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臭氧(O3)是一种强氧化剂,在许多大气化学过程中起着重要的作用[1-2]。10%的O3存在于对流层大气中,作为一种重要的大气污染气体,其浓度的升高,不仅对人体健康造成不同程度的伤害[3-5],同时对农业生产、生态系统等也造成影响[6-8]。2012年O3小时标准和8 h滑动平均浓度纳入常规大气环境监测项目[9],随后臭氧监测工作在我国各大城市大范围铺开,2019年全国PM2.5浓度与2018年持平,PM10较2018年下降了2.6%,但是O3较2018年上升了8.4%[10]。相对而言,O3浓度的影响因素更为复杂,治理难度更大。O3已经是继PM2.5之后,成为我国第二重要大气污染物。目前O3污染的相关研究已经成为大气环境领域的研究热点和难点之一。
近地面层O3主要来源于氮氧化合物(NOX)和挥发性有机物(VOCS)在太阳紫外辐射下,经过一系列复杂的链式光化学反应生成[11]。目前开展的O3污染研究主要有O3形成机制[12-13]、污染特征[14]和来源[15-16]、影响因素[17]及监测预报[18]等方面。例如,李霄阳等[14]对比了我国不同区域城市O3浓度月变化特征,发现北方城市和南方城市分别具有显著的倒“V”和“M”型月变化规律,且呈现夏季高、春秋季居中、冬季最低的特征。徐锟等[19]发现高温、低湿、强辐射有利于成都市夏季O3浓度升高,易造成污染。张小娟等[20]研究了上海城区O3长时间序列变化,发现夏季O3污染以中度污染居多,且年均增速为3.81 μg·(m3·a)−1。王旭东等[21]的研究发现,郑州市O3浓度2014—2018年增长速率为15.5 μg·(m3·a)−1,市区站点的主控因子为气温和相对湿度,而城郊站点为气温和风速。赵伟等[22]分析了2006—2019年珠三角地区臭氧污染趋势,结果表明珠三角O3浓度年平均增长率为0.8 μg·(m3·a)−1,2016年之后为2.08 μg·(m3·a)−1,增速加快,区域臭氧污染防治需要加强对前体物的协同控制。
海南省作为我国唯一一个热带海岛旅游省份,一直以生态自然环境良好著称。根据海南省生态环境厅的统计结果[23],发现2019年海南省空气质量优良天数较2018年上升1.5个百分点,PM2.5和PM10浓度持续下降。然而与此同时,海南省O3浓度维持较高水平,与2018年相比,O3浓度更是上升了11 μg·m−3。其中2019年9月更是发生了一次以O3为主要污染物的大气污染事件,较往年发生臭氧污染月份提前了一个月[24],而且具有强度强、持续时间长、发生范围广的显著特点。因此,本文基于该月空气质量和气象监测数据,结合FNL再分析资料,采用合成分析、相关分析和多元线性回归等统计方法,研究了大气环流背景对此次O3污染的持续性影响,同时讨论了气象因子的作用,以期为政府部门制定O3污染防治政策提供科学依据。
2019年9月海南省持续臭氧污染天气的气象条件分析
Meteorological conditions for the persistent ozone polluted event over Hainan Province in September 2019
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摘要: 2019年9月海南省(三沙市除外)发生了一次持续时间长、发生范围广的臭氧(ozone, O3)污染事件。本文利用环境监测资料、气象观测数据和FNL再分析资料,从O3污染概况、大气环流背景和O3污染天气演变过程的3个方面,探讨了气象条件在此次持续性O3污染过程中的作用。结果表明,污染时段(21—30日)的全省平均O3最大8 h平均浓度(O3−8 h)为146.3 μg·m−3,平均每天有6.3个市县的O3-8 h浓度超标,其中28日超标市县达到12个,海口市O3−8 h浓度超标持续的时间最长(9 d)。污染时段海南省受副高内部下沉气流影响,天气形势稳定。低层水平风速辐合,气象因子的垂直分布有助于增大混合层的湍流混合作用,这些气象背景场为O3污染的维持和发展提供了有利的气象条件。9月海南省日降水量、相对湿度和平均风速在逐日减小,而气压和日照时数在逐渐增加,平均气温维持在24℃以上,关键气象因子的变化特征有利于促进光化学反应速率,致使O3浓度维持较高水平。多元线性回归结果表明,关键气象因子回归的O3−8 h浓度与观测得到的O3−8 h浓度有较好的一致性,二者的相关系数高达0.93,通过了99.9%的信度检验,回归值对实测值的方差贡献达到0.86。Abstract: In September 2019, a long-lasting and wide-ranging ozone (O3) polluted event occurred in Hainan Province (except Sansha City). Using the environmental monitoring data, meteorological observation data and FNL reanalysis data, this study reveals the role of meteorological conditions in this long-persisting O3 pollution process, including the O3 polluted degree, atmospheric circulation background field and weather evolution of O3 pollution. The results show that the maximum 8h-averaged concentration of O3 (O3−8 h) reached 146.3 μg·m−3 in the polluted period (21—30 September), about 6.3 cities and counties exceeding the polluted standard of O3−8 h concentration every day in average during the polluted