GOME & SCIAMACHY Absorbing Aerosol Index

The Absorbing Aerosol Index (AAI) is a differential spectral index to identify the presence of elevated UV-absorbing aerosols in the Earth's atmosphere. The aerosol types that are mostly seen in the AAI are desert dust and biomass burning aerosols. The AAI works equally well over land and sea surfaces and also in the presence of clouds. The AAIs provided here are derived from the reflectances measured by GOME 1 and 2 and SCIAMACHY at 340 and 380 nm.

Example result / latest result


Satellite: ESR-2, ENVISAT, MetOp-A, MetOp-B
Instrument(s): GOME-1, SCIAMACHY, GOME-2
Instrument/algorithm PI: M. de Graaf, L. G. Tilstra (KNMI)
Contact details: graafdem[at]knmi.nl, tilstra[at]knmi.nl
Parameter(s): AAI
Aerosol algorithm: SC-AAI
Cloud screening: n/a
Aerosol model: 340/380 nm index
Retrieval assumptions: constant surface albedo at index range
Retrieval limitations: High solar zenith angle (>85 deg), sunglint areas (flagged)
Spatial, temporal coverage:

GOME-1: 1995-2003, global; SCIAMACHY 2002-2012, global; GOME-2 (MetOp-A): 2010 – present, global; GOME-2 (MetOp-B): 2012 – present, global

Spatial, temporal resolution:

GOME-1: 960 km swath, 320 x 40 km2 (lv2); SCIAMACHY: 960 km swath, 60 x 30 km2 (lv2); GOME-2: 960 km swath, 80 x 40 km2 (lv2); GOME-1&2, SCIAMACHY: 1x1.25 degree (lv3 gridded)

Operations status:

GOME-2: operational / reprocessing; SCIAMACHY: reprocessing

Validation status: TOMS AAI intercomparison
Quality control: degradation monitoring
last algorithm version: GOME-1: v5.0 (05/2011), SCIAMACHY: 5.1 (06/2012)
last validation: 2012