2019年9月佛山一次臭氧污染过程输送路径分析

Route Analysis of an Ozone Pollution Process in Foshan in September 2019

采用佛山大气环境超级观测站大气污染物监测数据以及相关气象观测资料,结合WRF-FLEXPART模型,分析2019年9月佛山市1次O_(3)污染过程的污染特征和输送路径。结果表明:佛山市9月26日~10月5日的O_(3)污染过程主要受副热带高压控制和台风“米娜”影响,发生中度污染4天、轻度污染6天,26~29日O_(3)及其前体物(NO_(x)和VOCs)浓度均较高。每天12:00~18:00 O_(3)浓度较高,在O_(3)高浓度时段存在风场辐合。WRF-FLEXPART的后向24 h计算结果表明,9月26日~9月30日的大气污染物的输送主要来自测点的东北方,10月1日~10月5日主要来自测点的西南方。潜在源区包括佛山市南海区狮山、西樵、丹灶、里水、九江北部,禅城区南庄北部,三水区白坭、乐平东南部、芦苞东南部,高明区荷城、杨和、明城东北部以及广州市西北部和江门市北部等地。

Using the monitoring data of atmospheric pollutants and meteorological observation data from Foshan super observatory of atmospheric environment,WRF-FLEXPART model was used to analysis the pollution characteristics and transport path of an ozone pollution process in Foshan in September 2019.The results show that ozone pollution process in Foshan from September 26 to October 5 was mainly influenced by subtropical high pressure and typhoon“Mina”.Four day’s mild pollution and six day’s moderate pollution occured during the study period.O_(3)and its precursors(NO_(x) and VOCs)were both at higher concentrations from 26 to 29.Daily variation of O_(3)concentration was higher between 12:00 and 18:00 with wind convergence.The 24 h back trajectories of air masses were calculated by WRF-FLEXPART,which showed that the transport path was mainly from the northeast of the monitoring site from 26 to 30 September and from southwest from 1 to 5 October.Shishan,Xiqiao,Danzao,Lishui and northern Jiujiang in Nanhai District,northern Nanzhuang in Chancheng District,Baini,southeastern Leping and southeastern Lubao in Sanshui District,northeastern Hecheng,Yanghe and northeastern Mingcheng in Gaoming District,Foshan City,as well as northwestern Guangzhou City and northern Jiangmen City were the main potential contribution region for this pollution episode.