摘要
基于天津市 2022 年夏季污染物监测数据和气象资料讨论臭氧(O3)污染状况,采用主观天气分型方法对同期天气型进行分类对比,分析天气型对 O3 浓度的影响,并利用后向轨迹追踪方法探讨主要天气型下 O3 污染特点及变化规律.结果表明:天津市地面为低压系统控制、高空受西南和偏南气流影响时,易出现 O3 污染,此天气型下气温较高,风力较小,外来输送叠加本地生成,颗粒物吸湿增长,出现 O3 和 PM2.5 协同污染;天津市地面为均压系统控制、高空受辐合气流影响时,污染主要来自本地生成,O3 和 PM2.5 浓度高值较低、污染过程持续时间较短;天津市地面为高压系统控制、高空受偏北气流影响时,高浓度 O3 不易出现.在污染排放相对稳定的前提下,天气型变化是影响 O3 浓度高低的主要原因.
Abstract
Based on the pollutant monitoring data and meteorological data of Tianjin in summer 2022,the O3 pollution status was discussed.The subjective weather classification method was used to classify and compare the weather types in the same period,and the influence of weather types on O3 concentration was analyzed.The characteristics and variations of O3 pollution under major weather types were explored by using the backward trajectory tracking method.The results showed that O3 pollution was prone to occur in Tianjin when the surface was controlled by low pressure system and the high altitude was affected by southwest and south airflow.The temperature was high and the wind was low under this weather type.When moisture absorption growth of particulate matter,synergistic pollution of O3 and PM2.5 would caused by external transport and local generation.When the surface was controlled by pressure balanced system and the high altitude was affected by convergent airflow,the high concentrations of O3 and PM2.5 were low and the duration of the pollution process was short due to the pollution was mainly generated locally.High concentrations of O3 was not easy to appear when the surface was controlled by high pressure system and the high altitude was affected by north airflow.Under the premise of relatively stable pollution emission,the change of weather types was the main reason affected the O3 concentration.
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万方数据