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Validation of MIPAS ClONO2 measurements
1Institut für Meteorologie und Klimaforschung, Forschungszentrum Karlsruhe, Germany
2Instituto de Astrofísica de Andalucía, Granada, Spain
3Department of Chemistry, University of Waterloo, Ontario, Canada
4Harvard-Smithsonian Center for Astrophysics, Atomic and Molecular Physics Division, Cambridge, MA, USA
5Atmospheric Chemistry Division, National Center for Atmospheric Research, Boulder, CO, USA
6Department of Chemistry, University of Wollongong, Australia
7Harvard-Smithsonian Center for Astrophysics, Optical and Infrared Astronomy Division, Cambridge, MA, USA
8Institut d’Astrophysique et de Géophysique, Université de Liège, Belgium
9Department of Radio and Space Science, Chalmers University of Technology, G¨oteborg, Sweden
10Institut für Umweltphysik, Universität Bremen, Germany
11Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
12National Institute of Water and Atmospheric Research, Lauder, New-Zealand
Abstract. Altitude profiles of ClONO2 retrieved with the IMK (Institut für Meteorologie und Klimaforschung) science-oriented data processor from MIPAS/Envisat (Michelson Interferometer for Passive Atmospheric Sounding on Envisat) mid-infrared limb emission measurements between July 2002 and March 2004 have been validated by comparison with balloon-borne (Mark IV, FIRS2, MIPAS-B), airborne (MIPAS-STR), ground-based (Spitsbergen, Thule, Kiruna, Harestua, Jungfraujoch, Izaña, Wollongong, Lauder), and spaceborne (ACE-FTS) observations. With few exceptions we found very good agreement between these instruments and MIPAS with no evidence for any bias in most cases and altitude regions. For balloon-borne measurements typical absolute mean differences are below 0.05 ppbv over the whole altitude range from 10 to 39 km. In case of ACE-FTS observations mean differences are below 0.03 ppbv for observations below 26 km. Above this altitude the comparison with ACE-FTS is affected by the photochemically induced diurnal variation of ClONO2. Correction for this by use of a chemical transport model led to an overcompensation of the photochemical effect by up to 0.1 ppbv at altitudes of 30–35 km in case of MIPAS-ACE-FTS comparisons while for the balloon-borne observations no such inconsistency has been detected. The comparison of MIPAS derived total column amounts with ground-based observations revealed no significant bias in the MIPAS data. Mean differences between MIPAS and FTIR column abundances are 0.11±0.12×1014 cm−2 (1.0±1.1%) and −0.09±0.19×1014 cm−2 (−0.8±1.7%), depending on the coincidence criterion applied. χ2 tests have been performed to assess the combined precision estimates of MIPAS and the related instruments. When no exact coincidences were available as in case of MIPAS – FTIR or MIPAS – ACE-FTS comparisons it has been necessary to take into consideration a coincidence error term to account for χ2 deviations. From the resulting χ2 profiles there is no evidence for a systematic over/underestimation of the MIPAS random error analysis.
Discussion Paper (PDF, 1077 KB) Interactive Discussion (Closed, 2 Comments) Final Revised Paper (ACP)
Citation: Höpfner, M., von Clarmann, T., Fischer, H., Funke, B., Glatthor, N., Grabowski, U., Kellmann, S., Kiefer, M., Linden, A., Milz, M., Steck, T., Stiller, G. P., Bernath, P., Blom, C. E., Blumenstock, Th., Boone, C., Chance, K., Coffey, M. T., Friedl-Vallon, F., Griffith, D., Hannigan, J. W., Hase, F., Jones, N., Jucks, K. W., Keim, C., Kleinert, A., Kouker, W., Liu, G. Y., Mahieu, E., Mellqvist, J., Mikuteit, S., Notholt, J., Oelhaf, H., Piesch, C., Reddmann, T., Ruhnke, R., Schneider, M., Strandberg, A., Toon, G., Walker, K. A., Warneke, T., Wetzel, G., Wood, S., and Zander, R.: Validation of MIPAS ClONO2 measurements, Atmos. Chem. Phys. Discuss., 6, 9765-9821, 2006. Bibtex EndNote Reference Manager
