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the period division rule for remotely sensed NO2 concentration in 2019 and 2020.
| Period | 2019 | 2020 |
|---|---|---|
| P1 (14 days before Chinese New Year) | 19.01.22–19.01.28 | 20.01.11–20.01.17 |
| P2 (7 days before Chinese New Year) | 19.01.29–19.02.04 | 20.01.18–20.01.24 |
| P3 (Chinese New Year) | 19.02.05–19.02.11 | 20.01.25–20.01.31 |
| P4 (7 days after Chinese New Year) | 19.02.12–19.02.18 | 20.02.01–20.02.07 |
| P5 (14 days after Chinese New Year) | 19.02.19–19.02.25 | 20.02.08–20.02.14 |
