Articles | Volume 6, issue 9
Atmos. Meas. Tech., 6, 2311–2338, 2013

Special issue: Changes in the vertical distribution of ozone – the SI2N report...

Atmos. Meas. Tech., 6, 2311–2338, 2013

Research article 10 Sep 2013

Research article | 10 Sep 2013

Validation of stratospheric and mesospheric ozone observed by SMILES from International Space Station

Y. Kasai1,2, H. Sagawa1, D. Kreyling1, E. Dupuy1,3, P. Baron1, J. Mendrok1,4, K. Suzuki1,5, T. O. Sato1,2, T. Nishibori1,6, S. Mizobuchi6, K. Kikuchi1, T. Manabe7, H. Ozeki8, T. Sugita4, M. Fujiwara9, Y. Irimajiri1, K. A. Walker10,11, P. F. Bernath12, C. Boone11, G. Stiller13, T. von Clarmann13, J. Orphal13, J. Urban14, D. Murtagh14, E. J. Llewellyn15, D. Degenstein15, A. E. Bourassa15, N. D. Lloyd15, L. Froidevaux16, M. Birk17, G. Wagner17, F. Schreier17, J. Xu17, P. Vogt17, T. Trautmann17, and M. Yasui1 Y. Kasai et al.
  • 1National Institute of Information and Communications Technology (NICT), Koganei, Tokyo, Japan
  • 2Tokyo Institute of Technology, Yokohama, Kanagawa, Japan
  • 3National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan
  • 4Luleå University of Technology, Kiruna, Sweden
  • 5The University of Tokyo, Graduate School of Arts and Sciences, Meguro, Tokyo, Japan
  • 6Japan Aerospace Exploration Agency (JAXA), Tsukuba, Japan
  • 7Osaka Prefecture University, Naka, Sakai, Osaka, Japan
  • 8Toho University, Funabashi, Chiba, Japan
  • 9Hokkaido University, Kita, Sapporo, Japan
  • 10University of Toronto, Toronto, Ontario, Canada
  • 11University of Waterloo, Waterloo, Ontario, Canada
  • 12Old Dominion University, Norfolk, Virginia, USA
  • 13Institute for Meteorology and Climate Research (IMK), Karlsruhe Institute of Technology, Karlsruhe, Germany
  • 14Chalmers University of Technology, Göteborg, Sweden
  • 15Institute of Space and Atmospheric Studies, University of Saskatchewan, Saskatoon, Canada
  • 16Jet Propulsion Laboratory (JPL), California Institute of Technology, Pasadena, California, USA
  • 17German Aerospace Center (DLR), Remote Sensing Technology Institute, Oberpfaffenhofen, Weßling, Germany

Abstract. We observed ozone (O3) in the vertical region between 250 and 0.0005 hPa (~ 12–96 km) using the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the Japanese Experiment Module (JEM) of the International Space Station (ISS) between 12 October 2009 and 21 April 2010. The new 4 K superconducting heterodyne receiver technology of SMILES allowed us to obtain a one order of magnitude better signal-to-noise ratio for the O3 line observation compared to past spaceborne microwave instruments. The non-sun-synchronous orbit of the ISS allowed us to observe O3 at various local times. We assessed the quality of the vertical profiles of O3 in the 100–0.001 hPa (~ 16–90 km) region for the SMILES NICT Level 2 product version 2.1.5. The evaluation is based on four components: error analysis; internal comparisons of observations targeting three different instrumental setups for the same O3 625.371 GHz transition; internal comparisons of two different retrieval algorithms; and external comparisons for various local times with ozonesonde, satellite and balloon observations (ENVISAT/MIPAS, SCISAT/ACE-FTS, Odin/OSIRIS, Odin/SMR, Aura/MLS, TELIS). SMILES O3 data have an estimated absolute accuracy of better than 0.3 ppmv (3%) with a vertical resolution of 3–4 km over the 60 to 8 hPa range. The random error for a single measurement is better than the estimated systematic error, being less than 1, 2, and 7%, in the 40–1, 80–0.1, and 100–0.004 hPa pressure regions, respectively. SMILES O3 abundance was 10–20% lower than all other satellite measurements at 8–0.1 hPa due to an error arising from uncertainties of the tangent point information and the gain calibration for the intensity of the spectrum. SMILES O3 from observation frequency Band-B had better accuracy than that from Band-A. A two month period is required to accumulate measurements covering 24 h in local time of O3 profile. However such a dataset can also contain variation due to dynamical, seasonal, and latitudinal effects.