. 2016 Sep 29;6:34408. doi: 10.1038/srep34408

Table 1. Tropospheric NO₂ mean VCDs (in units of 10¹⁵ molecules cm⁻²) at Beijing urban area in different time periods.

Time period	MAX-DOAS	NASA-OMI	USTC-OMI
pre-Parade	22.07	9.18	11.65
Parade	12.50	3.81	6.21
post-Parade	25.00	14.24	19.44
pre-APEC	39.01	14.87	17.20
APEC	30.72	9.88	10.66
post-APEC	48.76	31.48	31.43

Table 1. Tropospheric NO2 mean VCDs (in units of 1015 molecules cm−2) at Beijing urban area in different time periods.