气象条件对珠三角秋季地表臭氧年变化及趋势的影响

Meteorological Influences on Annual Variation and Trend of Autumn Surface Ozone in the Pearl River Delta

基于2015~2022年珠三角O_(3)监测数据以及再分析气象资料,利用多元线性回归(MLR)和LMG方法量化了气象条件对臭氧(O_(3))日最大8 h浓度平均值(MDA8-O_(3))年变化和趋势的影响.结果表明,基于关键气象参数建立的MLR模型性能良好,同时基于秋季各月参数建立的MLR模型模拟的MDA8-O_(3)变化会比基于整个秋季气象参数建立的MLR模型更准确.总云量、相对湿度、2m最高温度和850 h Pa经向风的共同作用导致了2020年MDA8-O_(3)相对于2019年减少了34.1μg·m^(-3),贡献率分别为31.3%、45.2%、15.8%和6.7%.珠三角2015~2022年的9月、10月、11月和秋季观测的MDA8-O_(3)变化率分别为7.3、5.2、4.8和5.8μg·(m^(3)·a)^(-1),其中由气象驱动的趋势分别为3.6、2.4、2.4和3.1μg·(m^(3)·a)^(-1),整体而言,气象条件对2015~2022年珠三角秋季MAD8-O3变化的贡献率为53.4%.

Based on the ozone(O_(3))monitoring data of the Pearl River Delta(PRD)from 2015 to 2022 and the reanalysis of meteorological data,the impact of meteorological conditions on the annual variation and trends of the maximum daily 8-hour average O_(3) concentration(MDA8-O_(3))were quantified using multiple linear regression(MLR)and LMG methods.The results indicated that the MLR model constructed using meteorological parameters from individual months in autumn better simulated the variation in MDA8-O_(3) compared to that in the model built using meteorological parameters from the entire autumn season.The combined influence of total cloud cover,relative humidity,2 m maximum temperature,and 850 hPa zonal wind led to a reduction of 34.1μg·m^(−3) in MAD8-O_(3) in 2020 compared to that in 2019,with contributions of 31.3%,45.2%,15.8%,and 6.7%,respectively.The observed trends of MDA8-O_(3) in the PRD for September,October,November,and the autumn season during 2015-2022 were 7.3,5.2,4.8,and 5.8μg·(m^(3)·a)^(-1),respectively.Among these,the trends driven by meteorological factors were 3.6,2.4,2.4,and 3.1μg·(m^(3)·a)^(-1).Overall,meteorological conditions contributed 53.4%to the variations in autumn MDA8-O_(3) in the PRD from 2015 to 2022.