MIPAS reduced spectral resolution UTLS-1 mode measurements of temperature,  O&amp;lt;sub&amp;gt;3&amp;lt;/sub&amp;gt;, HNO&amp;lt;sub&amp;gt;3&amp;lt;/sub&amp;gt;, N&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;O, H&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;O and relative humidity over ice: retrievals and comparison to MLS

Chauhan, Swarup; Höpfner, Michael; Stiller, G. P.; Clarmann, T. von; Funke, B.; Glatthor, N.; Grabowski, U.; Linden, A.; Kellmann, S.; Milz, M.; Steck, T.; Fischer, H.; Froidevaux, L.; Lambert, A.; Santee, M. L.; Schwartz, M.; Read, W. G.; Livesey, N. J.

doi:10.5194/amt-2-337-2009

Cited by 24 publications

(25 citation statements)

References 41 publications

(47 reference statements)

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“…Above 50 km, this difference even exceeds 2 %. This is generally consistent with findings by Chauhan et al (2009), using other types of satellite measurements.…”

Section: Summary Conclusion and Outlooksupporting

confidence: 82%

“…Similar ECMWF biases at high altitudes have been found with satellite measurements from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument on the European environmental satellite ENVISAT and from the Microwave Limb Sounder (MLS) instrument on the U.S. Aura satellite (Chauhan et al, 2009). Further comparisons of ECMWF analyses and temperature data from MIPAS and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER, an instrument on the U.S.…”

Section: Comparison To Ecmwfmentioning

confidence: 61%

“…First RO profiles of the Earth's atmosphere were provided by the GPS/MET experiment in intermittent periods from 1995 and 1997 (Rocken et al, 1997) Atmospheric profiles from RO are used for data assimilation in numerical weather prediction (NWP) (e.g., Healy and Thépaut, 2006;Cucurull and Derber, 2008) and in atmospheric and climate research (see Anthes, 2011;Steiner et al, 2011, for reviews). Most studies utilize RO profiles in the upper troposphere and lower stratosphere (UTLS) region, i.e., the altitude range from approximately 5 to 35 km, where RO profiles of pressure, geopotential height, and temperature are known to be of best quality (Scherllin-Pirscher et al, 2011b).…”

Section: Introductionmentioning

confidence: 99%

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Generation of a bending angle radio occultation climatology (BAROCLIM) and its use in radio occultation retrievals

et al. 2015

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Abstract. In this paper, we introduce a bending angle radio occultation climatology (BAROCLIM) based on Formosat-3/COSMIC (F3C) data. This climatology represents the monthly-mean atmospheric state from 2006 to 2012. Bending angles from radio occultation (RO) measurements are obtained from the accumulation of the change in the raypath direction of Global Positioning System (GPS) signals. Best quality of these near-vertical profiles is found from the middle troposphere up to the mesosphere. Beside RO bending angles we also use data from the Mass Spectrometer and Incoherent Scatter Radar (MSIS) model (modified for RO purposes) to expand BAROCLIM in a spectral model, which (theoretically) reaches from the surface up to infinity. Due to the very high quality of BAROCLIM up to the mesosphere, it can be used to detect deficiencies in current state-of-the-art analysis and reanalysis products from numerical weather prediction (NWP) centers. For bending angles derived from European Centre for Medium-Range Weather Forecasts (ECMWF) analysis fields from 2006 to 2012, e.g., we find a positive bias of 0.5 to 1 % at 40 km, which increases to more than 2 % at 50 km. BAROCLIM can also be used as a priori information in RO profile retrievals. In contrast to other a priori information (i.e., MSIS) we find that the use of BAROCLIM better preserves the mean of raw RO measurements. Global statistics of statistically optimized bending angle and refractivity profiles also confirm that BARO-CLIM outperforms MSIS. These results clearly demonstrate the utility of BAROCLIM.

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“…Above 50 km, this difference even exceeds 2 %. This is generally consistent with findings by Chauhan et al (2009), using other types of satellite measurements.…”

Section: Summary Conclusion and Outlooksupporting

confidence: 82%

Section: Comparison To Ecmwfmentioning

confidence: 61%

Section: Introductionmentioning

confidence: 99%

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Generation of a bending angle radio occultation climatology (BAROCLIM) and its use in radio occultation retrievals

et al. 2015

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“…Since 2005 MIPAS is operational again, however at reduced spectral but improved spatial resolution. While for many trace species the change of operation mode turned out to be advantageous in terms of precision, altitude-, and along-track horizontal resolution (Chauhan et al, 2009;von Clarmann et al, 2009b), HOCl could not yet successfully be retrieved from these reduced resolution measurements, because its lines could not be well enough resolved among the much stronger lines of interfering species. Thus MIPAS HOCl retrievals are available only from June 2002to March 2004 HOCl is retrieved from MIPAS spectra using the IMK/IAA scientific MIPAS processor by constrained least-squares fitting of simulated to measured spectral radiances.…”

