利用经验正交函数分解方法分析广州臭氧污染特征

EOF Analysis of Ozone Concentration in Guangzhou

广州市空气污染治理重点逐渐转向臭氧污染治理,理清臭氧污染特征是制定治理措施的基础。文章利用经验正交函数分解方法对2016-2018年广州市51个监测点的臭氧逐时浓度进行分解。分解得到的51个模态的解释方差均较小,反映出臭氧污染特征的复杂性。该文只分析头3大模态,累积解释方差贡献率32.7%。第一模态显示市区及南部地区臭氧为负距平值区,北部地区为正距平值区,反映的是臭氧和二氧化氮的"跷跷板"关系;第二模态显示广州南部为正距平值区,北部为负距平值区,中部为过渡区,反映的是南北地区受太阳辐射不同所导致的臭氧浓度差异;第三模态的时间系数存在明显的日变化和季节变化,空间分布反映的是城乡差异,反映的是城市热岛效应对臭氧浓度的影响。

Mitigation of ozone pollution in Guangzhou is becoming an important task in Guangzhou,China.EOF decomposition method was used to decompose the ozone time-to-time concentrations at 51 monitoring points in Guangzhou from 2016 to 2018,and the explained variance of the 51 modes obtained by decomposition is relatively small,reflecting the complexity of ozone pollution characteristics.The top three major modes contribute 32.7%of cumulative explanatory variance.The first mode represented the teetertotter relationship between O3 and NO2;the second mode showed the difference of concentration of O3 between Guangzhou south and north districts,causing by the different incoming solar radiation,and the third mode were implying the urban heat island and its effect on O3.