研究报告
祁宏,张小玲,康平,Klaus Schaefer,向卫国,邓中慈,卢宁生,雷雨.COVID-19疫情期间成都市地面臭氧污染特征及气象成因分析[J].环境科学学报,2021,41(10):4200-4211
COVID-19疫情期间成都市地面臭氧污染特征及气象成因分析
- Analysis of characteristics and meteorological causes of surface ozone pollution in Chengdu during the COVID-19 epidemic
- 基金项目:国家重点研发计划课题(No.2018YFC0214002,2016YFA0602004);四川省科技计划项目(No.2018JY0011,2018SZDZX0023);成都市科技计划项目(No.2019-YF05-00718-SN)
- 祁宏
- 成都信息工程大学大气科学学院, 高原大气与环境四川省重点实验室, 成都 610225
- 张小玲
- 1. 成都信息工程大学大气科学学院, 高原大气与环境四川省重点实验室, 成都 610225;2. 成都平原城市气象与环境四川省野外科学观测研究站, 成都 610225
- 康平
- 1. 成都信息工程大学大气科学学院, 高原大气与环境四川省重点实验室, 成都 610225;2. 成都平原城市气象与环境四川省野外科学观测研究站, 成都 610225
- Klaus Schaefer
- 1. 成都信息工程大学大气科学学院, 高原大气与环境四川省重点实验室, 成都 610225;2. 成都平原城市气象与环境四川省野外科学观测研究站, 成都 610225
- 向卫国
- 成都信息工程大学大气科学学院, 高原大气与环境四川省重点实验室, 成都 610225
- 邓中慈
- 成都信息工程大学大气科学学院, 高原大气与环境四川省重点实验室, 成都 610225
- 卢宁生
- 成都信息工程大学大气科学学院, 高原大气与环境四川省重点实验室, 成都 610225
- 雷雨
- 成都信息工程大学大气科学学院, 高原大气与环境四川省重点实验室, 成都 610225
- 摘要:受COVID-19疫情影响,我国各地采取了一系列封锁管控措施,由此导致大气污染物排放强度降低.本文以成都市为例,分析了2020年上半年的气象条件和大气污染浓度特征,并重点对臭氧浓度变化及同期对比结果进行了细致分析.结果表明:①与2019年同期相比,除O3外的5种污染物(NO2、CO、SO2、PM10、PM2.5)浓度均降低,降幅分别为13.60%、8.96%、6.30%、4.56%、1.80%,而O3浓度却异常升高,升幅最大值分别出现在2月(35.1%)和5月(36.1%).②2020年上半年,O3浓度高值出现时间较2015—2019年提前,气象条件较有利于臭氧的生成.100 hPa和500 hPa位势高度为正距平,气温、日照时数较往年升高,相对湿度和降水量下降,以静小风为主.③2020年4月25日—5月6日臭氧污染持续时间长,主要是由于复工复产导致臭氧前体物排放增加,以及稳定的天气形势,使成都长时间处于高温(>30℃)、低湿(40%~60%)、静小风(1.3 m·s-1)等不利扩散的气象条件下.气团后向轨迹和污染潜在源区表明研究区受到来自成都偏东一带及川南地区高污染气团短距离输送的影响.
- Abstract:Affected by the COVID-19 epidemic, a series of lockdown control measures adopted by various regions have reduced the emission intensity of air pollutants. Taking Chengdu as an example, this study analyzed the meteorological conditions and pollution concentration characteristics in the first half of 2020 and focused on a detailed analysis of variations in ozone (O3) concentration. The results showed that:①Compared with 2019, except for O3, all five pollutants in Chengdu showed a decreased trend, and the concentrations of NO2, CO, SO2, PM10 and PM2.5 decreased by 13.60%, 8.96%, 6.30%, 4.56%, 1.80%, respectively. On the contrary, O3 concentration increased abnormally, with the largest increase in February (35.1%) and May (36.1%). ②During the first half of 2020, the high O3 concentration level appeared earlier than in previous years (2015-2019). Meteorological conditions were more supportive to the generation of O3 also. The geopotential heights of 100 hPa and 500 hPa showed positive anomalies, the temperature and sunshine duration was higher than in previous years, and the relative humidity as well as precipitation were lower with a quiet breeze. ③The O3 formation process lasted a long time from April 25th to May 6th, mainly due to the increased emissions of O3 precursors during this period and the relatively stable weather situation, which kept the Chengdu area exposed to unfavorable weather conditions of high temperature (average temperature>30℃), low humidity (40%~60%), and quiet breeze (1.3 m·s-1) for a long time. The backward trajectories and potential sources of air pollution showed that the air quality was affected by the short-distance transportation of high-polluted air masses from the East of Chengdu and southern Sichuan.