Simultaneous retrieval of T(p) and CO2 VMR from two-channel non-LTE limb radiances and application to daytime SABER/TIMED measurements

Rezac, Ladislav; Kutepov, A. A.; Russell, James M.; Feofilov, Artem; Yue, Jia; Goldberg, R. A.

doi:10.1016/j.jastp.2015.05.004

Cited by 60 publications

(82 citation statements)

References 62 publications

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“…A maximum of 15 sunrise profiles and 15 sunset profiles are obtained each day, with coverage weighted toward high latitudes. Although local time and latitude coverage are limited, measurements are not affected by nonlocal thermodynamic equilibrium processes, as is the case for infrared radiation emissions [ Rezac et al ., ]. Only fundamental bands were used for the retrievals of CO 2 and CO. ACE‐FTS retrievals are registered on a fixed altitude grid but the data set also includes pressures for each profile derived from the retrieved temperatures.…”

Section: Co2 and Co Measured By Ace‐fts And Co2 Measured By Sabermentioning

confidence: 99%

“…The SABER channels include CO 2 emission bands at 4.3 µm and 15 µm. A two‐channel algorithm (4.3 µm and 15 µm narrow band) was used to simultaneously retrieve profiles of kinetic temperature T k and CO 2 vmr from daytime radiance measurements, in the altitude range of 65–110 km [ Rezac et al ., ]. Similar to ACE‐FTS, SABER data are also delivered on a fixed altitude grid but include pressures derived from retrieved temperatures.…”

Section: Co2 and Co Measured By Ace‐fts And Co2 Measured By Sabermentioning

confidence: 99%

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Carbon dioxide trends in the mesosphere and lower thermosphere

et al. 2017

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We investigated trends of carbon dioxide (CO2) in the upper atmosphere, using data from the Atmosphere Chemistry Experiment Fourier Transform Spectrometer and from the Sounding of the Atmosphere using Broadband Emission Radiometry. Recent analyses of these measurements had indicated that CO2 above approximately 90 km appeared to be increasing about twice as fast as it was in the lower atmosphere. Models could not reproduce this differential CO2 trend, calculating instead that the proportional CO2 increase is approximately constant with altitude. We found three issues with the methodologies used to derive trends from CO2 profiles: the way that seasonal changes and sampling are accounted for in the analysis, referred to as deseasonalizing; the registration of profiles in pressure versus altitude coordinates; and data quality indicators. Each of these can have significant effects on the derivation of trends. We applied several deseasonalizing procedures, using both pressure and altitude coordinates, also used a time series fit without deseasonalizing, and applied data quality filters. The derived trends were approximately constant with pressure or altitude, about 5.5% per decade, consistent with lower atmosphere CO2 trends, and consistent with model calculations. We conclude that the difference between the trend of CO2 above the CO2 homopause and the trend in the lower, well‐mixed atmosphere is not statistically significant.

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Section: Co2 and Co Measured By Ace‐fts And Co2 Measured By Sabermentioning

confidence: 99%

Section: Co2 and Co Measured By Ace‐fts And Co2 Measured By Sabermentioning

confidence: 99%

Carbon dioxide trends in the mesosphere and lower thermosphere

et al. 2017

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“…Photochemical parameters are only important above 100 km for CO [Garcia et al, 2014]. The CO 2 concentration at 70 km is chosen because the SABER/TIMED profiles have the best reliability between 70 and 120 km [Rezac et al, 2015b]. The 1-D modelˈs lower boundary CO 2 concentration at the surface is also adjusted so that both the modelˈs output CO 2 profile and the SABER/TIMED CO 2 profile have the same CO 2 concentration at 70 km.…”

Section: Saber/timed Co 2 Data and 1-d Transport Modelmentioning

confidence: 99%

Impacts of SABER CO₂‐based eddy diffusion coefficients in the lower thermosphere on the ionosphere/thermosphere

et al. 2016

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This work estimates global‐mean Kzz using Sounding of the Atmosphere using Broadband Emission Radiometry/Thermosphere‐Ionosphere‐Mesosphere Energetics and Dynamics monthly global‐mean CO2 profiles and a one‐dimensional transport model. It is then specified as a lower boundary into the Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model (TIE‐GCM). Results first show that global‐mean CO2 in the mesosphere and lower thermosphere region has annual and semiannual oscillations (AO and SAO) with maxima during solstice seasons along with a primary maximum in boreal summer. Our calculated AO and SAO in global‐mean CO2 are then modeled by AO and SAO in global‐mean Kzz. It is then shown that our estimated global‐mean Kzz is lower in magnitude than the suggested global‐mean Kzz from Qian et al. (2009) that can model the observed AO and SAO in the ionosphere/thermosphere (IT) region. However, our estimated global‐mean Kzz is similar in magnitude with recent suggestions of global‐mean Kzz in models with explicit gravity wave parameterization. Our work therefore concludes that global‐mean Kzz from global‐mean CO2 profiles cannot model the observed AO and SAO in the IT region because our estimated global‐mean Kzz may only be representing eddy diffusion due to gravity wave breaking. The difference between our estimated global‐mean Kzz and the global‐mean Kzz from Qian et al. (2009) thus represents diffusion and mixing from other nongravity wave sources not directly accounted for in the TIE‐GCM lower boundary conditions. These other sources may well be the more dominant lower atmospheric forcing behind the AO and SAO in the IT region.

