Global distributions of C₂H₆, C₂H₂, HCN, and PAN retrieved from MIPAS reduced spectral resolution measurements

Abstract. Vertical profiles of mixing ratios of C₂H₆, C₂H₂, HCN, and PAN were retrieved from MIPAS reduced spectral resolution nominal mode limb emission measurements. The retrieval strategy follows that of the analysis of MIPAS high resolution measurements, with occasional adjustments to cope with the reduced spectral resolution under which MIPAS is operated since 2005. MIPAS measurements from January 2005 to January 2010 have been analyzed with special emphasis on October 2007. Largest mixing ratios are found in the troposphere, and reach 1.2 ppbv for C₂H₆, 1 ppbv for HCN, 600 pptv for PAN, and 450 pptv for C₂H₂. The estimated precisions in case of significantly enhanced mixing ratios (including measurement noise and propagation of uncertain parameters randomly varying in the time domain) and altitude resolution are typically 10%, 3–4.5 km for C₂H₆, 15%, 4–6 km for HCN, 6%, 2.5–3.5 km for PAN, and 7%, 2.5–4 km for C₂H₂.