period. The maximum number of the polluted cities and counties reached to 12 on 28 September. Moreover, the longest polluted period (9 d) appeared in Haikou City. During the polluted period, Hainan Province was affected by the sinking airflow inside the subtropical high, with a stable weather condition. Low-level horizontal wind speed convergence and the vertical distribution of meteorological factors helps to increase the turbulent mixing of the mixed layer. The above meteorological fields provide favorable background for the maintenance and development of O3 pollution in Hainan Province. In addition, the daily precipitation, relative humidity, and average wind speed are decreasing, while the pressure and sunshine duration are gradually increasing day by day in September, and the average temperature is above 24℃ in Hainan Province. These key meteorological factors are conducive to the increase of the photochemical reaction rate, and result in the O3 concentration maintained at a high level. Furthermore, the results from the multiple linear regression show that O3−8 h concentration regressed by the key meteorological factors is in good agreement with the observed O3−8 h concentration, with a high correlation coefficient (0.93), exceeding the 99.9% confidence level. The variance contribution of the regression value reaches to 0.86.
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Key words:
- ozone /
- weather situation /
- meteorological factor /
- multiple regression /
- Hainan Province
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图 4 500 hPa清洁时段(a)和污染时段(b)位势高度场(黑色等值线,gpm)与风场(风羽,m·s−1)叠加,以及污染时段与清洁时段的位势高度(gpm,填色)和气温(℃,黑色等值线)差异(c)
Figure 4. Distribution of mean 500 hPa geopotential height (black contour, gpm) and wind fields (wind barbs, m·s−1) between clean period (a) and polluted period (b) and their difference (c) of geopotential height (gpm, color) and temperature (sheshidu℃, black contour)
图 5 925 hPa清洁时段(a)和污染时段(b)位势高度场(黑色等值线,gpm)与风场(矢量,m·s−1)叠加,以及污染时段与清洁时段的位势高度(gpm,填色)和气温(℃,黑色等值线)差异(c)
Figure 5. Distribution of mean 925 hPa geopotential height (black contour, gpm) and wind fields (vector, m·s−1) between clean period (a) and polluted period (b) and their difference (c) of geopotential height (gpm, color) and temperature (sheshidu℃, black contour)
表 1 海南省2019年9月月平均以及两个时段的O3−8 h浓度统计(单位:μg·m−3)
Table 1. Monthly mean, two periods of O3−8 h concentration and statistics result over Hainan Province in September 2019 (Unit: μg·m−3)
市县
City and
county月平均
Monthly
average清洁时段
Cleared
period污染时段
Polluted
period上升幅度
Rising
extent市县
City and
county月平均
Monthly
average清洁时段
Cleared
period污染时段
Polluted
period上升幅度
Rising
