Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) - 05.20.15

Overview | Description | Applications | Operations | Results | Publications | Imagery

ISS Science for Everyone

Science Objectives for Everyone
The Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) investigation aims to globally map stratospheric trace gases by means of the most sensitive submillimeter receiver. Although SMILES stopped atmospheric observation due to instrumental failures since April 2010, highly sensitive data obtained for a half year provides accurate global datasets of atmospheric minor constituents related to ozone chemistry. SMILES continues operations for instrumental calibration and cooling of a mechanical cooler, as well as a brush-up of retrieval algorithms for atmospheric constituents.
Science Results for Everyone
This investigation takes precise measurements of daily constituents in lowest layer of Earth’s atmosphere to help evaluate accuracy of climate models. Data show that daily variation in partial Ice Water Path (pIWP) of ice clouds is strong over land, peaking between late afternoon and early evening, but relatively weak over oceans with peaks at noon and early morning. Further, data show that daily cloud ice mass cycles are complex. Measurement of ozone distribution and short-lived trace atmosphere compounds that can destroy ozone showed ozone loss at different altitudes during Arctic winter. These observations provide a better understanding of the processes controlling stratospheric ozone chemistry and those related to climate change.

The following content was provided by Masato Shiotani, and is maintained in a database by the ISS Program Science Office.
Information provided courtesy of the Japan Aerospace and Exploration Agency (JAXA).
Experiment Details


Principal Investigator(s)
Masato Shiotani, Kyoto University, Uji, Japan

Masahiro Takayanagi, Japan Aerospace and Exploration Agency, Sagamihara, Japan

Japan Aerospace Exploration Agency (JAXA), Tsukuba, Japan

Sponsoring Space Agency
Japan Aerospace Exploration Agency (JAXA)

Sponsoring Organization
Information Pending

Research Benefits
Earth Benefits, Scientific Discovery

ISS Expedition Duration
March 2009 - September 2014

Expeditions Assigned

Previous ISS Missions

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Experiment Description

Research Overview

  • The main scientific target of the SMILES mission is to evaluate quantitatively the recovery and stability of the stratospheric ozone layer. There are still considerable uncertainties in factors affecting ozone levels. There is a need for a detailed understanding of ozone chemistry based on a high sensitive observation.
  • SMILES has a high potential to observe atmospheric minor constituents which contribute the ozone depletion in the middle atmosphere.
  • SMILES provides accurate global datasets of ozone-depletion gas concentrations and gives important insights into the ozone trend, especially chlorine and bromine compounds related to ozone chemistry.

SMILES (Superconducting Submillimeter-Wave Limb-Emission Sounder) is a sensitive submillimeter-wave sounder. The objective of SMILES is to monitor global distributions of the stratshperic trace gases which contribute ozone depletion. SMILES is the first to use a superconductive low-noise receiver with a mechanical 4-K refrigerator in space to realize a high sensitive observation.

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Space Applications
The technologies of the cryogenic system used in SMILES may be applied to future spacecraft development.

Earth Applications
The high-sensitivity observations of SMILES improve scientific understanding of processes controlling the stratospheric ozone chemistry and those related to climate change.

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Operational Requirements
SMILES requires cooling operation and instrumental calibration operation. For the cooling operation, low-rate downlink is used. The operation is scheduled four times in 2011, each takes a few weeks to complete. After 2011, a weeklong simplified cooling operation is conducted at annual intervals. For the instrumental calibration operation, both low- and medium-rate downlink are used.

Operational Protocols
For the cooling operation, two mechanical cryocoolers are operated. Operation procedures aim to achieve a cryogenic temperature of about 4 Kelvin. For the instrumental calibration operation, subsystems related to a signal chain are powered on. The internal calibration signals are generated to investigate the response of the subsystems.

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Results/More Information

The Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) attached to the International Space Station provides scientists with an opportunity to investigate atmospheric phenomena in the stratosphere and the mesosphere in unprecedented detail and serves as a valuable tool to evaluate the accuracy of climate models. Water vapor, clouds, and cloud ice mass in the lowest layer in the Earth’s atmosphere-the troposphere-where all weather take place, play an important role in Earth’s climate, but knowledge of them, in particular the daily (diurnal) variation, is limited. SMILES data show that the diurnal cycle of upper tropospheric ice clouds has a clear land–ocean contrast. Over land, the diurnal variation of partial Ice Water Path (pIWP) is strong and its maximum occurs between late afternoon and early evening. Over ocean, the diurnal variation of oceanic pIWP is relatively weak and has two peaks with one at noon and one in the early morning. SMILES data demonstrate that the diurnal cycles of cloud ice mass are complex.


