Study on O₃ Variations in Nanjing and the Surrounding Source Analysis

Table 1

Pollution air mass tracks in spring, summer, autumn, and winter.

Season	Track	Track direction	Airflow trajectories area	Probability (%)	Distance (km)
Spring	Track 1	North	Weifang, Rizhao, Lianyungang, Suqian, Huaian, and east of Chuzhou	27.28	550
	Track 2	Southeast	Shanghai, Suzhou, Wuxi, Changzhou, and Zhenjiang	46.04	350
	Track 3	Southwest	North of Anqing, Hefei, and Ma’anshan	26.68	300
Summer	Track 1	Southeast	Shanghai, Suzhou, Wuxi, Changzhou, and Zhenjiang	58.52	350
	Track 2	Northwest	Zaozhuang, Xuzhou, Suzhou, Bengbu, and Chuzhou	9.18	380
	Track 3	Southeast-eastward	Central Yellow sea, Nantong, Taizhou, and Zhenjiang	10.27	750
	Track 4	Southwest	Border of Anqing and Jiujiang, Tonglin, Wuhu, and Ma’anshan	22.04	400
Autumn	Track 1	Northwest	Kaifeng, Shangqiu, Haozhou, Bengbu, and Chuzhou	25.32	500
	Track 2	Northeast	North of Yellow sea, Yancheng, and Yangzhou	39.74	300
	Track 3	Southeast	Border of Yellow sea and east China sea, Shanghai, Suzhou, Wuxi, and Zhenjiang	34.94	400
Winter	Track 1	North	Langfang, Cangzhou, Binzhou, Weifang, east of Linyi, Liangyungang, Huaian, and east of Chuzhou	11.45	800
	Track 2	Northeast-eastward	Central Yellow sea, North of Nantong, Taizhou, and Zhenjiang	49.88	350
	Track 3	West	Border of Chuzhou and Hefei	38.67	100