Analysis of Meteorological Conditions Causing Ozone Pollution in Southern Jiangsu

Huang Wenyan; Lei Zhengcui; He Tao; Yao Li'na; Wu Jianqiu

doi:10.16765/j.cnki.1673-7148.2025.06.007

Abstract：Using the ozone data of five national control points in southern Jiangsu Province from 2019 to 2021,the observation data of national meteorological stations in the same period and the ERA5 reanalysis data,this article analyzes the spatio-temporal distribution characteristics of ozone pollution in southern Jiangsu and its relationship with relevant meteorological elements,and,meanwhile,classifies the weather conditions causing ozone pollution.The results show that the diurnal variation difference of ozone concentration among five cities of southern Jiangsu mainly occurs in the daytime,and the annual ozone concentration distribution has two peaks.When the temperature is 30-35℃,the sunshine time exceeds 10 hours,the relative humidity is 30%-60%,the wind speed is 1-3 m/s and the wind direction is prevailing southerly,the ozone excess pollution rate can reach its maximum value.The over-standard ozone pollution rate in Suzhou is significantly lower than that in the other four cities.When analyzing the excessive ozone pollution in the entire area of southern Jiangsu,except for Suzhou,60%of the backward trajectory in the Suzhou area mainly passes through the ocean to the east.In addition,the higher total cloud cover and lower total radiation in Suzhou are not conducive to the formation of ozone through photo-chemical reactions.There are three major types of synoptic situation for ozone pollution in southern Jiangsu,namely,the northwest airflow behind the trough pattern(69%),the short wave trough pattern(17%)and the subtropical high control pattern(14%).The main transmission paths in the backward trajectory of Nanjing and Suzhou under the control of the northwest airflow behind the trough are the northeast trans-port from the Yangtze River area in Anhui Province and the northwest transport from the vicinity of Hang-zhou Bay,respectively.