extent海口市 107.6 61.3 169.9 177.2% 屯昌县 102.6 52.8 165.7 213.8% 三亚市 86.7 45.0 149.4 232.0% 澄迈县 108.3 59.4 169.9 186.0% 五指山市 63.5 29.0 106.5 267.2% 临高县 101.2 66.6 141.9 113.1% 琼海市 77.5 40.4 127.8 216.3% 白沙县 83.9 44.7 134.8 201.6% 儋州市 77.8 44.5 126.8 184.9% 昌江县 89.7 47.2 147.4 212.3% 文昌市 111.8 77.2 160.4 107.8% 乐东县 82.3 38.3 143.2 273.9% 万宁市 80.1 41.9 132.8 216.9% 陵水县 98.6 53.3 161.1 202.3% 东方市 105.5 62.2 163.6 163.9% 琼中县 75.2 34.5 127.4 269.3% 定安县 105.4 60.8 166.7 174.2% 保亭县 75.1 19.4 138.1 611.9% 表 2 2019年9月海南省不同时段O3−8 h浓度值与气象因子的相关系数
Table 2. Correlation coefficients between O3−8 h and meteorological factors in different periods over Hainan Province in September 2019
时段
Period日降水量
Daily precipitation气压
Pressure平均气温
Average air temperature相对湿度
Relative humidity平均风速
Mean wind speed日照时数
Sunshine duration清洁时段 −0.597** 0.496 0.701** −0.721*** −0.642** 0.830*** 发展时段 −0.368 0.251 0.029 −0.507* 0.155 −0.392 污染时段 −0.285 0.254 0.191 0.125 −0.222 0.369 2019年9月 −0.518*** 0.965*** −0.240* −0.878*** −0.129 0.565*** 注:*表示通过90%信度检验,**表示通过95%信度检验,***表示通过99%信度检验.
Note: *means passed the 90% confidence level; ** means passed the 95% confidence level; *** means passed the 99%confidence level.表 3 2019年9月海南省不同时段O3−8 h浓度值与气象因子的观测值
Table 3. Observed value of O3−8 h and meteorological factors in different periods over Hainan Province in September 2019
时段
PeriodO3−8 h/
(μg·m−3)日降水量/mm
Daily precipitation气压/hPa
Pressure平均气温/℃
Average air temperature相对湿度/%
Relative humidity平均风速/(m·s−1)
Mean wind speed日照时数/(h·d−1)
Sunshine duration清洁时段 48.81 24.09 989.9 27.01 88.18 1.89 3.82 发展时段 77.05 4.19 996.05 27.52 81.5 1.47 7.26 污染时段 146.3 0.33 1001.02 26.4 73.11 1.74 7.89 2019年9月 90.72 9.54 995.66 26.98 80.93 1.7 6.32 -
[1] 汪明圣, 郭世昌. ENSO循环对东亚地区平流层臭氧分布的影响 [J]. 高原气象, 2017, 36(3): 865-874. doi: 10.7522/j.issn.1000-0534.2016.00068 WANG M S, GUO S C. Impact of the ENSO cycle on the stratospheric ozone distribution over east Asia [J]. Plateau Meteorology, 2017, 36(3): 865-874(in Chinese). doi: 10.7522/j.issn.1000-0534.2016.00068
[2] CHEN Z Y, LI R Y, CHEN D L, et al. Understanding the causal influence of major meteorological factors on ground ozone concentrations across China [J]. Journal of Cleaner Production, 2020, 242: 118498. doi: 10.1016/j.jclepro.2019.118498 [3] ANENBERG S C, HOROWITZ L W, TONG D Q, et al. An estimate of the global burden of anthropogenic ozone and fine particulate matter on premature human mortality using atmospheric modeling [J]. Environmental Health Perspectives, 2010, 118(9): 1189-1195. doi: 10.1289/ehp.0901220 [4] CROZE M L, ZIMMER L. Ozone atmospheric pollution and Alzheimer's disease: From epidemiological facts to molecular mechanisms [J]. Journal of Alzheimer's Disease, 