Meteorological and urban landscape factors on severe air pollution in Beijing

Figures & data

Table 1. Standard of each pollutant for calculating individual air quality (I_i)

	Standard of each pollutant
Ii	SO2 (μg/m^3)	NO2 (μg/m^3)	PM10 (μg/m^3)	CO (mg/m^3)	O3 (μg/m^3)	PM2.5 (μg/m^3)
0	0	0	0	0	0	0
50	50	40	50	2	100	35
100	150	80	150	4	160	75
150	475	180	250	14	215	115
200	800	280	350	24	265	150
300	1600	565	420	36	800	250
400	2100	750	500	48	—*	350
500	2620	940	600	60	—*	500

*The P_i for O₃ is not calculated when O₃ is larger than 800 μg/m³.

Figure 1. Air quality of Beijing in January 2013 with space views of nonpolluted (2013.01.03) and polluted (2013.01.12) days.

Figure 2. Linkage of visibility with wind speed and AQI.

Figure 3. Air quality index (AQI) and primary pollutant of Beijing in January 2013.

Figure 4. Frequency of wind direction with maximum and extreme wind speed at Beijing in January 2013.

Figure 5. Relation between fraction of impervious surface and air quality index (AQI) within the 6th Ring Road of Beijing during the severe polluted days (AQI > 300).