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| Titel |
Validation of MIPAS IMK/IAA methane profiles |
| VerfasserIn |
A. Laeng, J. Plieninger, T. von Clarmann, U. Grabowski, G. Stiller, E. Eckert, N. Glatthor, F. Haenel, S. Kellmann, M. Kiefer, A. Linden, S. Lossow, L. Deaver, A. Engel, M. Hervig, I. Levin, M. McHugh, S. Noël, G. Toon, K. Walker |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1867-1381
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 8, no. 12 ; Nr. 8, no. 12 (2015-12-16), S.5251-5261 |
| Datensatznummer |
250116725
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| Publikation (Nr.) |
 copernicus.org/amt-8-5251-2015.pdf |
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| Zusammenfassung |
| The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS)
is an infrared (IR) limb emission spectrometer on the Envisat platform. It
measures trace gas distributions during day and night, pole-to-pole, over an altitude range from 6 to 70 km in nominal mode
and up to 170 km in special modes, depending on the measurement mode, producing more
than 1000 profiles day−1. We present the results of a validation study of methane, version
V5R_CH4_222, retrieved with the IMK/IAA (Institut für Meteorologie und Klimaforschung,
Karlsruhe/Instituto de Astrofisica de Andalucia, Grenada) MIPAS scientific level 2 processor.
The level 1 spectra are provided by the ESA (European Space Agency) and version 5 was used. The time period
covered is 2005–2012, which corresponds to the period when MIPAS measured trace gas distributions at a reduced spectral
resolution of 0.0625 cm−1. The comparison with satellite instruments includes
the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS),
the HALogen Occultation Experiment (HALOE), the Solar Occultation For Ice Experiment
(SOFIE) and the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY).
Furthermore, comparisons with MkIV balloon-borne
solar occultation measurements and with air sampling measurements performed
by the University of Frankfurt are presented. The validation activities include
bias determination, assessment of stability, precision validation, analysis of histograms and
comparison of corresponding climatologies.
Above 50 km altitude, MIPAS methane mixing ratios agree within 3 % with
ACE-FTS and SOFIE. Between 30 and 40 km an agreement within 3 %
with SCIAMACHY has been found. In the middle stratosphere, there is no clear
indication of a MIPAS bias since comparisons with various instruments
contradict each other. In the lower stratosphere (below 25 km) MIPAS
CH4 is biased high with respect to satellite instruments, and the most likely estimate of this bias is 14 %.
However, in the comparison with CH4 data obtained from cryogenic whole-air sampler (cryosampler)
measurements, there is no evidence of a high bias in MIPAS between 20 and 25 km altitude.
Precision validation is performed on collocated MIPAS–MIPAS pairs and suggests a slight underestimation
of its uncertainties by a factor of 1.2. No significant evidence of an instrumental drift has been found. |
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