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“…ALI has became a standard technique for spectrum formation calculations and for the computation of the non-LTE model stellar atmospheres. The ALI-ARMS code has been successfully applied to the diagnostics of a number of space infrared Earth's and Martian observations, both spectrally resolved (Kaufmann et al, 2002(Kaufmann et al, , 2003Maguire et al, 2002;Gusev et al, 2006) and broadband signals (Kutepov et al, 2006;Feofilov et al, 2009Rezac et al, 2015), as well as to study the infrared radiative cooling/heating in planetary atmospheres (Hartogh et al, 2005;Kutepov et al, 2007;.…”

Section: The Ali-arms Codementioning

confidence: 99%

“…3 In this study we employed our radiance model in both nonoverlapping and overlapping mode. In the latter case the calculations treat spectral line overlapping of all bands (within a band and between lines of different bands) of all isotopes in the line-by-line (LBL) fashion (technical discussion is detailed in Rezac et al, 2015). The effect of accounting for line overlapping is clearly demonstrated in spectrum plotted in red color.…”

Section: Importance Of Line Overlapping Along the Limb Losmentioning

confidence: 99%

Evidence of a significant rotational non-LTE effect in the CO<sub>2</sub> 4.3 µm PFS-MEX limb spectra

Kutepov

Rezac

2017

Atmos. Meas. Tech.

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Abstract. Since January 2004, the planetary Fourier spectrometer (PFS) on board the Mars Express satellite has been recording near-infrared limb spectra of high quality up to the tangent altitudes ≈ 150 km, with potential information on density and thermal structure of the upper Martian atmosphere. We present first results of our modeling of the PFS short wavelength channel (SWC) daytime limb spectra for the altitude region above 90 km. We applied a ro-vibrational non-LTE model based on the stellar astrophysics technique of accelerated lambda iteration (ALI) to solve the multispecies and multi-level CO 2 problem in the Martian atmosphere. We show that the long-standing discrepancy between observed and calculated spectra in the cores and wings of 4.3 µm region is explained by the non-thermal rotational distribution of molecules in the upper vibrational states 10011 and 10012 of the CO 2 main isotope second hot (SH) bands above 90 km altitude. The redistribution of SH band intensities from band branch cores into their wings is caused (a) by intensive production of the CO 2 molecules in rotational states with j > 30 due to the absorption of solar radiation in optically thin wings of 2.7 µm bands and (b) by a short radiative lifetime of excited molecules, which is insufficient at altitudes above 90 km for collisions to maintain rotation of excited molecules thermalized. Implications for developing operational algorithms for massive processing of PFS and other instrument limb observations are discussed.

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Simultaneous retrieval of T(p) and CO2 VMR from two-channel non-LTE limb radiances and application to daytime SABER/TIMED measurements

Cited by 60 publications

References 62 publications

Carbon dioxide trends in the mesosphere and lower thermosphere

Carbon dioxide trends in the mesosphere and lower thermosphere

Impacts of SABER CO₂‐based eddy diffusion coefficients in the lower thermosphere on the ionosphere/thermosphere

Evidence of a significant rotational non-LTE effect in the CO<sub>2</sub> 4.3 µm PFS-MEX limb spectra

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Simultaneous retrieval of T(p) and CO2 VMR from two-channel non-LTE limb radiances and application to daytime SABER/TIMED measurements

Cited by 60 publications

References 62 publications

Carbon dioxide trends in the mesosphere and lower thermosphere

Carbon dioxide trends in the mesosphere and lower thermosphere

Impacts of SABER CO2‐based eddy diffusion coefficients in the lower thermosphere on the ionosphere/thermosphere

Evidence of a significant rotational non-LTE effect in the CO&lt;sub&gt;2&lt;/sub&gt; 4.3 µm PFS-MEX limb spectra

Contact Info

Product

Resources

About

Impacts of SABER CO₂‐based eddy diffusion coefficients in the lower thermosphere on the ionosphere/thermosphere

Evidence of a significant rotational non-LTE effect in the CO<sub>2</sub> 4.3 µm PFS-MEX limb spectra