2018, 62(2): 503-522. doi: 10.3233/JAD-170857 [5] LIU H, LIU S, XUE B R, et al. Ground-level ozone pollution and its health impacts in China [J]. Atmospheric Environment, 2018, 173: 223-230. doi: 10.1016/j.atmosenv.2017.11.014 [6] FUHRER J. Ozone risk for crops and pastures in present and future climates [J]. Naturwissenschaften, 2009, 96(2): 173-194. doi: 10.1007/s00114-008-0468-7 [7] 耿春梅, 王宗爽, 任丽红, 等. 大气臭氧浓度升高对农作物产量的影响 [J]. 环境科学研究, 2014, 27(3): 239-245. doi: 10.13198/j.issn.1001-6929.2014.03.03 GENG C M, WANG Z S, REN L H, et al. Study on the impact of elevated atmospheric ozone on crop yield [J]. Research of Environmental Sciences, 2014, 27(3): 239-245(in Chinese). doi: 10.13198/j.issn.1001-6929.2014.03.03
[8] 冯兆忠, 李品, 袁相洋, 等. 我国地表臭氧生态环境效应研究进展 [J]. 生态学报, 2018, 38(5): 1530-1541. FENG Z Z, LI P, YUAN X Y, et al. Progress in ecological and environmental effects of ground-level O3 in China [J]. Acta Ecologica Sinica, 2018, 38(5): 1530-1541(in Chinese).
[9] 中华人民共和国国家质量监督检验检疫总局, 中国国家标准化管理委员会. 中华人民共和国国家标准: 环境空气质量标准 GB 3095—2012[S]. 北京: 中国环境科学出版社, 2016. General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, Standardization Administration of the People's Republic of China. National Standard (Mandatory) of the People's Republic of China: Ambient air quality standard. GB 3095—2012[S]. Beijing: China Environment Science Press, 2016(in Chinese).
[10] 中华人民共和国生态环境部. 2019年中国生态环境状况公报[R]. http://www.mee.gov.cn/hjzl/sthjzk/zghjzkgb/202006/P020200602509464172096.pdf, 2020. [11] 符传博, 周航. 中国城市臭氧的形成机理及污染影响因素研究进展 [J]. 中国环境监测, 2021, 37(2): 33-43. FU C B, ZHOU H. Research progress on the formation mechanism and impact factors of urban ozone pollution in China [J]. Environmental Monitoring in China, 2021, 37(2): 33-43(in Chinese).
[12] C E J G. Global ozone budget and exchange between stratosphere and troposphere [J]. Tellus, 1962, 14(4): 363-377. doi: 10.3402/tellusa.v14i4.9563 [13] PANDIS S N, SEINFELD J H. Sensitivity analysis of a chemical mechanism for aqueous-phase atmospheric chemistry [J]. Journal of Geophysical Research Atmospheres, 1989, 94(D1): 1105. doi: 10.1029/JD094iD01p01105 [14] 符传博, 徐文帅, 丹利, 等. 2015—2018年海南省城市臭氧时空分布特征 [J]. 环境化学, 2020, 39(10): 2823-2832. doi: 10.7524/j.issn.0254-6108.2020042304 FU C B, XU W S, DAN L, et al. Spatiotemporal distribution of ozone in cities of Hainan from 2015 to 2018 [J]. Environmental Chemistry, 2020, 39(10): 2823-2832(in Chinese). doi: 10.7524/j.issn.0254-6108.2020042304
[15] 杨辉, 朱彬, 高晋徽, 等. 南京市北郊夏季挥发性有机物的源解析 [J]. 环境科学, 2013, 34(12): 4519-4528. YANG H, ZHU B, GAO J H, et al. Source apportionment of VOCs in the northern suburb of Nanjing in summer [J]. Environmental Science, 2013, 34(12): 4519-4528(in Chinese).
