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MIPAS IMK/IAA carbon tetrachloride (CCl4) retrieval and first comparison with other instruments

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journal contribution
posted on 03.11.2017, 15:04 by Ellen Eckert, Thomas Von Clarmann, Alexandra Laeng, Gabriele P. Stiller, Bernd Funke, Norbert Glatthor, Udo Grabowski, Sylvia Kellmann, Michael Kiefer, Andrea Linden, Arne Babenhauserheide, Gerald Wetzel, Christopher Boone, Andreas Engel, Jeremy J. Harrison, Patrick E. Sheese, Kaley A. Walker, Peter F. Bernath
MIPAS thermal limb emission measurements were used to derive vertically resolved profiles of carbon tetrachloride (CCl4). Level-1b data versions MIPAS/5.02 to MIPAS/5.06 were converted into volume mixing ratio profiles using the level-2 processor developed at Karlsruhe Institute of Technology (KIT) Institute of Meteorology and Climate Research (IMK) and Consejo Superior de Investigaciones Científicas (CSIC), Instituto de Astrofísica de Andalucía (IAA). Consideration of peroxyacetyl nitrate (PAN) as an interfering species, which is jointly retrieved, and CO2 line mixing is crucial for reliable retrievals. Parts of the CO2 Q-branch region that overlap with the CCl4 signature were omitted, since large residuals were still found even though line mixing was considered in the forward model. However, the omitted spectral region could be narrowed noticeably when line mixing was accounted for. A new CCl4 spectroscopic data set leads to slightly smaller CCl4 volume mixing ratios. In general, latitude–altitude cross sections show the expected CCl4 features with highest values of around 90 pptv at altitudes at and below the tropical tropopause and values decreasing with altitude and latitude due to stratospheric decomposition. Other patterns, such as subsidence in the polar vortex during winter and early spring, are also visible in the distributions. The decline in CCl4 abundance during the MIPAS Envisat measurement period (July 2002 to April 2012) is clearly reflected in the altitude–latitude cross section of trends estimated from the entire retrieved data set.

Funding

The retrievals of IMK/IAA were partly performed on the HP XC4000 of the Scientific Supercomputing Center (SSC) Karlsruhe under project grant MIPAS. IMK data analysis was supported by DLR under contract number 50EE0901. MIPAS level 1B data were provided by ESA. We acknowledge support by Deutsche Forschungsgemeinschaft and Open Access Publishing Fund of Karlsruhe Institute of Technology. This work was supported by the DFG project for the “Consideration of lifetimes of tracers for the determination of stratospheric age spectra and the Brewer–Dobson Circulation (COLIBRI)”. The Atmospheric Chemistry Experiment (ACE), also known as SCISAT, is a Canadian-led mission mainly supported by the Canadian Space Agency and the Natural Sciences and Engineering Research Council of Canada. Balloon flights and data analysis of MIPAS-B data used here were supported by the European Space Agency (ESA), the German Aerospace Center (DLR), CNRS (Centre National de la Recherche Scientifique) and CNES (Centre National d’Etudes Spatiales). The article processing charges for this open-access publication were covered by a Research Centre of the Helmholtz Association.

History

Citation

Atmospheric Measurement Techniques, 2017, 10 (7), pp. 2727-2743

Author affiliation

/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy

Version

VoR (Version of Record)

Published in

Atmospheric Measurement Techniques

Publisher

European Geosciences Union (EGU), Copernicus Publications

issn

1867-1381

eissn

1867-8548

Acceptance date

08/06/2017

Copyright date

2017

Available date

03/11/2017

Publisher version

https://www.atmos-meas-tech.net/10/2727/2017/

Notes

Data availability. MIPAS data can be accessed at the following website: https://www.imk-asf.kit.edu/english/308.php. The cryosampler data can be obtained by contacting Andreas Engel via email (an.engel@iau.unifrankfurt.de). Information on MIPASB can be found at the following website: http://www.imk-asf.kit.edu/english/ffb.php. For SCISAT/ACE-FTS, the most recent data version is available from the ACE team, University of Waterloo, Canada. Publicly available validated data sets can be found at http://www.ace.uwaterloo.ca/data.html.

Language

en

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