Table 1.
Mean O3 contribution from different source regions during Phase Ⅰ and Ⅱ (%). (QHD: Qinghuangdao, JZ: Jinzhou, YK: Yingkou, DL: Dalian, BTH: Beijing–Tianjin–Hebei region).
| Period | City | BTH | Northeast China | Japan | Shandong | Korean Peninsula | Nei Mongol | Ocean | Background |
|---|---|---|---|---|---|---|---|---|---|
| Phase Ⅰ | QHD | 28.0 | 2.6 | 0.8 | 31.1 | 0.6 | 1.7 | 5.4 | 29.9 |
| JZ | 18.4 | 12.8 | 0.8 | 23.8 | 0.7 | 3.0 | 7.1 | 33.4 | |
| YK | 15.0 | 17.0 | 0.9 | 20.2 | 0.7 | 3.0 | 6.5 | 36.7 | |
| DL | 8.5 | 9.7 | 1.0 | 34.9 | 0.8 | 2.1 | 11.3 | 31.8 | |
| Average | 17.5 | 10.5 | 0.9 | 27.5 | 0.7 | 2.5 | 7.6 | 33.0 | |
| Phase Ⅱ | QHD | 10.2 | 3.7 | 1.2 | 35.8 | 7.7 | 2.7 | 10.2 | 28.5 |
| JZ | 7.3 | 7.2 | 1.4 | 28.9 | 8.7 | 3.6 | 11.0 | 31.9 | |
| YK | 6.8 | 9.4 | 1.6 | 25.2 | 11.3 | 3.6 | 13.2 | 29.0 | |
| DL | 4.7 | 9.2 | 1.8 | 14.4 | 15.2 | 4.2 | 20.5 | 30.1 | |
| Average | 7.3 | 7.4 | 1.5 | 26.1 | 10.7 | 3.5 | 13.7 | 29.9 |