豫北“盆地”型城市臭氧污染日变化特征及污染过程分析——以林州市为例

Analysis of diurnal variation and pollution process of Ozone pollution in"basin"cities in Northern Henan Province:a case study of Linzhou City

基于2021年林州市O_(3)监测数据和相关资料,分析了林州市的O_(3)污染日变化特征及典型污染过程。结果表明,2021年林州市O_(3)污染天共79天,占全年污染总天数的56%,制约着林州市空气质量改善。O_(3)污染天主要发生在4-9月,O_(3)浓度日变化在5:00-9:00相对较低,在13:00-19:00处于高值时段。O_(3)污染日可分为典型单峰型、双峰型、多峰型、夜间降幅小型4种类型。单峰型主要受高温、低湿、弱风等气象条件以及本地排放污染光化学生成影响较大;双峰、多峰型除了本地污染排放光化学生成影响外,外来传输对其多峰的发展影响较大;夜间降幅小型可能与区域输送以及本地独特的局地环流形势有关。对林州一次高浓度O_(3)污染过程分析发现,上风向地区污染输送可加重林州市O_(3)污染程度。

Based on the O_(3)monitoring data and related data in Linzhou City in 2021,the diurnal variation characteristics and typical pollution processes of O_(3)pollution in Linzhou City were analyzed.The results show that there are 79 O_(3)polluted days in 2021,accounting for 56%of the total annual pollution days,which restricts the improvement of air quality in Linzhou.The O_(3)pollution days mainly occur from April to September.The daily variation of O_(3)concentration is relatively low at 5:00-9:00 and high at 13:00-19:00.O_(3)pollution days can be divided into four types:typical single peak type,double peak type,multi-peak type and small decrease at night.Single-peak type is mainly affected by favourable weather such as high temperature,low humidity,weak wind and photochemical formation due to local emission.Except for photochemical formation due to local emission,extraneous transport has a greater impact on the peak deveopment for bimodal and multi-peak type,and the small decrease at night may be related to regional transport and unique local circulation.The analysis of a high concentration O_(3)pollution process in Linzhou shows that pollution transport from upwind area can aggravate O_(3)pollution in Linzhou.