Table 1.
Mean and standard deviation (SD) of the six criteria air pollutants (μg m−3), main PM2.5 chemical species including water-soluble ions (μg m−3), trace elements (ng m−3), carbonaceous components (μg m−3), and meteorological parameters including ambient temperature (Temp, °C), atmospheric pressure (P, hPa), wind speed (WS, m s−1), relative humidity (RH, %), mixing layer height (MLH, m), and solar irradiation (SI, W m−2) for the one-month lockdown period of Wuhan in 2020 and the same period in 2019.
| Variables | 2019 |
2020 |
Variables | 2019 |
2020 |
|---|---|---|---|---|---|
| Mean ± SD | Mean ± SD | Mean ± SD | Mean ± SD | ||
| CO | 1.02 ± 0.37 | 0.98 ± 0.31 | Fe | 292 ± 235 | 153 ± 135 |
| NO2 | 40.7 ± 28.6 | 18.1 ± 15.6 | Cu | 26.6 ± 28.3 | 11.1 ± 6.48 |
| O3 | 29.7 ± 21.1 | 40.9 ± 18.0 | Zn | 90.2 ± 70.7 | 32.5 ± 24.2 |
| PM10 | 76.0 ± 42.4 | 50.4 ± 28.0 | As | 11.8 ± 10.9 | 4.99 ± 4.87 |
| PM2.5 | 72.9 ± 35.4 | 45.9 ± 26.9 | Se | 5.00 ± 3.16 | 2.36 ± 2.12 |
| SO2 | 6.15 ± 6.10 | 4.52 ± 3.30 | Ag | 5.80 ± 2.54 | 3.62 ± 2.07 |
| Na+ | 0.21 ± 0.17 | 0.24 ± 0.08 | Cd | 4.11 ± 2.12 | 4.47 ± 2.25 |
| NH+4 | 14.4 ± 6.65 | 9.59 ± 6.06 | Ba | 78.7 ± 128 | 36.0 ± 55.7 |
| Mg2+ | 0.21 ± 0.26 | 0.01 ± 0.01 | Hg | 1.95 ± 0.80 | 1.13 ± 0.87 |
| K+ | 2.02 ± 2.13 | 1.22 ± 1.11 | Pb | 47.7 ± 36.8 | 17.3 ± 12.1 |
| Ca2+ | 0.48 ± 0.39 | 0.08 ± 0.10 | OC | 10.4 ± 4.21 | 8.09 ± 3.52 |
| Cl− | 2.82 ± 1.85 | 1.96 ± 1.62 | EC | 2.19 ± 1.23 | 1.15 ± 0.70 |
| NO-3 | 23.9 ± 12.3 | 14.1 ± 9.49 | Temp | 4.12 ± 3.51 | 8.97 ± 3.90 |
| SO2–4 | 13.4 ± 6.40 | 10.3 ± 6.48 | P | 1023 ± 5.34 | 1019 ± 5.12 |
| K | 2038 ± 2026 | 1163 ± 1053 | WS | 2.08 ± 1.53 | 0.99 ± 0.79 |
| Ca | 173 ± 222 | 105 ± 104 | RH | 84.3 ± 15.1 | 73.2 ± 19.3 |
| Cr | 2.73 ± 2.44 | 1.28 ± 1.81 | MLHa | 318 ± 232 | 415 ± 381 |
| Mn | 23.3 ± 19.3 | 8.17 ± 5.78 | SIa | 126 ± 140 | 195 ± 180 |
a
MLH and SI were derived from the HYSPLIT calculation.