SMILES also measured ozone in the stratosphere with high precision. Ozone plays a major role in controlling Earth’s exposure to space radiation and shielding us from solar ultraviolet rays, so it is crucial to make accurate measurements of ozone global distribution and yearly changes. The comparisons of SMILES data with other sources show good agreement of stratospheric ozone in the mesosphere, the agreement is also good even at a high altitude of 45 miles (73 km). However, SMILES data quality is poor below 11 miles (18 km), especially at lower latitudes. It is observed that a negative bias, particularly in the lower stratosphere at equatorial latitudes, exists with SMILES data. Researchers suggest this is from a time lag in measurements and a correction method would be appropriate to improve results in this region. Also, accurate temperature measurements for the whole middle atmosphere combined with use of the chemistry-transport model, may be able to provide realistic assessments of the space-time variations of ozone.


Data from SMILES over the same period show ozone losses at different altitudes inside the polar vortex for the Arctic winter. Reactions of trace short-lived atmospheric compounds, such as chlorine monoxide radical (ClO), hydroxyl radical (HO2), hydrochloric acid (HCl) and Hypochlorous acid (HOCl) with solar radiation can destroy ozone. SMILES measured these chemical species in the middle atmosphere and gave the first global observations of the diurnal variation of HOCl in the upper atmosphere. SMILES data are consistent with results from a laboratory experiment and calculations for similar low-pressure conditions. These results offer the opportunity to study the reaction ClO+HO2!HOCl+O2 in the lower mesosphere, useful for assessing the performance of latest chemistry–climate models (CCM).

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Results Publications

    Sato TO, Mizoguchi A, Mendrok J, Kanamori H, Kasai Y.  Measurement of the pressure broadening coefficient of the 625GHz transition of in the sub-millimeter-wave region. Journal of Quantitative Spectroscopy and Radiative Transfer. 2010 April; 111(6): 821-825. DOI: 10.1016/j.jqsrt.2009.11.022.

    Kuribayashi K, Sagawa H, Lehmann R, Sato TO, Kasai Y.  Direct estimation of the rate constant of the reaction ClO + HO2 → HOCl + O2 from SMILES atmospheric observations. Atmospheric Chemistry and Physics. 2014 January 9; 14(1): 255-266. DOI: 10.5194/acp-14-255-2014.

    Khosravi M, Baron P, Urban J, Froidevaux L, Jonsson AI, Kasai Y, Kuribayashi K, Mitsuda C, Murtagh DP, Sagawa H, Santee ML, Sato TO, Shiotani M, Suzuki M, von Clarmann T, Walker KA, Wang S.  Diurnal variation of stratospheric and lower mesospheric HOCl, ClO and HO<sub>2</sub> at the equator: comparison of 1-D model calculations with measurements by satellite instruments. Atmospheric Chemistry and Physics. 2013 August 6; 13(15): 7587-7606. DOI: 10.5194/acp-13-7587-2013.

    Sato TO, Sagawa H, Yoshida N, Kasai Y.  Vertical profile of δ18OOO from the middle stratosphere to lower mesosphere from SMILES spectra. Atmospheric Measurement Techniques. 2014 April 10; 7(4): 941-958. DOI: 10.5194/amt-7-941-2014.

    Sagi K, Murtagh DP, Urban J, Sagawa H, Kasai Y.  The use of SMILES data to study ozone loss in the Arctic winter 2009/2010 and comparison with Odin/SMR data using assimilation techniques. Atmospheric Chemistry and Physics. 2014 December 8; 14(13): 12855-12869. DOI: 10.5194/acp-14-12855-2014.

    Ochiai S, Kikuchi K, Nishibori T, Manabe T, Ozeki H, Mizukoshi K, Ohtsubo F, Tsubosaka K, Irimajiri Y, Sato R, Shiotani M.  Performance of JEM/SMILES in orbit. 21st International Symposium on Space Terahertz Technology, Oxford, UK; 2010 March 23-25 179-184.

    Imai K, Manago N, Mitsuda C, Naito Y, Nishimoto E, Sakazaki T, Fujiwara M, Froidevaux L, von Clarmann T, Stiller GP, Murtagh DP, Rong P, Mlynczak MG, Walker KA, Kinnison DE, Akiyoshi H, Nakamura T, Miyasaka T, Nishibori T, Mizobuchi S, Kikuchi K, Ozeki H, Takahashi C, Hayashi H, Sano T, Suzuki M, Takayanagi M, Shiotani M.  Validation of ozone data from the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES). Journal of Geophysical Research: Atmospheres. 2013 June 16; 118(11): 5750-5769. DOI: 10.1002/jgrd.50434.

