基于多源遥感与后向轨迹的雅安市2023年典型臭氧污染成因分析

Analysis on the Causes of Typical Ozone Pollution in Ya'an City in 2023 based on Multi Source Remote Sensing and Backward Trajectory

2023年4月雅安市发生较为严重的春季O_(3)污染,研究雅安市臭氧污染的现状及成因对于降低污染对当地人民健康和生态环境造成的危害、推动社会可持续发展具有重要意义。以2023年4月雅安市的两次典型O_(3)污染过程为例,基于多源遥感的地表温度、地表太阳入射辐射、O_(3)及其前体物(NO_(2)和CH_(2)O)产品,结合本地高程、植被覆盖度、土地利用类型、环境站点监测资料和气象再分析资料,采用地学数理统计(相关系数r)和后向轨迹分析的方法,探究太阳辐射、地表温度和O_(3)前体物等要素对O_(3)污染的影响机制。结果表明:(1)两次污染过程O_(3)浓度变化呈现明显“单峰型”的周期性变化,峰值在13:00-19:00。(2)平均太阳辐射大于900 W/m^(2)、平均地表温度大于18℃是雅安地区发生O_(3)污染的阈值条件。(3)雅安地区天然源前体物排放对O_(3)生成的贡献不可忽略,O_(3)前体物的光化学反应主要受太阳辐射影响(|r|>0.5),而最终的O_(3)浓度则主要受温度影响(|r|>0.6)。(4)成都市的蒲江县,眉山市的洪雅县、丹棱县和东坡区是雅安市O_(3)污染的主要贡献区域。

Under the background of serious spring ozone pollution in Ya'an in April 2023,it is of great significance to study the current situation and causes of ozone pollution in Ya'an to reduce the harm of pollution to local people's health and ecological environment and promote sustainable social development.Taking the two typical ozone pollution processes in Ya'an City in April 2023 as an example,this study uses geomathematical statistics(correlation coefficient r)and backward trajectory analysis methods to explore the impact mechanism of solar radiation,land surface temperature,and ozone precursors on ozone pollution,basing on multi-source remote sensing of Land Surface Temperature,Surface Solar Irradiance(SSI),ozone and its precursors(nitrogen dioxide,formaldehyde)products,combined with local elevation,vegetation coverage,land use type,environmental site monitoring data,and meteorological reanalysis data.The results show that:(1)The changes in ozone concentration during the two pollution processes exhibit a significant"single peak"periodic change,with a peak from 13:00 to 19:00.(2)The threshold conditions for ozone pollution in Ya'an area are average solar radiation greater than 900 W/m^(2)and average land surface temperature greater than 18℃.(3)The contribution of natural source precursor emissions to ozone generation in the Ya'an area cannot be ignored.The photochemical reaction of ozone precursors is mainly affected by solar radiation(|r|>0.5),while the final O_(3)(The chemical formula of ozone)concentration is mainly affected by temperature(|r|>0.6).(4)Pujiang County in Chengdu,Hongya County,Danling County and Dongpo District in Meishan City are the main contributing areas of ozone pollution in Ya'an City.