Comparison of SMILES ClO profiles with satellite, balloon-borne and ground-based measurements
Journal article, 2013

We evaluate the quality of ClO profiles derived from the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the International Space Station (ISS). Version 2.1.5 of the level-2 product generated by the National Institute of Information and Communications Technology (NICT) is the subject of this study. Based on sensitivity studies, the systematic error was estimated as 5–10 pptv at the pressure range of 80–20 hPa, 35 pptv at the ClO peak altitude (~ 4 hPa), and 5–10 pptv at pressures ≤ 0.5 hPa for daytime mid-latitude conditions. For nighttime measurements, a systematic error of 8 pptv was estimated for the ClO peak altitude (~ 2 hPa). The SMILES NICT v2.1.5 ClO profiles agree with those derived from another level-2 processor developed by the Japan Aerospace Exploration Agency (JAXA) within the bias uncertainties, except for the nighttime measurements in the low and middle latitude regions where the SMILES NICT v2.1.5 profiles have a negative bias of ~ 30 pptv in the lower stratosphere. This bias is considered to be due to the use of a limited spectral bandwidth in the retrieval process of SMILES NICT v2.1.5, which makes it difficult to distinguish between the weak ClO signal and wing contributions of spectral features outside the bandwidth. In the middle and upper stratosphere outside the polar regions, no significant systematic bias was found for the SMILES NICT ClO profile with respect to data sets from other instruments such as the Aura Microwave Limb Sounder (MLS), the Odin Sub-Millimetre Radiometer (SMR), the Envisat Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), and the ground-based radiometer at Mauna Kea, which demonstrates the scientific usability of the SMILES ClO data including the diurnal variations. Inside the chlorine-activated polar vortex, the SMILES NICT v2.1.5 ClO profiles show larger volume mixing ratios by 0.4 ppbv (30%) at 50 hPa compared to those of the JAXA processed profiles. This discrepancy is also considered to be an effect of the limited spectral bandwidth in the retrieval processing. We also compared the SMILES NICT ClO profiles of chlorine-activated polar vortex conditions with those measured by the balloon-borne instruments: Terahertz and submillimeter Limb Sounder (TELIS) and the MIPAS-balloon instrument (MIPAS-B). In conclusion, the SMILES NICT v2.1.5 ClO data can be used at pressures ≤ ~30 hPa for scientific analysis.

Author

H. Sagawa

Japan National Institute of Information and Communications Technology

T. O. Sato

Japan National Institute of Information and Communications Technology

Tokyo Institute of Technology

P. Baron

Japan National Institute of Information and Communications Technology

E. Dupuy

Japan National Institute of Information and Communications Technology

National Institute for Environmental Studies of Japan

N. Livesey

Jet Propulsion Laboratory, California Institute of Technology

Joachim Urban

Chalmers, Earth and Space Sciences, Global Environmental Measurements and Modelling

T. von Clarmann

Karlsruhe Institute of Technology (KIT)

A. de Lange

Netherlands Institute for Space Research (SRON)

G. Wetzel

Karlsruhe Institute of Technology (KIT)

B. J. Connor

BC Consulting

A. Kagawa

Japan National Institute of Information and Communications Technology

Donal Murtagh

Chalmers, Earth and Space Sciences, Global Environmental Measurements and Modelling

Y. Kasai

Tokyo Institute of Technology

Japan National Institute of Information and Communications Technology

Atmospheric Measurement Techniques

1867-1381 (ISSN) 1867-8548 (eISSN)

Vol. 6 12 3325-3347

Subject Categories

Meteorology and Atmospheric Sciences

Earth and Related Environmental Sciences

DOI

10.5194/amt-6-3325-2013

More information

Latest update

4/30/2018