    Suzuki M, Mitsuda C, Takahashi C, Iwata T, Manago N, Sano T, Kikuchi K, Ochiai S, Imai K, Nishimoto E, Naito Y, Hayashi H, Shiotani M.  Early Results From 4K-Cooled Superconducting Submm Wave Limb Emission Sounder SMILES Onboard ISS/JEM. International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. 2010; 38: 104-109. [Also: SANO, Takuki, and Masato SHIOTANI, ‘Early Results from 4K-Cooled Superconducting Sub-millimeter Wave Limb-Emission Sounder onboard ISS/JEM’, JASMA: Journal of the Japan Society of Microgravity Application, 28 (2011), 47–51  ]

    Jiang JH, Su H, Zhai C, Shen TJ, Wu T, Zhang J, Cole JN, von Salzen K, Donner LJ, Seman C, Del Genio A, Nazarenko LS, Dufresne J, Watanabe M, Morcrette C, Koshiro T, Kawai H, Gettelman A, Millan L, Read WG, Livesey NJ, Kasai Y, Shiotani M.  Evaluating the Diurnal Cycle of Upper-Tropospheric Ice Clouds in Climate Models Using SMILES Observations. Journal of the Atmospheric Sciences. 2015 March; 72(3): 1022-1044. DOI: 10.1175/JAS-D-14-0124.1.

    Sugita T, Kasai Y, Terao Y, Hayashida S, Manney GL, Daffer WH, Sagawa H, Suzuki M, Shiotani M, Walker KA, Boone CD, Bernath PF.  HCl and ClO profiles inside the Antarctic vortex as observed by SMILES in November 2009: comparisons with MLS and ACE-FTS instruments. Atmospheric Chemistry and Physics. 2013 November 18; 6(11): 3099-3113. DOI: 10.5194/amt-6-3099-2013.

    Millan L, Read WG, Kasai Y, Lambert A, Livesey NJ, Mendrok J, Sagawa H, Sano T, Shiotani M, Wu DL.  SMILES ice cloud products. Journal of Geophysical Research: Atmospheres. 2013 June 27; 118(12): 6468-6477. DOI: 10.1002/jgrd.50322.

    Ozeki H, Tamaki K, Mizobuchi S, Mitsuda C, Sano T, Suzuki M, Kikuchi K, Shiotani M.  Response characteristics of radio spectrometers of the Superconducting Submillimeter-Wave Limb-Emission Sounder (JEM/SMILES). 2011 IEEE International Geoscience and Remote Sensing Symposium, Vancouver, BC; 2011 July 24-29 2262-2265.

    Kikuchi K, Nishibori T, Ochiai S, Ozeki H, Irimajiri Y, Kasai Y, Koike M, Manabe T, Mizukoshi K, Murayama Y, Nagahama T, Sano T, Sato R, Seta M, Takahashi C, Takayanagi M, Masuko H, Inatani J, Suzuki M, Shiotani M.  Overview and early results of the Superconducting Submilimeter-Wave Limb-Emission Sounder (SMILES). Journal of Geophysical Research. 2010 December 7; 115(D23306): 12 pp. DOI: 10.1029/2010JD014379.

    Eriksson P, Rydberg B, Sagawa H, Johnston MS, Kasai Y.  Overview and sample applications of SMILES and Odin-SMR retrievals of upper tropospheric humidity and cloud ice mass. Atmospheric Chemistry and Physics. 2014 December 1; 14(23): 12613-12629. DOI: 10.5194/acp-14-12613-2014.

    Sakazaki T, Fujiwara M, Mitsuda C, Imai K, Manago N, Naito Y, Nakamura T, Akiyoshi H, Kinnison DE, Sano T, Suzuki M, Shiotani M.  Diurnal ozone variations in the stratosphere revealed in observations from the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on board the International Space Station (ISS). Journal of Geophysical Research: Atmospheres. 2013 April 16; 118(7): 2991-3006. DOI: 10.1002/jgrd.50220.

    Mizobuchi S, Kikuchi K, Ochiai S, Nishibori T, Sano T, Tamaki K, Ozeki H.  In-orbit measurement of the AOS (Acousto-Optical Spectrometer) response using frequency comb signals. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. 2012 June; 5(3): 977-983. DOI: 10.1109/JSTARS.2012.2196413.

