Improved Limb Atmospheric Spectrometer (ILAS) for stratospheric ozone layer measurements by solar occultation technique

Sasano, Yasuhiro; Yokota, Tatsuya; Kanzawa, Hiroshi

doi:10.1029/1998gl900276

Cited by 91 publications

(82 citation statements)

References 6 publications

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“…On the same platform, NO 2 was observed in the infrared by the Improved Stratospheric and Mesospheric Sounder (ISAMS) by means of pressure modulator radiometer technique (Reburn et al, 1996) and by the Cryogenic Limb Array Etalon Spectrometer (CLAES; Dessler et al, 1996). Further satellite sensors measuring NO 2 in the infrared spectral region are the two Improved Limb Atmospheric Spectrometers (ILAS I and II; Sasano et al, 1999;Nakajima et al, 2006) and the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS; Bernath et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

Validation of MIPAS-ENVISAT NO<sub>2</sub> operational data

et al. 2007

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The comparison to ACE satellite observations exhibits only a small negative bias of MIPAS which appears not to be significant. The independent satellite instruments HALOE, SAGE II, and POAM III confirm in common for the spring-summer time period a negative bias of MIPAS in the Arctic and a positive bias in the Antarctic middle and upper stratosphere exceeding frequently the combined systematic error limits. In contrast to the ESA operational processor, the IMK/IAA retrieval code allows accurate inference of NO 2 volume mixing ratios under consideration of all important non-LTE proCorrespondence to: G. Wetzel (gerald.wetzel@imk.fzk.de) cesses. Large differences between both retrieval results appear especially at higher altitudes, above about 50 to 55 km. These differences might be explained at least partly by non-LTE under polar winter conditions but not at mid-latitudes. Below this altitude region mean differences between both processors remain within 5% (during night) and up to 10% (during day) under undisturbed (September 2002) conditions and up to 40% under perturbed polar night conditions (February and March 2004). The intercomparison of ground-based NDACC observations shows no significant bias between the FTIR measurements in Kiruna (68 • N) and MIPAS in summer 2003 but larger deviations in autumn and winter. The mean deviation over the whole comparison period remains within 10%. A mean negative bias of 15% for MIPAS daytime and 8% for nighttime observations has been determined for UV-vis comparisons over Harestua (60 • N). Results of a pole-to-pole comparison of ground-based DOAS/UV-visible sunrise and MIPAS mid-morning column data has shown that the mean agreement in 2003 falls within the accuracy limit of the comparison method. Altogether, it can be indicated that MIPAS NO 2 profiles yield valuable information on the vertical distribution of NO 2 in the lower and middle stratosphere (below about 45 km) during day and night with an overall accuracy of about 10-20% and a precision of typically 5-15% such that the data are useful for scientific studies. In cases where extremely high NO 2 occurs in the mesosphere (polar winter) retrieval results in the lower and middle stratosphere are less accurate than under undisturbed atmospheric conditions.

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Section: Introductionmentioning

confidence: 99%

Validation of MIPAS-ENVISAT NO<sub>2</sub> operational data

et al. 2007

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“…The Improved Limb Atmospheric Spectrometer (ILAS) is a solar occultation satellite sensor which measures the absorption of stratospheric species in the infrared region of solar radiation [Sasano et al, 1999a]. It was launched on board the Advanced Earth Observing Satellite (ADEOS) in August 1996.…”

Section: Introductionmentioning

confidence: 99%

A comparison of Arctic HNO₃ profiles measured by the Improved Limb Atmospheric Spectrometer and balloon‐borne sensors

Koike¹,

Kondo²,

Irie³

et al. 2000

J. Geophys. Res.

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Balloon-Borne MeasurementsFrom Kiruna, four balloon-borne instruments measuring HNO3 or NOy were flown a total of six times as shown in Table 1. From Fairbanks, three instruments were flown, once each.Except for the Chemiluminescence Detector (CLD) in situ total reactive nitrogen (NOy) measurements, all of the measurements were performed by remote sensing using absorption or emission spectra of HNO3 in the infrared region. 6761

