 |
| Titel |
Cross-validation of IASI/MetOp derived tropospheric δD with TES and ground-based FTIR observations |
| VerfasserIn |
J.-L. Lacour, L. Clarisse, J. Worden, M. Schneider, S. Barthlott, F. Hase, C. Risi, C. Clerbaux, D. Hurtmans, P.-F. Coheur |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1867-1381
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 8, no. 3 ; Nr. 8, no. 3 (2015-03-20), S.1447-1466 |
| Datensatznummer |
250116226
|
| Publikation (Nr.) |
 copernicus.org/amt-8-1447-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
| The Infrared Atmospheric Sounding Interferometer (IASI) flying onboard
MetOpA and MetOpB is able to capture fine isotopic variations of the HDO to
H2O ratio (δD) in the troposphere. Such observations at the
high spatio-temporal resolution of the sounder are of great interest to
improve our understanding of the mechanisms controlling humidity in the
troposphere. In this study we aim to empirically assess the validity of our
error estimation previously evaluated theoretically. To achieve this, we
compare IASI δD retrieved profiles with other available profiles of
δD, from the TES infrared sounder onboard AURA and from three
ground-based FTIR stations produced within the MUSICA project: the NDACC
(Network for the Detection of Atmospheric Composition Change) sites Kiruna
and Izaña, and the TCCON site Karlsruhe, which in addition to near-infrared
TCCON spectra also records mid-infrared spectra. We describe the achievable
level of agreement between the different retrievals and show that these
theoretical errors are in good agreement with empirical differences. The
comparisons are made at different locations from tropical to Arctic
latitudes, above sea and above land. Generally IASI and TES are similarly
sensitive to δD in the free troposphere which allows one to compare their
measurements directly. At tropical latitudes where IASI's sensitivity is
lower than that of TES, we show that the agreement improves when taking into
account the sensitivity of IASI in the TES retrieval. For the comparison IASI-FTIR only direct comparisons are performed
because the sensitivity profiles of the two observing systems do not
allow to take into account their differences of sensitivity. We identify a quasi negligible
bias in the free troposphere (−3‰) between IASI retrieved δD with the TES, which
are bias corrected, but important with the ground-based FTIR reaching
−47‰. We also suggest that model-satellite observation
comparisons could be optimized with IASI thanks to its high spatial and
temporal sampling. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|