Institute for environmental physics / University Bremen World Meteorological Organization

Spectral aerosol optical thickness is retrieved simultaneously with the determination of spectral ground reflectance by the Bremen AErosol Retrieval (Baer). The retrieval of AOT provides for 7 short-wave channels of the MERIS instrument the spectral behaviour of AOT, which is used for the determination of the spectral slope in terms of the Angstrom -parameter. Angstrom is obtained using AOT, retrieved from the 7 MERIS channels with wavelength 0.665 µm.

Satellite ENVISAT (ESA)
Instrument(s) MERIS
Contact details vountas[at]
Parameter(s) Spectral AOT, Angstrom exponent
Aerosol algorithm BEAR
Cloud screening

ESA L2 MERIS cloud screening

Aerosol model LACE-98
Retrieval assumptions surface reflectance from vegetation cover and model reflectance spectra, AOT from LUT
Retrieval limitations no TIR channels for cloud screening on MERIS
Spatial, temporal coverage 2005/2006, Germany / SAMUM campaign (Morocco)
Spatial, temporal resolution 1km / 1150km swath / 35 days repeat cycle
Operations status experimental
Validation status  
Quality control  
last algorithm version  
last validation  


Algorithm description Product format description
Version explanation Validation summary


Product data access
Image / quicklook data access