Improvement in calibration algorithm of the AOS (acousto-optical spectrometer) using in-orbit measurement data

Mizobuchi, S.; Ozeki, Hiroyuki; Kikuchi, K.; Ochiai, Satoshi; Baron, Philippe; Nishibori, Toshiyuki

doi:10.1109/igarss.2012.6350417

Cited by 3 publications

(3 citation statements)

References 8 publications

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“…We also expect better retrievals thanks to improvements of the calibrated radiances and spectrometer frequencies spectra (Ochiai et al, 2012c;Mizobuchi et al, 2012a), and of the inversion methodology (e.g. joint inversion of different lines and bands).…”

Section: P Baron Et Al: Smiles Winds 6061 5 Conclusionmentioning

confidence: 99%

Observation of horizontal winds in the middle-atmosphere between 30° S and 55° N during the northern winter 2009–2010

et al. 2013

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Abstract. Although the links between stratospheric dynamics, climate and weather have been demonstrated, direct observations of stratospheric winds are lacking, in particular at altitudes above 30 km. We report observations of winds between 8 and 0.01 hPa (~35–80 km) from October 2009 to April 2010 by the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the International Space Station. The altitude range covers the region between 35–60 km where previous space-borne wind instruments show a lack of sensitivity. Both zonal and meridional wind components were obtained, though not simultaneously, in the latitude range from 30° S to 55° N and with a single profile precision of 7–9 m s–1 between 8 and 0.6 hPa and better than 20 m s–1 at altitudes above. The vertical resolution is 5–7 km except in the upper part of the retrieval range (10 km at 0.01 hPa). In the region between 1–0.05 hPa, an absolute value of the mean difference < 2 m s–1 is found between SMILES profiles retrieved from different spectroscopic lines and instrumental settings. Good agreement (absolute value of the mean difference of ~2 m s–1) is also found with the European Centre for Medium-Range Weather Forecasts (ECMWF) analysis in most of the stratosphere except for the zonal winds over the equator (difference > 5 m s−1). In the mesosphere, SMILES and ECMWF zonal winds exhibit large differences (> 20 m s–1), especially in the tropics. We illustrate our results by showing daily and monthly zonal wind variations, namely the semi-annual oscillation in the tropics and reversals of the flow direction between 50–55° N during sudden stratospheric warmings. The daily comparison with ECMWF winds reveals that in the beginning of February, a significantly stronger zonal westward flow is measured in the tropics at 2 hPa compared to the flow computed in the analysis (difference of ~20 m s–1). The results show that the comparison between SMILES and ECMWF winds is not only relevant for the quality assessment of the new SMILES winds, but it also provides insights on the quality of the ECMWF winds themselves. Although the instrument was not specifically designed for measuring winds, the results demonstrate that space-borne sub-mm wave radiometers have the potential to provide good quality data for improving the stratospheric winds in atmospheric models.

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Section: P Baron Et Al: Smiles Winds 6061 5 Conclusionmentioning

confidence: 99%

Observation of horizontal winds in the middle-atmosphere between 30° S and 55° N during the northern winter 2009–2010

et al. 2013

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“…The main components of SMILES are a limb-viewing antenna with a vertical beam width of 0.09 • [4], superconducting mixers, and acousto-optical spectrometer [5]. The SMILES limb observation scans the atmospheric limb from the bottom of the atmosphere to above the mesopause in a The tangent height can be actually retrieved from the spectra, mainly using the line-width information of an ozone line at 625.37 GHz.…”

Section: Smiles Limb Observationmentioning

confidence: 99%

Tangent height accuracy of superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on International Space Station (ISS)

Ochiai

Nishibori

Kikuchi

et al. 2012

2012 IEEE International Geoscience and Remote Sensing Symposium

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The attitude detection system installed in the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) had insufficient angular precision for limb observation. While the SMILES observation provides extremely low-noise emission spectra, the large error in the tangent height of limb viewing due to the poor knowledge of the attitude often limits the accuracy of the SMILES products, such as volume mixing ratio of atmospheric molecules. The attitude data from a ring laser gyroscope (RLG) installed in a nearby experiment unit, Monitor of All-sky X-ray Image (MAXI), is used to improve the tangent-height error. We create a customized attitude data set from the RLG data initialized with information from the SMILES star sensor. Applying this customized RLG attitude, we can know the tangent height of limb observations with an improved precision of less than 140 m.

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“…In coming work, SMILES mesospheric winds will be validated using ground-based radar observations. We also expect better retrievals thanks to improvements of the calibrated radiances and spectrometer frequencies spectra (Ochiai et al, 2012c;Mizobuchi et al, 2012a), and of the inversion methodology (e.g. joint inversion of different lines and bands).…”

Section: P Baron Et Al: Smiles Winds 6061 5 Conclusionmentioning

confidence: 99%

Observation of horizontal winds in the middle-atmosphere between 30° S and 55° N during the northern winter 2009–2010

Baron¹,

Murtagh²,

Urban³

et al. 2012

Preprint

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Although the links between stratospheric dynamics, climate and weather have been demonstrated, direct observations of stratospheric winds are lacking. We report observations of winds between 8 and 0.01 hPa (~35–80 km) from October 2009 to April 2010 by the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the International Space Station. The altitude range covers the region between 35–60 km where previous space-borne wind instruments show a lack of sensitivity. Both zonal and meridional wind components were obtained, though not simultaneously, in the latitude range from 30° S to 55° N and with a single profile precision of 7–9 m s⁻¹ between 8 and 0.6 hPa and better than 20 m s⁻¹ at altitudes above. The vertical resolution is 5–7 km except in the upper part of the retrieval range (10 km at 0.01 hPa). In the region between 1–0.05 hPa, a mean difference <2 m s⁻¹ is found between SMILES profiles retrieved from different spectroscopic lines and instrumental settings. Good agreement (mean difference of ~2 m s⁻¹) is also found with the European Centre for Medium-Range Weather Forecasts (ECMWF) analysis in most of the stratosphere except for the zonal winds over the equator (mean difference of 5–10 m s⁻¹). In the mesosphere, SMILES and ECMWF zonal winds exhibit large differences (> 20 m s⁻¹), especially in the tropics. We illustrate our results by showing daily and monthly zonal wind variations, namely the semi-annual oscillation in the tropics and reversals of the flow direction between 50° N–55° N during sudden stratospheric warmings in the stratosphere. The daily comparison with ECMWF winds reveals that in the beginning of February, a significantly stronger zonal westward flow is measured in the tropics at 2 hPa compared to the flow computed in the analysis (difference of ~20 m s⁻¹). The results show that the comparison between SMILES and ECMWF winds is not only relevant for the quality assessment of the new SMILES winds but it also provides insights on the quality of the ECMWF winds themselves. Although the instrument was not specifically designed for measuring winds, the results demonstrate that space-borne sub-mm wave radiometers have the potential to provide good quality data for improving the stratospheric winds in atmospheric models

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Improvement in calibration algorithm of the AOS (acousto-optical spectrometer) using in-orbit measurement data

Cited by 3 publications

References 8 publications

Observation of horizontal winds in the middle-atmosphere between 30° S and 55° N during the northern winter 2009–2010

Observation of horizontal winds in the middle-atmosphere between 30° S and 55° N during the northern winter 2009–2010

Tangent height accuracy of superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on International Space Station (ISS)

Observation of horizontal winds in the middle-atmosphere between 30° S and 55° N during the northern winter 2009–2010

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