    Imai K, Fujiwara M, Inai Y, Manago N, Suzuki M, Sano T, Mitsuda C, Naito Y, Hasebe F, Koide T, Shiotani M.  Comparison of ozone profiles between Superconducting Submillimeter-Wave Limb-Emission Sounder and worldwide ozonesonde measurements. Journal of Geophysical Research: Atmospheres. 2013 November 27; 118(22): 12,755-12,765. DOI: 10.1002/2013JD021094.

    Ochiai S, Irimajiri Y, Kikuchi K, Nishibori T, Sano T, Sato R, Manabe T, Ozeki H, Shiotani M.  Performance verification and calibration of Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES). 2010 IEEE International Geoscience and Remote Sensing Symposium, Honolulu, HI; 2010 July 25-30 4275-4277.

    Suzuki M, Mitsuda C, Kikuchi K, Nishibori T, Ochiai S, Ozeki H, Sano T, Mizobuchi S, Takahashi C, Manago N, Imai K, Naito Y, Hayashi H, Nishimoto E, Shiotani M.  Overview of the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) and sensitivity to chlorine monoxide, ClO. IEEJ Transactions on Fundamentals and Materials. 2012; 132(8): 609-615. DOI: 10.1541/ieejfms.132.609.

    Suzuki M, Ochiai S, Mitsuda C, Imai K, Manabe T, Kikuchi K, Nishibori T, Manago N, Iwata Y, Sano T, Shiotani M.  Verification of pointing and antenna pattern knowledge of Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES). 2011 IEEE International Geoscience and Remote Sensing Symposium, Vancouver, BC; 2011 July 24-29 3688-3691.

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Ground Based Results Publications

    Takahashi C, Ochiai S, Suzuki M.  Operational retrieval algorithms for JEM/SMILES level 2 data processing system. Journal of Quantitative Spectroscopy and Radiative Transfer. 2010 January; 111(1): 160-173. DOI: 10.1016/j.jqsrt.2009.06.005.

    Takahashi C, Suzuki M, Mitsuda C, Ochiai S, Manago N, Hayashi H, Iwata Y, Imai K, Sano T, Takayanagi M, Shiotani M.  Capability for ozone high-precision retrieval on JEM/SMILES observation. Advances in Space Research. 2011; 48(6): 1076-1085. DOI: 10.1016/j.asr.2011.04.038.

    Baron P, Urban J, Sagawa H, Moller J, Murtagh DP, Mendrok J, Dupuy E, Sato TO, Ochiai S, Suzuki K, Manabe T, Nishibori T, Kikuchi K, Sato R, Takayanagi M, Murayama Y, Shiotani M, Kasai Y.  The Level 2 research product algorithms for the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES). Atmospheric Measurement Techniques Discussions. 2011 June 9; 4(3): 3593-3645. DOI: 10.5194/amtd-4-3593-2011.

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ISS Patents

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Related Publications

    Parrish A, Boyd IS, Nedoluha GE, Bhartia PK, Frith SM, Kramarova NA, Connor BJ, Bodeker GE, Froidevaux L, Shiotani M, Sakazaki T.  Diurnal variations of stratospheric ozone measured by ground-based microwave remote sensing at the Mauna Loa NDACC site: measurement validation and GEOSCCM model comparison. Atmospheric Chemistry and Physics. 2014 July 16; 14(14): 7255-7272. DOI: 10.5194/acp-14-7255-2014.

    Tsunematsu S, Narasaki K, Okabayashi A, Otsuka K, Nishibori T, Kikuchi K.  Cryogenic System for Superconducting Submillimeter-wave Limb-Emission Sounder. TEION KOGAKU (Journal of Cryogenics and Superconductivity Society of Japan). 2014; 49(6): 301-306. DOI: 10.2221/jcsj.49.301. [Japanese]

    Hassler B, Petropavlovskikh I, Staehelin J, August T, Bhartia PK, Clerbaux C, Degenstein D, De Maziere M, Dinelli BM, Dudhia A, DuFour G, Frith SM, Froidevaux L, Godin-Beekmann S, Granville J, Harris NR, Hoppel K, Hubert D, Kasai Y, Kurylo MJ, Kyrola E, Lambert J, Levelt PF, McElroy CT, McPeters RD, Munro R, Nakajima H, Parrish A, Raspollini P, Remsberg EE, Rosenlof KH, Rozanov A, Sano T, Sasano Y, Shiotani M, Smit HG, Stiller GP, Tamminen J, Tarasick DW, Urban J, van der A RJ, Veefkind JP, Vigouroux C, von Clarmann T, von Savigny C, Walker KA, Weber M, Wild J, Zawodny JM.  Past changes in the vertical distribution of ozone - Part 1: Measurement techniques, uncertainties and availability. Atmospheric Measurement Techniques. 2014 May 21; 7(5): 1395-1427. DOI: 10.5194/amt-7-1395-2014.

