基于TROPOMI的扬州市对流层甲醛和二氧化氮时空分布特征分析

以2020年1月—2021年9月对流层观测仪（TROPOMI）卫星观测资料反演获取的对流层甲醛（HCHO）、二氧化氮（NO₂）柱浓度数据为依据，采用统计方法分析了扬州市HCHO和NO₂柱浓度的时空分布特征。结果表明，扬州市对流层HCHO、NO₂平均柱浓度分别为903.01×10¹³， 633.77×10¹³mole/cm²；受太阳紫外辐射影响，HCHO柱浓度变化特征表现为6月最高、1月最低；受气象条件和人为排放强度影响，NO₂则表现为1月最高、8月最低。2021年1—9月扬州市对流层HCHO、NO₂柱浓度月均值同比2020年分别增长4.0%，40.6%。空间分布特征显示，扬州市对流层HCHO和NO₂浓度高值区主要分布在扬州市南部，且浓度高值区域与重点排污企业分布情况较为一致，多为电力供热、工业锅炉、冶金、石化与化工、表面涂层等行业。相关性分析显示，对流层HCHO与气温、臭氧浓度呈显著正相关，而NO₂与气温、臭氧浓度呈显著负相关。

Analysis of Temporal and Spatial Variation Characteristics of Formaldehyde and Nitrogen Dioxide in Troposphere in Yangzhou City Based on TROPOMI

Based on the tropospheric formaldehyde (HCHO) and nitrogen dioxide (NO₂) column concentration data obtained from TROPOMI satellite observation data from January 2020 to September 2021, the spatial and temporal distribution characteristics of HCHO and NO₂column concentration in Yangzhou were analyzed. The results showed that the average column concentrations of HCHO and NO₂in troposphere were 903.01×10¹³and 633.77×10¹³ mole/cm², respectively. Under the influence of solar ultraviolet radiation, the monthly mean column concentration of HCHO was the highest in June and the lowest in January. Influenced by meteorological conditions and anthropogenic emission intensity, NO₂was the highest in January and the lowest in August. The spatial distribution characteristics show that the high concentration areas of tropospheric HCHO and NO₂ in Yangzhou are mainly distributed in the south of Yangzhou, and the distribution of high concentration areas is consistent with that of key pollutant discharge enterprises, mostly electric heating, industrial boiler, metallurgy, petrochemical and chemical industry, surface coating and other industries. Correlation analysis showed that tropospheric HCHO was positively correlated with air temperature and ozone concentration, while NO₂was negatively correlated with air temperature and ozone concentration.