Section: Mipas Hocl Datamentioning

confidence: 99%

The MIPAS HOCl climatology

et al. 2012

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Abstract. Monthly zonal mean HOCl measurements by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) are presented for the period from June 2002to March 2004. Highest molar mixing ratios are found at pressure levels between 6 and 2 hPa, whereby largest mixing ratios occasionally exceed 200 ppt. The mixing ratio maximum is generally higher at lower altitudes in the summer hemisphere than in the winter hemisphere except for chlorine activation conditions in polar vortices, where enhanced HOCl abundances are also found in the lower stratosphere below about 10 hPa. During nighttime the maximum is found at higher altitudes than during daytime. Particularly low values (below 80 ppt) during daytime are found in subpolar regions in the winter hemisphere where HOCl photolysis is still strong but where HOCl precursors are less abundant than at other latitudes. The Antarctic polar winter HOCl distribution in 2002, the year of the split of the southern polar vortex, resembles northern polar winters rather than other southern polar winters. Increased HOCl amounts in response to the so-called Halloween solar proton event in autumn 2003 affect the representativeness of data recorded during this particular episode. Calculations with the EMAC model reproduce the measured HOCl distribution reasonably well. MIPAS measurements confirm that the reaction rate constants for HO 2 + ClO −→ HOCl + O 2 from the most recent JPL recommendation allow much more realistic modelling of HOCl than reaction rate constants from earlier recommendations. Modeled HOCl mixing ratios, however, are still too low except in the polar winter stratosphere where the model overestimates the HOCl abundance.

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“…The comparison of the two O 3 profile datasets were performed by finding pairs of the coincident measurements, using a methodology which is based on the works by Dupuy et al (2009), von Clarmann (2006, and Chauhan et al (2009). We set a horizontal distance of within 300 km on the measurement location as a criteria for selecting a pair of coincident measurements between SMILES and other satellite/balloon-borne instruments.…”

Section: Methodology Of Comparisonsmentioning

confidence: 99%

Validation of stratospheric and mesospheric ozone observed by SMILES from International Space Station

et al. 2013

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We observed ozone (O₃) in the vertical region between 250 and 0.0005 hPa (~ 12–96 km) using the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the Japanese Experiment Module (JEM) of the International Space Station (ISS) between 12 October 2009 and 21 April 2010. The new 4 K superconducting heterodyne receiver technology of SMILES allowed us to obtain a one order of magnitude better signal-to-noise ratio for the O₃ line observation compared to past spaceborne microwave instruments. The non-sun-synchronous orbit of the ISS allowed us to observe O₃ at various local times. We assessed the quality of the vertical profiles of O₃ in the 100–0.001 hPa (~ 16–90 km) region for the SMILES NICT Level 2 product version 2.1.5. The evaluation is based on four components: error analysis; internal comparisons of observations targeting three different instrumental setups for the same O₃ 625.371 GHz transition; internal comparisons of two different retrieval algorithms; and external comparisons for various local times with ozonesonde, satellite and balloon observations (ENVISAT/MIPAS, SCISAT/ACE-FTS, Odin/OSIRIS, Odin/SMR, Aura/MLS, TELIS). SMILES O₃ data have an estimated absolute accuracy of better than 0.3 ppmv (3%) with a vertical resolution of 3–4 km over the 60 to 8 hPa range. The random error for a single measurement is better than the estimated systematic error, being less than 1, 2, and 7%, in the 40–1, 80–0.1, and 100–0.004 hPa pressure regions, respectively. SMILES O₃ abundance was 10–20% lower than all other satellite measurements at 8–0.1 hPa due to an error arising from uncertainties of the tangent point information and the gain calibration for the intensity of the spectrum. SMILES O₃ from observation frequency Band-B had better accuracy than that from Band-A. A two month period is required to accumulate measurements covering 24 h in local time of O₃ profile. However such a dataset can also contain variation due to dynamical, seasonal, and latitudinal effects

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MIPAS reduced spectral resolution UTLS-1 mode measurements of temperature, O<sub>3</sub>, HNO<sub>3</sub>, N<sub>2</sub>O, H<sub>2</sub>O and relative humidity over ice: retrievals and comparison to MLS

Cited by 24 publications

References 41 publications

Generation of a bending angle radio occultation climatology (BAROCLIM) and its use in radio occultation retrievals

Generation of a bending angle radio occultation climatology (BAROCLIM) and its use in radio occultation retrievals

The MIPAS HOCl climatology

Validation of stratospheric and mesospheric ozone observed by SMILES from International Space Station

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