 |
| Titel |
Improving 2D tomography for trace gas retrievals combining SCIAMACHY limb and nadir measurements |
| VerfasserIn |
Janis Pukite, Sven Kühl, Tim Deutschmann, Steffen Beirle, Patrick Jöckel, Steffen Dörner, Thomas Wagner |
| Konferenz |
EGU General Assembly 2011
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250052744
|
|
|
|
|
|
| Zusammenfassung |
| The Scanning Imaging Absorption spectroMeter for Atmospheric CHartographY
(SCIAMACHY) on the ENVISAT satellite probes the atmosphere at the day side of Earth in
alternating sequences of nadir and limb measurements, i.e., looking nearly perpendicularly
and tangentially to the Earth’s surface, respectively.
Limb measurements allow retrieving stratospheric profiles of various trace gases on a
global scale. Combining measurements of the same air volume from different viewing
positions along the orbit, a tomographic approach can be applied and 2D distribution fields of
stratospheric trace gases can be acquired in one inversion.
With this approach, it is possible to improve the treatment for the effect of the
horizontal gradients in the trace gas distribution on the profile retrieval. This was
shown in previous studies (1) for the retrieval of NO2 and OClO profiles in the
Arctic region near the polar vortex boundary in January and (2) globally for NO2
on measurements during special “limb-only” orbits performed on 14 December
2008.
In this study, a possibility to include also the information from the nadir observations in
the tomographic profile retrieval approach is shown. This has a potential to improve the
retrieval for the first limb measurement sequence of a SCIAMACHY orbit where, due to no
preceding limb scanning sequence, only the nadir measurements allow to estimate the
gradient. An improvement can be obtained also along the remaining part of the nominal
SCIAMACHY orbits for which, due to nadir measurements performed in between limb
scanning sequences, the coarse spatial overlap of the limb measurements is limiting
tomographic capabilities. The improvement is investigated for simulated scenarios and case
studies on real measurements. |
|
|
|
|
|
|