Absorbing Aerosol Index
As additional service to interpret the SO2 vertical column densities, the web pages that show images of the SO2 data also show an image
of the Absorbing Aerosol Index (AAI) for the same region, taken from the same
The AAI indicates the presence of elevated absorbing aerosols in the Earth's atmosphere. The aerosol types that are mostly seen in the AAI are desert dust and biomass burning aerosols, but in case of volcano eruption, AAI can also be a good indicator of the location of ashes. The AAIs provided here are derived from the reflectances measured by OMI at 354 and 388 nm, and from the reflectances measured by SCIAMACHY and GOME-2 at 340 and 380 nm.
Image of the AAI by SCIAMACHY (top) and OMI (bottom) intruments the 19 April 2010 after the eruption of the Eyjafjöll volcano.