NO₂ Retrieved by SCIAMACHY Across Stratospheric Transport Barriers in Comparison With the General Circulation Model EMAC
Pukite, Janis¹; Kühl, Sven¹; Dörner, Steffen¹; Jöckel, Patrick²; Wagner, Thomas^1
1Max Planck Institute for Chemistry, GERMANY; ²Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, GERMANY

The Scanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) on the ENVISAT satellite probed the atmosphere at the day side of Earth in alternating sequences of nadir and limb measurements from 2002 to April 2012. Limb measurements performed at different tangent heights contain information about profiles of various trace gases in the stratosphere with poor horizontal resolution. The retrieval of horizontally resolved vertical profiles of stratospheric trace gases is performed by Differential Optical Absorption Spectroscopy (DOAS) followed by a tomographic inversion approach. The tomographic approach, involving either only limb or even additionally nadir measurements, minimizes errors caused by the horizontal inhomogeneity especially around transport barriers. We study the performance of the tomographic retrieval of NO₂ profiles across the regions of stratospheric transport barriers by comparing it with modelling results from the atmospheric general circulation model EMAC. Here we concentrate on seasonal, multiannual (QBO), altitudinal and longitudinal variability of the location and strength of the tropical stratospheric transport barriers. Also a comparison with measurements performed by other satellite instruments (MLS, MIPAS) is shown.