[16] WANG N, LYU X P, DENG X J, et al. Aggravating O3 pollution due to NOx emission control in Eastern China [J]. Science of the Total Environment, 2019, 677: 732-744. doi: 10.1016/j.scitotenv.2019.04.388 [17] 闫雨龙, 温彦平, 冯新宇, 等. 太原市城区臭氧变化特征及影响因素 [J]. 环境化学, 2016, 35(11): 2261-2268. doi: 10.7524/j.issn.0254-6108.2016.11.2016043001 YAN Y L, WEN Y P, FENG X Y, et al. Variation and the influence factors of ozone in urban area in Taiyuan [J]. Environmental Chemistry, 2016, 35(11): 2261-2268(in Chinese). doi: 10.7524/j.issn.0254-6108.2016.11.2016043001
[18] 刘烽, 徐怡珊. 臭氧数值预报模型综述 [J]. 中国环境监测, 2017, 33(4): 1-16. LIU F, XU Y S. Review of surface ozone modeling system [J]. Environmental Monitoring in China, 2017, 33(4): 1-16(in Chinese).
[19] 徐锟, 刘志红, 何沐全, 等. 成都市夏季近地面臭氧污染气象特征 [J]. 中国环境监测, 2018, 34(5): 36-45. XU K, LIU Z H, HE M Q, et al. Meteorological characteristics of O3 pollution near the ground in summer of Chengdu [J]. Environmental Monitoring in China, 2018, 34(5): 36-45(in Chinese).
[20] 张小娟, 李莉, 王红丽, 等. 2010—2016年上海城区臭氧长时间序列变化特征初探 [J]. 环境科学学报, 2019, 39(1): 86-94. ZHANG X J, LI L, WANG H L, et al. Preliminary study on the long-term trends of ozone in urban Shanghai from 2010 to 2016 [J]. Acta Scientiae Circumstantiae, 2019, 39(1): 86-94(in Chinese).
[21] 王旭东, 尹沙沙, 杨健, 等. 郑州市臭氧污染变化特征、气象影响及输送源分析 [J]. 环境科学, 2021, 42(2): 604-615. WANG X D, YIN S S, YANG J, et al. Characteristics, meteorological influences, and transport source of ozone pollution in Zhengzhou city [J]. Environmental Science, 2021, 42(2): 604-615(in Chinese).
[22] 赵伟, 高博, 卢清, 等. 2006—2019年珠三角地区臭氧污染趋势 [J]. 环境科学, 2021, 42(1): 97-105. ZHAO W, GAO B, LU Q, et al. Ozone pollution trend in the Pearl River Delta region during 2006-2019 [J]. Environmental Science, 2021, 42(1): 97-105(in Chinese).
[23] 海南省生态环境厅. 2019年海南省生态环境状况公报[OL]. [2020-06-05]. http://hnsthb.hainan.gov.cn/jdhy/zcjd/sptj/202006/t20200605_2799446_mo.html. [24] 符传博, 丹利, 唐家翔, 等. 2017年10月海南省一次臭氧污染特征及输送路径与潜在源区分析 [J]. 环境科学研究, 2021, 34(4): 863-871. doi: 10.13198/j.issn.1001-6929.2020.03.37 FU C B, DAN L, TANG J X, et al. Potential source contributions and transported routes in Hainan Province during ozone polluted episode in October 2017 [J]. Research of Environmental Sciences, 2021, 34(4): 863-871(in Chinese). doi: 10.13198/j.issn.1001-6929.2020.03.37
[25] 冯锦明, 赵天保, 张英娟. 基于台站降水资料对不同空间内插方法的比较 [J]. 气候与环境研究, 2004, 9(2): 261-277. doi: 10.3969/j.issn.1006-9585.2004.02.004 FENG J M, ZHAO T B, ZHANG Y J. Intercomparison of spatial interpolation basedon observed precipitation data [J]. Climatic and Environmental Research, 2004, 9(2): 261-277(in Chinese). doi: 10.3969/j.issn.1006-9585.2004.02.004
[26] 符传博, 吴涧, 丹利. 近50年云南省雨日及降水量的气候变化 [J]. 高原气象, 2011, 30(4): 1027-1033. FU C B, WU J, DAN L. Climatic changes of rainfall and rain days in Yunnan Province [J]. Plateau Meteorology, 2011, 30(4): 1027-1033(in Chinese).
