MIPAS-STR measurements in the arctic UTLS in winter/spring 2010: instrument characterization, retrieval and validation

• Published in: Atmospheric Measurement Techniques
• Main Authors: Woiwode, W., Oelhaf, H., Gulde, T., Piesch, C., Maucher, C., Ebersoldt, A., Keim, C., Höpfner, M., Khaykin, S., Ravegnani, F., Ulanovsky, A.E., Volk, C.M., Hösen, E., Dörnbrack, A., Ungermann, J., Kalicinsky, C., Orphal, J.
• Format: Other Non-Article Part of Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2012
• Subjects: Wolkenphysik und Verkehrsmeteorologie; Arctic
• Online Access: https://elib.dlr.de/72085/; https://elib.dlr.de/72085/1/amt-5-1205-2012.pdf; http://www.atmos-meas-tech.net/5/1205/2012/

The mid-infrared FTIR-limb-sounder Michelson Interferometer for Passive Atmospheric Sounding � STRatospheric aircraft (MIPAS-STR) was deployed onboard the stratospheric aircraft M55 Geophysica during the RECONCILE campaign in the arctic winter/spring 2010. From the MIPAS-STR measurements, vertical profiles and 2-dimensional vertical cross-sections of temperature and trace gases are retrieved. Detailed mesoscale structures of polar vortex air, extra vortex air and vortex filaments are identified in the results at a typical vertical resolution of 1 to 2 km and typical horizontal sampling density of 45 or 25 km, depending on the sampling programme. Results are shown for the RECONCILE flight 11 on 2 March 2010 and are validated with collocated in-situ measurements of temperature, O3, CFC-11, CFC-12 and H2O. Exceptional agreement is found for the in-situ comparisons of temperature and O3, with mean differences (vertical profile/along flight track) of 0.2/�0.2 K for temperature and �0.01/0.05 ppmv for O3 and corresponding sample standard deviations of the mean differences of 0.7/0.6 K and 0.1/0.3 ppmv. The comparison of the retrieved vertical cross-sections of HNO3 from MIPAS-STR and the infrared limb-sounder Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere � New Frontiers (CRISTA-NF) indicates comprehensive agreement. We discuss MIPAS-STR in its current configuration, the spectral and radiometric calibration of the measurements and the retrieval of atmospheric parameters from the spectra. The MIPAS-STR measurements are significantly affected by continuum-like contributions, which are attributed to background aerosol and broad spectral signatures from interfering trace gases and are important for mid-infrared limb-sounding measurements in the Upper Troposphere/Lower Stratosphere (UTLS) region. Considering for continuum-like effects, we present a scheme suitable for accurate retrievals of temperature and an extended set of trace gases, including the correction of a systematic line-of-sight offset.