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“…Model denitrification was compared with Version 5.20 observations from the Improved Limb Atmospheric Spectrometer (ILAS) on-board the Advanced Earth Observing Satellite (ADEOS) (Sasano et al, 1999;Sasano, 2002). Vertical distributions of measured atmospheric components (including HNO 3 , O 3 , N 2 O and aerosol extinction coefficient) were obtained by constant solar tracking.…”

Section: Comparison With Ilasmentioning

confidence: 99%

3-D microphysical model studies of Arctic denitrification: comparison with observations

et al. 2005

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Abstract. Simulations of Arctic denitrification using a 3-D chemistry-microphysics transport model are compared with observations for the winters 1994/95, 1996/97 and 1999/2000. The model of Denitrification by Lagrangian Particle Sedimentation (DLAPSE) couples the full chemical scheme of the 3-D chemical transport model, SLIMCAT, with a nitric acid trihydrate (NAT) growth and sedimentation scheme. We use observations from the Microwave Limb Sounder (MLS) and Improved Limb Atmospheric Sounder (ILAS) satellite instruments, the balloon-borne Michelsen Interferometer for Passive Atmospheric Sounding (MIPAS-B), and the in situ NO y instrument on-board the ER-2. As well as directly comparing model results with observations, we also assess the extent to which these observations are able to validate the modelling approach taken. For instance, in 1999/2000 the model captures the temporal development of denitrification observed by the ER-2 from late January into March. However, in this winter the vortex was already highly denitrified by late January so the observations do not provide a strong constraint on the modelled rate of denitrification. The model also reproduces the MLS observations of denitrification in early February 2000. In 1996/97 the model captures the timing and magnitude of denitrification as observed by ILAS, although the lack of observations north of ∼67 • N in the beginning of February make it difficult to constrain the actual timing of onset. The comparison for this winter does not support previous conclusions that denitrification must be caused by an ice-mediated process. In 1994/95 the model notably underestimates the magnitude of denitrification observed during a single balloon flight of the MIPAS-B instruCorrespondence to: S. Davies (stewart@env.leeds.ac.uk) ment. Agreement between model and MLS HNO 3 at 68 hPa in mid-February 1995 is significantly better. Sensitivity tests show that a 1.5 K overall decrease in vortex temperatures, or a factor 4 increase in assumed NAT nucleation rates, produce the best statistical fit to MLS observations. Both adjustments would be required to bring the model into agreement with the MIPAS-B observations. The agreement between the model and observations suggests that a NAT-only denitrification scheme (without ice), which was discounted by previous studies, must now be considered as one mechanism for the observed Arctic denitrification. The timing of onset and the rate of denitrification remain poorly constrained by the available observations.

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Improved Limb Atmospheric Spectrometer (ILAS) for stratospheric ozone layer measurements by solar occultation technique

Abstract: The corresponding data is now publicly available for further analyses by the atmospheric community.

Cited by 91 publications

References 6 publications

Validation of MIPAS-ENVISAT NO<sub>2</sub> operational data

Validation of MIPAS-ENVISAT NO<sub>2</sub> operational data

A comparison of Arctic HNO₃ profiles measured by the Improved Limb Atmospheric Spectrometer and balloon‐borne sensors

3-D microphysical model studies of Arctic denitrification: comparison with observations

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Improved Limb Atmospheric Spectrometer (ILAS) for stratospheric ozone layer measurements by solar occultation technique

Abstract: The corresponding data is now publicly available for further analyses by the atmospheric community.

Cited by 91 publications

References 6 publications

Validation of MIPAS-ENVISAT NO&lt;sub&gt;2&lt;/sub&gt; operational data

Validation of MIPAS-ENVISAT NO&lt;sub&gt;2&lt;/sub&gt; operational data

A comparison of Arctic HNO3 profiles measured by the Improved Limb Atmospheric Spectrometer and balloon‐borne sensors

3-D microphysical model studies of Arctic denitrification: comparison with observations

Contact Info

Product

Resources

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Validation of MIPAS-ENVISAT NO<sub>2</sub> operational data

Validation of MIPAS-ENVISAT NO<sub>2</sub> operational data

A comparison of Arctic HNO₃ profiles measured by the Improved Limb Atmospheric Spectrometer and balloon‐borne sensors