[27] 符传博, 丹利, 吴涧, 等. 近46年西南地区晴天日照时数变化特征及其原因初探 [J]. 高原气象, 2013, 32(6): 1729-1738. doi: 10.7522/j.issn.1000-0534.2012.00162 FU C B, DAN L, WU J, et al. The regional and spatiotemporal characteristics of sunny sunshine duration in southwest China during recently 46 years and its formation reason [J]. Plateau Meteorology, 2013, 32(6): 1729-1738(in Chinese). doi: 10.7522/j.issn.1000-0534.2012.00162
[28] 魏凤英. 现代气候统计诊断与预测技术[M]. 2版. 北京: 气象出版社, 2007. WEI F Y. Climate statistical diagnosing and prediction[M]. 2nd ed. . Beijing: China Meteorological Press, 2007(in Chinese).
[29] 刘晶淼, 丁裕国, 黄永德, 等. 太阳紫外辐射强度与气象要素的相关分析 [J]. 高原气象, 2003, 22(1): 45-50. doi: 10.3321/j.issn:1000-0534.2003.01.006 LIU J M, DING Y G, HUANG Y D, et al. Correlation analyses between intensity of solar UltravioletRadiation and meteorological elements [J]. Plateau Meteorology, 2003, 22(1): 45-50(in Chinese). doi: 10.3321/j.issn:1000-0534.2003.01.006
[30] KAVASSALIS S C, MURPHY J G. Understanding ozone-meteorology correlations: A role for dry deposition [J]. Geophysical Research Letters, 2017, 44(6): 2922-2931. doi: 10.1002/2016GL071791 [31] ZHOU D R, DING A J, MAO H T, et al. Impacts of the East Asian monsoon on lower tropospheric ozone over coastal South China [J]. Environmental Research Letters, 2013, 8(4): 044011. doi: 10.1088/1748-9326/8/4/044011 [32] 王宇骏, 黄祖照, 张金谱, 等. 广州城区近地面层大气污染物垂直分布特征 [J]. 环境科学研究, 2016, 29(6): 800-809. doi: 10.13198/j.issn.1001-6929.2016.06.03 WANG Y J, HUANG Z Z, ZHANG J P, et al. Vertical distribution characteristics of air pollutants in the near-surface atmospheric layer in Guangzhou urban district [J]. Research of Environmental Sciences, 2016, 29(6): 800-809(in Chinese). doi: 10.13198/j.issn.1001-6929.2016.06.03
[33] TANG G Q, ZHU X W, XIN J Y, et al. Modelling study of boundary-layer ozone over Northern China - Part I: Ozone budget in summer [J]. Atmospheric Research, 2017, 187: 128-137. doi: 10.1016/j.atmosres.2016.10.017 [34] 王闯, 王帅, 杨碧波, 等. 气象条件对沈阳市环境空气臭氧浓度影响研究 [J]. 中国环境监测, 2015, 31(3): 32-37. doi: 10.3969/j.issn.1002-6002.2015.03.007 WANG C, WANG S, YANG B B, et al. Study of the effect of meteorological conditions on the ambient air ozone concentrations in Shenyang [J]. Environmental Monitoring in China, 2015, 31(3): 32-37(in Chinese). doi: 10.3969/j.issn.1002-6002.2015.03.007