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Titel |
Validation of MIPAS-ENVISAT H2O operational data collected between July 2002 and March 2004 |
VerfasserIn |
G. Wetzel, H. Oelhaf, G. Berthet, A. Bracher, C. Cornacchia, D. G. Feist, H. Fischer, A. Fix, M. Iarlori, A. Kleinert, A. Lengel, M. Milz, L. Mona, S. C. Müller, J. Ovarlez, G. Pappalardo, C. Piccolo, P. Raspollini, J.-B. Renard, V. Rizi, S. Rohs, C. Schiller, G. Stiller, M. Weber, G. Zhang |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7316
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 13, no. 11 ; Nr. 13, no. 11 (2013-06-14), S.5791-5811 |
Datensatznummer |
250018704
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Publikation (Nr.) |
copernicus.org/acp-13-5791-2013.pdf |
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Zusammenfassung |
Water vapour (H2O) is one of the operationally retrieved key species of
the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS)
instrument aboard the Environmental Satellite (ENVISAT) which was launched
into its sun-synchronous orbit on 1 March 2002 and operated until April
2012. Within the MIPAS validation activities, independent observations from
balloons, aircraft, satellites, and ground-based stations have been compared
to European Space Agency (ESA) version 4.61 operational H2O data
comprising the time period from July 2002 until March 2004 where MIPAS
measured with full spectral resolution. No significant bias in the MIPAS
H2O data is seen in the lower stratosphere (above the hygropause)
between about 15 and 30 km. Differences of H2O quantities observed by
MIPAS and the validation instruments are mostly well within the combined
total errors in this altitude region. In the upper stratosphere (above about
30 km), a tendency towards a small positive bias (up to about 10%) is
present in the MIPAS data when compared to its balloon-borne counterpart
MIPAS-B, to the satellite instruments HALOE (Halogen Occultation Experiment)
and ACE-FTS (Atmospheric Chemistry Experiment, Fourier Transform
Spectrometer), and to the millimeter-wave airborne sensor AMSOS (Airborne Microwave
Stratospheric Observing System). In the mesosphere the situation is unclear
due to the occurrence of different biases when comparing HALOE and ACE-FTS
data. Pronounced deviations between MIPAS and the correlative instruments
occur in the lowermost stratosphere and upper troposphere, a region where
retrievals of H2O are most challenging. Altogether it can be concluded
that MIPAS H2O profiles yield valuable information on the vertical
distribution of H2O in the stratosphere with an overall accuracy of
about 10 to 30% and a precision of typically 5 to 15% – well within
the predicted error budget, showing that these global and continuous data
are very valuable for scientific studies. However, in the region around the
tropopause retrieved MIPAS H2O profiles are less reliable, suffering
from a number of obstacles such as retrieval boundary and cloud effects,
sharp vertical discontinuities, and frequent horizontal gradients in both
temperature and H2O volume mixing ratio (VMR). Some profiles are
characterized by retrieval instabilities. |
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