气象因素对成都中心城区近地面臭氧的影响

Effects of Meteorological Factors on Near-surface Ozone in Central Chengdu

文章对2019年成都市中心城区大气臭氧自动连续监测数据及同步气象数据进行研究分析,结果表明成都臭氧浓度呈现春、夏>秋、冬的特点,由以8月浓度最高。日变化呈现"单峰型",早上08:00-09:00出现最低值,下午浓度较高,峰值浓度出现在16:00-17:00。O3浓度与气温、边界层、风速呈正相关,与相对湿度、降水量呈负相关。当成都中心城区O3浓度出现超标时,气温变化范围为28.537.1℃,相对湿度变化范围为34%63.6%,风速变化范围为0.52.5 m/s,边界层高度的范围为7701967 m,主要为无降水天气和偏南风控制。气流以短距离传输即局地传输为主导,受本地污染源影响明显,导致成都O3浓度较高的气流主要来自其东北和偏南方向,受达州、德阳、绵阳、资阳和眉山等城市影响较大。

The automatic continuous monitoring data and synchronous meteorological data of atmospheric ozone in Chengdu central city in 2019 were studied and analyzed,and the results showed that the ozone concentration in Chengdu was higher in spring and summer than in autumn and winter,with the highest concentration in August.The diurnal variation showed a"unimodal pattern",with the lowest value occurring from 08:00 to 09:00 in the morning,and a higher concentration in the afternoon,with the peak concentration occurring from 16:00 to 17:00.O3 concentration is positively correlated with temperature,boundary layer and wind speed,and negatively correlated with relative humidity and precipitation.When the O3 concentration in the downtown area of chengdu exceeds the standard,the temperature changes range from 28.5℃to 37.1℃,the relative humidity changes range from 34%to 63.6%,the wind speed changes range from 0.5 to 2.5 m/s,and the BLH changes range from 770 to 1967 m,mainly due to non-precipitation weather and southerly risk control system.Chengdu area is dominated by short-distance transmission,namely local transmission,and is significantly affected by local pollution sources.The airflow with high O3 concentration in Chengdu mainly comes from its northeast and south directions,and is greatly affected by Dazhou,Deyang,Mianyang,Ziyang and Meishan.