    Smith AK, Harvey VL, Mlynczak MG, Funke B, Garcia-Comas M, Hervig M, Kaufmann M, Kyrola E, Lopez-Puertas M, McDade I, Randall CE, Russell III JM, Sheese PE, Shiotani M, Skinner WR, Suzuki M, Walker KA.  Satellite observations of ozone in the upper mesosphere. Journal of Geophysical Research: Atmospheres. 2013 June 16; 118(11): 5803-5821. DOI: 10.1002/jgrd.50445.

    Masuko H, Manabe T, Seta M, Kasai Y, Ochiai S, Irimajiri Y, Inatani J, Ikeda N, Nishibori T, Ozeki H, Sato R, Fujii Y, Nakajima T, Watanabe H, Kikuchi K, Koyama M.  Superconducting Submillimeter-wave Limb Emission Sounder (SMILES) onboard Japanese Experimental Module (JEM) of International Space Station (ISS). 2000 IEEE International Geoscience and Remote Sensing Symposium, Honolulu, HI; 2000 71-73.

    Stachnik RA, Millan L, Jarnot R, Monroe R, McLinden C, Kuhl S, Pukite J, Shiotani M, Suzuki M, Kasai Y, Goutail F, Pommereau JP, Dorf M, Pfeilsticker K.  Stratospheric BrO abundance measured by a balloon-borne submillimeterwave radiometer. Atmospheric Chemistry and Physics. 2013 March 22; 13(6): 3307-3319. DOI: 10.5194/acp-13-3307-2013.

    Sakazaki T, Shiotani M, Suzuki M, Kinnison DE, Zawodny JM, McHugh M, Walker KA.  Sunset–sunrise difference in solar occultation ozone measurements (SAGE II, HALOE, and ACE–FTS) and its relationship to tidal vertical winds. Atmospheric Chemistry and Physics. 2015 January 23; 15(4): 829-843. DOI: 10.5194/acp-15-829-2015. [Also: Sakazaki, T., M. Shiotani, M. Suzuki, D. Kinnison, J. M. Zawodny, M. McHugh, and others, ‘Sunset–sunrise Difference in Solar Occultation Ozone Measurements (SAGE II, HALOE, and ACE–FTS) and Its Relationship to Tidal Vertical Winds’, Atmospheric Chemistry and Physics Discussions, 14 (2014), 16043–83]

    Pawson S, Steinbrecht W, Charlton-Perez AJ, Fujiwara M, Karpechko AY, Petropavlovskikh I, Urban J, Weber M.  Update on Global Ozone: Past, Present, and Future. Scientific Assessment of Ozone Depletion: 2014; 2014.

    Kreyling D, Sagawa H, Wohltmann I, Lehmann R, Kasai Y.  SMILES zonal and diurnal variation climatology of stratospheric and mesospheric trace gasses: O3, HCl, HNO3, ClO, BrO, HOCl, HO2, and temperature. Journal of Geophysical Research: Atmospheres. 2013 October; 118: 16 pp. DOI: 10.1002/2012JD019420.

    Shiotani M, Kikuchi K, Sano T.  Mission Overview of the Superconducting Submillimeter-wave Limb-Emission Sounder (SMILES). JASMA: Journal of the Japan Society of Microgravity Application. 2011; 28(1): 42-46. [Japanese]

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Related Websites

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image NASA Image:  ISS020E042298 - SMILES (foreground) mounted on the Japanese Experiment Module Exposed Facility (JEM-EF).
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image SMILES mechanical cryocooler maintains a low temperature with longer orbit time. (Image credit: JAXA)
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image Component diagram of SMILES. (Image credit: JAXA)
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On January 23, 2010, SMILES observed destruction of the ozone layer at an altitude of 22 kilometers. Utilizing its high sensitivity, SMILES not only observes ozone depletion (shown in figure 1) but also captures changes in chlorine compound levels over a single day (the increase shown in figure 2 and the decrease shown in figure 3).

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