Capability for ozone high-precision retrieval on JEM/SMILES observation Original Research Article

We estimate the capability of ozone (O3) retrieval with the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) instrument attached to the Exposed Facility of the Japanese Experiment Module (JEM) on the International Space Station (ISS). SMILES carries a 4-K mechanical refrigerator to cool superconducting devices in space. Since SMILES has high sensitivity thanks to the superconducting receiver, it is expected that SMILES has ability to retrieve O3 profiles more precisely than the previous millimeter–submillimeter limb measurements from satellites. We examine the random error and the systematic error of O3 vertical profiles based on the launch-ready retrieval algorithm developed for SMILES. The best random error with single-scan spectra is 0.4% at an altitude of 30 km with 3 km vertical resolution in the mid-latitudes. The random error is better than 5% in the altitude region from 15 to 70 km in the nighttime and from 15 to 55 km in the daytime with 3 km vertical resolution in the mid-latitudes. By averaging ten profiles, the random error is improved to 1% at 70 km altitude in the nighttime and to 5% in the daytime. Using SMILES, we expect to determine the diurnal variation of O3 vertical profiles with high precision in the upper stratosphere. Finally, the retrieval capability of O3 in the lower stratosphere is estimated. When retrieving spectral data using two receiver bands (624.32–626.32 GHz and 649.12–650.32 GHz) the random error above 13 km in the mid-latitudes and above 15 km in the tropics is expected to be better than 5% under clear sky conditions.