The modification of ultraviolet Total Ozone Unit (TOU) for absorbing aerosol index

Aerosol Absorbing Index (AAI) can be used for the observation of the absorbing aerosol including dust, biomass burning and volcano ash etc. Recently, with much more aerosol pollution events occurring, atmospheric environment is getting worse in China. The AAI derived from FY-3/TOU has been used for the atmospheric aerosol pollution observation since 2013 by China Meteorological Administration. In this paper, the precision factors analysis of AAI retrieval from TOU is made. Based on the analysis, the wavelengths most suitable for AAI retrieval are 354 nm and 388 nm. Besides, considering the low spatial resolution of TOU (50×50 km2), a modified UV sensor is proposed with characters of much smaller size, higher sensitivity (SNR<4000) and higher spatial resolution (<5 km) which is much more suitable for observing aerosol pollution events, especially in urban areas.