Trend Studies of Ozone Depleting Substances Derived from the new MIPAS ESA V7 Products

Abstract

MIPAS on ENVISAT performed almost continuous measurements of atmospheric composition for approximately 10 years, from June 2002 to April 2012. During this period the first effects of the reduction in the emissions of CFCs following the ratification of the Montreal protocol in 1987 can be observed. Even if ten years is a short period to derive statistically robust trends, it has been shown that useful information on long-term variation of atmospheric constituents can be derived from the analysis of MIPAS measurements. Previous versions of MIPAS dataset were affected by an instrumental drift caused by the ageing of the detectors that introduced a non negligible systematic error in the trend estimation. The latest full mission reprocessed dataset V7 uses the L1 spectra that have been corrected for the drift of the non-linearity response of the detectors. Furthermore, the L2 processor has been upgraded with new functionalities that improve the quality of the retrieved products. We present here the results of the trend studies from the analysis of the new MIPAS V7 products with particular emphasis on ozone-depleting species: CFC-11, CFC-12, CCl4 and HCFC-22.