/j.scitotenv.2017.01.066.
吴国雄,李占清,符淙斌,等.气溶胶与东亚季风相互影响的研究进展[J]. 中国科学:地球科学, 2015,45(11):1609-1627. Wu G X, Li Z Q, Fu C B, et al. Advances in studying interactions between aerosols and monsoon in China[J]. Science China:Earth Sciences, 2015,45(11):1609-1627.
朱艳峰.一个适用于描述中国大陆冬季气温变化的东亚冬季风指数[J]. 气象学报, 2008,66(5):781-788. Zhu Y F. An index of East Asian winter monsoon applied to description the Chinese mainland winter temperature changes[J]. Acta Meteorologica Sinica, 2008,66(5):781-788.
Zhong J, Zhang X, Wang Y. Reflections on the threshold for PM2.5 explosive growth in the cumulative stage of winter heavy aerosol pollution episodes (HPEs) in Beijing[J]. Tellus B:Chemical and Physical Meteorology, 2019,71(1):1528134.
Zhang X, Zhong J, Wang J, et al. The interdecadal worsening of weather conditions affecting aerosol pollution in the Beijing area in relation to climate warming[J]. Atmospheric Chemistry & Physics, 2018,18:5991-5999.
杨元琴,王继志,张小曳,等.2017年1月沈阳和松辽平原地区重污染过程气象条件影响机理分析[J]. 气象与环境学报, 2018,34(6):116-124. Yang Y Q, Wang Z Z, Zhang X Y, et al. Influence mechanism of meteorological conditions on a heavy pollution event in Shenyang and the Songliao Plain during January 2017[J]. Journal of Meteorology and Environment, 2018,34(6):116-124.
Zhang X Y, Xu X D, Ding Y H, et al. The impact of meteorological changes from 2013 to 2017 on PM2.5 mass reduction in key regions in China[J]. Science China Earth Sciences, 2019,62(12):1885-1902.
Zhang Q, Quan J, Tie X. Effects of meteorology and secondary particle formation on visibility during heavy haze events in Beijing, China[J]. ence of the Total Environment, 2015,502:578-584.
Huang X, Ding A J, Gao J, et al. Enhanced secondary pollution offset reduction of primary emissions during COVID-19 lockdown in China[J]. National Science Review, 2020,nwaa137, https://doi.org/10.1093/nsr/nwaa137.