ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-5-1039-2005 Validation of SCIAMACHY tropospheric NO<sub>2</sub>-columns with AMAXDOAS measurements Heue K.-P. 1 Richter A. 2 Bruns M. 2 Burrows J. P. 2 v. Friedeburg C. 1 Platt U. 1 Pundt I. 1 Wang P. 2 Wagner T. 1 Institut für Umweltphysik, Universität Heidelberg, INF 229, 69120 Heidelberg, Germany Institute of Environmental Physics, University of Bremen, P.O. 330440, 28334 Bremen, Germany 29 03 2005 5 4 1039 1051 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/5/1039/2005/acp-5-1039-2005.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/5/1039/2005/acp-5-1039-2005.pdf

Tropospheric NO<sub>2</sub> vertical and slant columns from the new satellite instrument SCIAMACHY on ENVISAT are validated by measurements of the <B>A</B>irborne <B>M</B>ulti <B>AX</B>is <B>DOAS</B> (AMAXDOAS) instrument on board the DLR&nbsp;Falcon. The results presented here were obtained in February 2003 on a flight over the Alps, the Po-Valley and the Mediterranean. The tropospheric vertical column measured by AMAXDOAS varied between 16.2 and 35.2*10<sup>15</sup>molec/cm<sup>2</sup> over the Po-Valley where SCIAMACHY data resulted in 19.9 to 37*10<sup>15</sup>molec/cm<sup>2</sup>. Over less polluted areas a similarly good agreement was found. The linear correlation between the two datasets results in a slope of 0.93. The slight differences observed can be attributed to the different spatial resolution and the temporal mismatch between the measurements over the Po-Valley.