Karlsruhe optimized and precise radiative transfer algorithm. Part I: requirements, justification, and model error estimation

Stiller, G. P.; Hoepfner, Michael; Kuntz, M.; Clarmann, T. von; Echle, Georg; Fischer, H.; Funke, B.; Glatthor, N.; Hase, Frank; Kemnitzer, Holger; Zorn, Sabine

doi:10.1117/12.317754

Cited by 40 publications

(33 citation statements)

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“…This code is similar to SFIT2, but retrieves profiles on a logarithmic volume mixing ratio scale. The radiative transfer code used is KOPRA Kuntz et al, 1998;Stiller et al, 1998]. NCEP temperature profiles, smoothly merged with the CIRA86 climatology (http://badc.rl.ac.uk/data/cira) above 45 km, were used for the analysis.…”

Section: Discussionmentioning

confidence: 99%

Long‐term trends of inorganic chlorine from ground‐based infrared solar spectra: Past increases and evidence for stabilization

Rinsland

2003

J. Geophys. Res.

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[1] Long-term time series of hydrogen chloride (HCl) and chlorine nitrate (ClONO 2 ) total column abundances has been retrieved from high spectral resolution ground-based solar absorption spectra recorded with infrared Fourier transform spectrometers at nine NDSC (Network for the Detection of Stratospheric Change) sites in both Northern and Southern Hemispheres. The data sets span up to 24 years and most extend until the end of 2001. The time series of Cl y (defined here as the sum of the HCl and ClONO 2 columns) from the three locations with the longest time-span records show rapid increases until the early 1990s superimposed on marked day-to-day, seasonal and inter-annual variability. Subsequently, the buildup in Cl y slows and reaches a broad plateau after 1996, also characterized by variability. A similar time evolution is also found in the total chlorine concentration at 55 km altitude derived from Halogen Occultation Experiment (HALOE) global observations since 1991. The stabilization of inorganic chlorine observed in both the total columns and at 55 km altitude indicates that the near-global 1993 organic chlorine (CCl y ) peak at the Earth's surface has now propagated over a broad altitude range in the upper atmosphere, though the time lag is difficult to quantify precisely from the current data sets, due to variability. We compare the three longest measured time series with two-dimensional model calculations extending from 1977 to 2010, based on a halocarbon scenario that assumes past measured trends and a realistic extrapolation into the future. The model predicts broad Cl y maxima consistent with the long-term observations, followed by a slow Cl y decline reaching 12-14% relative to the peak by 2010. The data reported here confirm the effectiveness of the Montreal Protocol and its Amendments and Adjustments in progressively phasing out the major man-related perturbations of the stratospheric ozone layer, in particular, the anthropogenic chlorinebearing source gases. Citation: Rinsland, C. P., et al., Long-term trends of inorganic chlorine from ground-based infrared solar spectra: Past increases and evidence for stabilization,

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Section: Discussionmentioning

confidence: 99%

Long‐term trends of inorganic chlorine from ground‐based infrared solar spectra: Past increases and evidence for stabilization

Rinsland

2003

J. Geophys. Res.

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“…In the case of the Izaña Observatory the effective height is about the same as the one used by the operational algorithm, but the effective temperature ranges from −50 • C in winter months to −45 • C in summer months. With the parameterisation of Van Roozendael et al (1998) we expect a typical error of −0.4% during the summer months due to these simplifications. …”

Section: Principles Of the Brewer Retrievalmentioning

confidence: 99%

“…The FTIR retrieval (PROFFIT, Hase et al, 2004) applies a precise radiative transfer model (KOPRA, Höpfner et al, 1998;Kuntz et al, 1998;Stiller et al, 1998). KOPRA is a line-by-line model which simulates the measured spectra.…”

Section: Principles Of the Ftir Retrievalmentioning

confidence: 99%

Comparison of ground-based Brewer and FTIR total column O<sub>3</sub> monitoring techniques

et al. 2008

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Abstract.We compare the currently most precise, groundbased total O 3 measurement techniques: Brewer and FTIR. We give an overview of the similarities and the differences between the measurements and the retrieval approaches of both experiments. We compare coincident measurements performed at the Atmospheric Observatory of Izaña from 2005 to 2007 and demonstrate that, if the properties of the instruments are well characterised, the scatter between both experiments is as small as 0.5%. This is in agreement with the theoretical predictions and confirms empirically that both techniques are able to monitor total O 3 amounts with a precision of better than 0.4%. However, we found systematic differences between both techniques of around 4.5%, which we think are mainly due to discrepancies between the applied UV and infrared spectroscopic parameters.

