Advanced MIPAS-Level-2 Data Analysis (AMIL2DA)

Abstract

The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), which is a core instrument of the Envisat polar platform launched on 1 March 2002 by the European Space Agency (ESA), is a powerful tool to measure vertical profiles of trace species on a global scale. While operational data processing by ESA covers only analysis of pressure, temperature, and the mixing ratios of the species O3, H2O, HNO3, CH4, and N2O, MIPAS infrared spectral limb emission measurements contain much more information not explored in by real time processing. The goal of AMIL2DA is to generate and validate data analysis tools for these supplemental data products. Instead of merging the contributions of all participants to one data analysis algorithm which fits all purposes, the AMIL2DA strategy is to maintain the diversity of different computer codes by each group which are custom-tailored to their specific scientific needs, and prove their reliability by thorough cross-validation. As a first step, forward radiative transfer algorithms, which are the core part of each data processor, have been cross-validated. In a second step, the inversion underwent a blind-test intercomparison based on synthe tic measurements. In the third step, the codes have been applied to real MIPAS measurements. Deficiencies in forward radiative transfer as well as inversion algorithms have been detected and removed. Along with these activities, the spectroscopic database was improved and contributions to the MIPAS instrument characterization were made.