Figure 7: NO₂ plumes above China by GOME-2 sensor of MetOp-A satellite, October, 2010. Concentrations vary from 0−10×10¹⁵ molecules of NO₂ per cm² (clear to concentrated brown color).
Source: http://www.nnvl.noaa.gov/MediaDetail.php?MediaID=577&MediaTypeID=1