Stratospheric NO2 from SCIAMACHY limb and nadir measurements - validation of the ESA operational data products
Azam, Faiza; Weigel, Katja; Rozanov, Alexei; Weber, Mark; Bovensmann, Heinrich; Burrows, J. P.
Institute of Environmental Physics (IUP), University of Bremen, GERMANY

From 2002 to 2012, the SCanning Imaging Absorption spectroMeter for Atmospheric CHartograpY (SCIAMACHY), aboard Envisat, observed the transmitted, scattered and reflected solar radiation from the Earth's atmosphere in different observation geometries. Monitoring the stability and verifying the quality of the decadal timescale data products is a prerequisite to their usage for long term trend analysis and process studies. With this perspective, the ESA project SCILOV-10 (SCIAMACHY long term validation 2010) aims at lifetime validations and documentation of the quality of selected operational data products retrieved from SCIAMACHY in limb and nadir geometries. The limb observations provide vertically resolved profiles and the nadir measurements give vertical column amounts, both, on global scale. Here we focus on NO₂ which plays an important role in stratospheric ozone chemistry by controlling ozone abundances through catalytic destruction or by mitigating ozone depletion through reservoir formation. We present the long term comparisons of the operational stratospheric NO₂ limb and nadir products with corresponding scientific SCIAMACHY retrievals at the Institute of Environmental Physics (IUP) Bremen and to other satellite measurements, e.g ACE-FTS, HALOE, SAGE-II, OSIRIS in case of limb comparisons and GOME and GOME2 for nadir comparisons.