The Aerosol Index (AI) is a well-established data product that has been calculated for several different satellite instruments spanning a period of more than 30 years. The S5-P/TROPOMI aerosol index is referred to as the UVAI. The relatively simple calculation of the Aerosol Index is based on wavelength dependent changes in Rayleigh scattering in the UV spectral range where ozone absorption is very small. For a given wavelength pair a ratio is calculated from measured top of the atmosphere (TOA) reflectance and pre-calculated theoretical reflectance for a Rayleigh scattering-only atmosphere and results in a residual value. Positive values of this residual indicate the presence of UV-absorbing aerosol. like dust and smoke. Clouds yield near-zero residual values and negative residual values can be indicative of the presence of scattering aerosols. Unlike satellite-based aerosol optical thickness measurements, UVAI can also be calculated in the presence of clouds so that daily, global coverage is possible. This is ideal for tracking the evolution of episodic aerosol plumes from dust outbreaks, volcanic ash, and biomass burning.
USER DOCUMENTATION: ATBD
The Algorithm Theoretical Basis Document (ATBD) can be found by clicking here.
PUM & SAMPLE DATA
The Product User Manuals (PUM) and Sample Data Files are being updated based on a new release of the processing software and will be available for download by mid-May 2017.
After launch, preliminary product results will be provided during the Commissioning Phase and the Operational Phase.