European Geosciences Union, Atmospheric Chemistry and Physics, 2(9), p. 413-442, 2009
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The ENVISAT validation programme for the atmospheric instruments MIPAS, SCIAMACHY and GOMOS is based on a number of balloon-borne, aircraft, satellite and ground-based correlative measurements. In particular the activities of validation scientists were coordinated by ESA within the ENVISAT Stratospheric Aircraft and Balloon Campaign or ESABC. As part of a series of similar papers on other species [this issue] and in parallel to the contribution of the individual validation teams, the present paper provides a synthesis of comparisons performed between MIPAS CH 4 and N 2 O profiles produced by the current ESA operational software (Instrument Processing Facility version 4.61 or IPF v4.61, full resolution MIPAS data covering the period 9 July 2002 to 26 March 2004) and correlative measurements obtained from balloon and aircraft experiments as well as from satellite sensors or from ground-based instruments. In the middle stratosphere, no significant bias is observed between MIPAS and correlative measurements, and MIPAS is providing a very consistent and global picture of the distribution of CH 4 and N 2 O in this region. In average, the MIPAS CH 4 values show a small positive bias in the lower stratosphere of about 5%. A similar situation is observed for N 2 O with a positive bias of 4%. In the lower stratosphere/upper troposphere (UT/LS) the individual used MIPAS data version 4.61 still exhibits some unphysical oscillations in individual CH 4 and N 2 O profiles caused by the processing algorithm (with almost no regularization). Taking these problems into account, the MIPAS CH 4 and N 2 O profiles are behaving as expected from the internal error estimation of IPF v4.61 and the estimated errors of the correlative measurements.