[Measurement of atmosphere NO2 amounts and angle spacial distribution using zenith-light spectra and sky-light...

A novel approach to retrieving atmosphere NO2 slant column density is described, in which the sunlight scattered in the zenith direction and the skylight are used as the light sources. The slant column density of the same azimuth but different obliquities, which are between 0.5 x 10(16) and 11 x 10(16) molecule x cm(-2), with the angle from 85 degrees to 10 degrees, as well as that of the same obliquity but different azimuths, which are between 10(16) and 10(17) molecule cm(-2), were calculated. The study indicates that the results have good correlation with real atmosphere status. The angle spatial distribution could be embodied by the difference of NO2 slant column density in different azimuths and obliquities. The reference spectrum and sample spectrum were collected with the same instrument at the same time, so the measurement accuracy has been improved. This method favored not only real-time monitoring NO2 content of space arbitrary direction, especially near the ground NO2 pollution emergencies, but also overcast and rainy areas where it is very difficult to collect good direct solar spectrum.