Gain Nonlinearity Calibration of Submillimeter Radiometer for JEM/SMILES

Ochiai, Satoshi; Kikuchi, K.; Nishibori, Toshiyuki; Manabe, Tetsuya

doi:10.1109/jstars.2012.2193559

Cited by 14 publications

(7 citation statements)

References 7 publications

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“…This version updated a nonlinear gain calibration of spectrum brightness temperature (Ochiai et al, 2012a). As emphasized by Kasai et al (2013), the nonlinearity issue was one of the biggest causes of error in the retrieval of the O 3 VMR in the V215 retrieval processing.…”

Section: Level-1b Spectrum and Tangent Height Correctionmentioning

confidence: 99%

Vertical profile of δ<sup>18</sup>OOO from the middle stratosphere to lower mesosphere from SMILES spectra

et al. 2014

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Abstract.Ozone is known to have large oxygen isotopic enrichments of about 10 % in the middle stratosphere; however, there have been no reports of ozone isotopic enrichments above the middle stratosphere. We derived an enrichment δ 18 OOO in the stratosphere and the lower mesosphere from observations of the Superconducting SubmillimeterWave Limb-Emission Sounder (SMILES) onboard the International Space Station (ISS) using a retrieval algorithm optimized for the isotopic ratio. The retrieval algorithm includes (i) an a priori covariance matrix constrained by oxygen isotopic ratios in ozone, (ii) an optimization of spectral windows for ozone isotopomers and isotopologues, and (iii) common tangent height information for all windows. The δ 18 OOO by averaging the SMILES measurements at the latitude range of 20 to 40 • N from February to March in 2010 with solar zenith angle < 80 • was 13 % (at 32 km) with the systematic error of about 5 %. SMILES and past measurements were in good agreement, with δ 18 OOO increasing with altitude between 30 and 40 km. The vertical profile of δ 18 OOO obtained in this study showed an increase and a decrease with altitude in the stratosphere and mesosphere, respectively. The δ 18 OOO peak, 18 %, is found at the stratopause. The δ 18 OOO has a positive correlation with temperature in the range of 220-255 K, indicating that temperature can be a dominant factor to control the vertical profile of δ 18 OOO in the stratosphere and mesosphere. This is the first report of the observation of δ 18 OOO over a wide altitude range extending from the stratosphere to the mesosphere (28-57 km).

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Section: Level-1b Spectrum and Tangent Height Correctionmentioning

confidence: 99%

Vertical profile of δ<sup>18</sup>OOO from the middle stratosphere to lower mesosphere from SMILES spectra

et al. 2014

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“…The input power p ν is proportional to a sum of T ANT and system noise temperature T sys ; T sys includes system noise, the brightness coming from direction 0 and the emissions from the lossy reflectors. Coefficients α and α represent receiver gain nonlinearity (Ochiai et al, 2012a). α was 1.884 × 10 −6 and was measured in the pre-launch test.…”

Section: T O Sato Et Al: Error Analysis and Diurnal Variation Of Smentioning

confidence: 99%

Strato-mesospheric ClO observations by SMILES: error analysis and diurnal variation

et al. 2012

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Abstract. Chlorine monoxide (ClO) is the key species for anthropogenic ozone losses in the middle atmosphere. We observed ClO diurnal variations using the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the International Space Station, which has a non-sunsynchronous orbit. This includes the first global observations of the ClO diurnal variation from the stratosphere up to the mesosphere. The observation of mesospheric ClO was possible due to 10-20 times better signal-to-noise (S/N) ratio of the spectra than those of past or ongoing microwave/submillimeter-wave limb-emission sounders. We performed a quantitative error analysis for the strato-and mesospheric ClO from the Level-2 research (L2r) product version 2.1.5 taking into account all possible contributions of errors, i.e. errors due to spectrum noise, smoothing, and uncertainties in radiative transfer model and instrument functions. The SMILES L2r v2.1.5 ClO data are useful over the range from 0.01 and 100 hPa with a total error estimate of 10-30 pptv (about 10 %) with averaging 100 profiles. The SMILES ClO vertical resolution is 3-5 km and 5-8 km for the stratosphere and mesosphere, respectively. The SMILES observations reproduced the diurnal variation of stratospheric ClO, with peak values at mid-

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“…The SMILES instrument on board the International Space Station is a unique instrument that uses 4‐K superconductive heterodyne receivers to obtain low‐noise spectra in the submillimeter‐wave region (Kikuchi et al, ; Ochiai et al, ). We use the SMILES observation spectra ranging from 649.12 to 650.32 GHz and detect the HO

_{2}

transition at 649.701 GHz.…”

Section: Ho 2 Spectral Enhancements Above Sprite‐producing Thunderstomentioning

confidence: 99%

HO Generation Above Sprite‐Producing Thunderstorms Derived from Low‐Noise SMILES Observation Spectra

Yamada

Sato

Adachi³

et al. 2020

Geophysical Research Letters

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No direct observational evidence of sprite‐produced active radicals has been presented owing to the difficulty of observing a small event area in the nighttime mesosphere, whereas sprite chemical models have indicated that sprite discharge locally affects the atmospheric composition. We present the first observational evidence of a HO 2 production above sprite‐producing thunderstorms from the coincidence of temporal‐spatial observations of HO 2 spectra, sprite events, and thunderstorms by two space instruments, a submillimeter‐wave limb spectrometer and ultraviolet/visible Imager and a ground‐based very low frequency radiation lightning detection network. A total of three areas was identified with enhanced HO 2 levels of approximately 10 25 molecules. A chemical sprite model indicates an increase in HO 2 in the considered altitude region; however, the predicted production due to a single sprite event is smaller than the observed enhancement. Our observational results suggest that sprites potentially contribute 1% of nighttime background HO 2 generation at altitudes of 75–80 km globally.

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Gain Nonlinearity Calibration of Submillimeter Radiometer for JEM/SMILES

Cited by 14 publications

References 7 publications

Vertical profile of δ<sup>18</sup>OOO from the middle stratosphere to lower mesosphere from SMILES spectra

Vertical profile of δ<sup>18</sup>OOO from the middle stratosphere to lower mesosphere from SMILES spectra

Strato-mesospheric ClO observations by SMILES: error analysis and diurnal variation

HO Generation Above Sprite‐Producing Thunderstorms Derived from Low‐Noise SMILES Observation Spectra

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Gain Nonlinearity Calibration of Submillimeter Radiometer for JEM/SMILES

Cited by 14 publications

References 7 publications

Vertical profile of δ&lt;sup&gt;18&lt;/sup&gt;OOO from the middle stratosphere to lower mesosphere from SMILES spectra

Vertical profile of δ&lt;sup&gt;18&lt;/sup&gt;OOO from the middle stratosphere to lower mesosphere from SMILES spectra

Strato-mesospheric ClO observations by SMILES: error analysis and diurnal variation

HO Generation Above Sprite‐Producing Thunderstorms Derived from Low‐Noise SMILES Observation Spectra

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Vertical profile of δ<sup>18</sup>OOO from the middle stratosphere to lower mesosphere from SMILES spectra

Vertical profile of δ<sup>18</sup>OOO from the middle stratosphere to lower mesosphere from SMILES spectra