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“…The data used for comparison are based on IMK spectra version V3O and are based on calibrated radiance spectra generated by offline level-1 re-processing (ESA version IPF 4.61/4.62). The scientific data processor (von Clarmann et al, 2003a,b;Funke et al, 2001) has been developed and is operated by the IMK, Karlsruhe, Germany, in cooperation with the IAA in Granada, Spain, and uses the Karlsruhe Optimized and Precise Radiative transfer Algorithm (KOPRA) as a forward model for the retrieval Stiller et al, 1998;Stiller, 2000). The MIPAS-IMK data have been chosen instead of the ESA data, because the ESA data do not cover all species considered in our intercomparison, particularly ClONO 2 is missing in the ESA data set, the IMK data often cover a wider altitude range, often are less oscillatory, and use a more rigorous cloud rejection threshold.…”

Section: Mipasmentioning

confidence: 99%

Intercomparison of ILAS-II version 1.4 and version 2 target parameters with MIPAS-Envisat measurements

et al. 2008

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Abstract. This paper assesses the mean differences between the two ILAS-II data versions (1.4 and 2) by comparing them with MIPAS measurements made between May and October 2003. For comparison with ILAS-II results, MIPAS data processed at the Institut für Meteorologie und Klimaforschung, Karlsruhe, Germany (IMK) in cooperation with the Instituto de Astrofísica de Andalucía (IAA) in Granada, Spain, were used. The coincidence criteria of ±300 km in space and ±12 h in time for H 2 O, N 2 O, and CH 4 and the coincidence criteria of ±300 km in space and ±6 h in time for ClONO 2 , O 3 , and HNO 3 were used. The ILAS-II data were separated into sunrise (= Northern Hemisphere) and sunset (= Southern Hemisphere). For the sunrise data, a clear improvement from version 1.4 to version 2 was observed for H 2 O, CH 4 , ClONO 2 , and O 3 . In particular, the ILAS-II version 1.4 mixing ratios of H 2 O and CH 4 were unrealistically small, and those of ClONO 2 above altitudes of 30 km unrealistically large. For N 2 O and HNO 3 , there were no large differences between the two versions. Contrary to the Northern Hemisphere, where some exceptional profiles deviated significantly from known climatology, no such outlying profiles were found in the Southern Hemisphere for both versions. Generally, the ILAS-II version 2 data were in better agreement with the MIPAS data than the version 1.4, and are recommended for quantitative analysis in the stratosphere. For H 2

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Karlsruhe optimized and precise radiative transfer algorithm. Part I: requirements, justification, and model error estimation

Cited by 40 publications

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Long‐term trends of inorganic chlorine from ground‐based infrared solar spectra: Past increases and evidence for stabilization

Long‐term trends of inorganic chlorine from ground‐based infrared solar spectra: Past increases and evidence for stabilization

Comparison of ground-based Brewer and FTIR total column O<sub>3</sub> monitoring techniques

Intercomparison of ILAS-II version 1.4 and version 2 target parameters with MIPAS-Envisat measurements

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Karlsruhe optimized and precise radiative transfer algorithm. Part I: requirements, justification, and model error estimation

Cited by 40 publications

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Long‐term trends of inorganic chlorine from ground‐based infrared solar spectra: Past increases and evidence for stabilization

Long‐term trends of inorganic chlorine from ground‐based infrared solar spectra: Past increases and evidence for stabilization

Comparison of ground-based Brewer and FTIR total column O&lt;sub&gt;3&lt;/sub&gt; monitoring techniques

Intercomparison of ILAS-II version 1.4 and version 2 target parameters with MIPAS-Envisat measurements

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Comparison of ground-based Brewer and FTIR total column O<sub>3</sub> monitoring techniques