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| Titel |
Distributions of δD observations from IASI/MetOp across the globe and intercomparison with other instruments/measurements |
| VerfasserIn |
Jean-Lionel Lacour, Lieven Clarisse, Daniel Hurtmans, Cathy Clerbaux, John Worden, Matthias Schneider, Camille Risi, Pierre-François Coheur |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250096723
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| Publikation (Nr.) |
 EGU/EGU2014-12236.pdf |
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| Zusammenfassung |
| The Infrared Atmospheric Sounding Interferometer (IASI) onboard MetOp, through its
observations of the water isotopologues, has great potential to support research on
hydrological processes responsible for the moistening/drying of the atmosphere. The
instrumental characteristics of the spectrometer (low radiometric noise and good spectral
resolution) combined with its high sampling (global coverage twice a day) make it
particularly suitable for providing numerous observations of the isotopologues ratio (δD) of
water vapour in the troposphere.
Retrieving isotopologues ratios at the required accuracy is, however, a challenging
task. To get meaningful results, the retrieval needs to be well constrained. This can
be achieved, with the optimal estimation method, by using an a priori probability
density function containing correlation information between HDO and H2O. In this
presentation, first, we will show that the measurements are mainly sensitive to δD in the
troposphere between 3 and 6 km. We will illustrate the capabilities of IASI to provide δD
observations at high spatio-temporal resolution with some distributions across the
globe and we will discuss their added values to constrain hydrological processes.
Second, we will document how IASI observations compare to other remote sounding
observations of δD in the troposphere. Comparisons of IASI observations with the TES
sounder and with three ground-based NDACC FTIR (Izaña, Kalsruhe and Kiruna, data
generated within the project MUSICA) will be presented. The differences between
the instruments as well as the methodology to compare them will be exposed. We
will show that the different instruments agree within their own uncertainties and
vertical sensitivities, asserting the use of IASI δD observations for scientific purposes. |
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