Table 1.
Summary of gas, meteorological, and light absorption data during winter 2020.
| Before level 1a | Level 1c | Level 2b | Level 3d | Overall | |
|---|---|---|---|---|---|
| SO2 (ppb) | 1.5 ± 1.2 | 1.2 ± 1.9 | 3.2 ± 3.1 | 2.4 ± 1.5 | 1.8 ± 1.6 |
| NO (ppb) | 9.6 ± 8.8 | 2.5 ± 2.2 | 6.0 ± 5.3 | 8.8 ± 6.6 | 5.4 ± 3.3 |
| NO2 (ppb) | 7.6 ± 6.4 | 5.3 ± 3.5 | 12.7 ± 11.1 | 14.4 ± 11.9 | 9.3 ± 4.6 |
| NOx (ppb) | 17.2 ± 12.1 | 7.8 ± 5.9 | 18.7 ± 8.8 | 23.2 ± 21.4 | 14.5 ± 12.1 |
| O3 (ppb) | 10.1 ± 8.1 | 15.1 ± 14.5 | 23.2 ± 15.7 | 15.8 ± 14.3 | 16.0 ± 12.9 |
| PM10 (μg m−3) | 72.2 ± 41.0 | 48.3 ± 22.5 | 75.7 ± 61.4 | 46.7 ± 41.9 | 54.1 ± 42.6 |
| PM2.5 (μg m−3) | 53.2 ± 21.9 | 35.9 ± 31.0 | 40.7 ± 40.5 | 24.6 ± 21.1 | 35.5 ± 23.2 |
| BC (μg m−3) | 5.1 ± 2.2 | 3.3 ± 1.7 | 4.2 ± 3.4 | 2.9 ± 1.9 | 3.8 ± 3.0 |
| CO (ppb) | 600.1 ± 176.4 | 594.0 ± 150.8 | 698.0 ± 105.8 | 638.9 ± 221.9 | 616.7 ± 261.1 |
| babs, 370 (M m−1) | 150.2 ± 71.9 | 114.6 ± 81.7 | 116.2 ± 21.3 | 73.0 ± 51.5 | 113.3 ± 31.4 |
| babs, 880 (M m−1) | 35.8 ± 34.1 | 22.1 ± 11.0 | 27.7 ± 21.6 | 19.4 ± 21.7 | 23.0 ± 23.3 |
| babs,370, BC (M m−1) | 75.3 ± 27.6 | 52.3 ± 24.0 | 65.2 ± 24.5 | 37.4 ± 29.8 | 57.5 ± 27.1 |
| babs,370, BrC (M m−1) | 73.9 ± 39.2 | 61.9 ± 61.6 | 48.5 ± 30.3 | 19.3 ± 18.7 | 50.9 ± 54.7 |
| AAE 370–880 | 2.0 ± 0.4 | 2.0 ± 0.5 | 1.8 ± 0.3 | 1.6 ± 0.1 | 1.9 ± 0.3 |
The values are mean ± standard deviation. The AE33-measured BC can be defined as equivalent BC (eBC) unless otherwise stated (Petzold et al., 2013). The selected wavelengths for BC were typical among BC studies using aethalometers (Harrison et al., 2013; Wang et al., 2011; Zhu et al., 2017).
a
From January 17th to January 24th.
b
From January 25th to March 15th.
c
From March 15th to March 24th.
d
From March 24th to April 1st.