 |
| Titel |
Analysis of SMOS brightness temperature and vegetation optical depth data with coupled land surface and radiative transfer models in Southern Germany |
| VerfasserIn |
F. Schlenz, J. T. dall'Amico, W. Mauser, A. Loew |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 16, no. 10 ; Nr. 16, no. 10 (2012-10-05), S.3517-3533 |
| Datensatznummer |
250013511
|
| Publikation (Nr.) |
 copernicus.org/hess-16-3517-2012.pdf |
|
|
|
|
|
| Zusammenfassung |
| Soil Moisture and Ocean Salinity (SMOS) L1c brightness temperature and L2
optical depth data are analysed with a coupled land surface (PROMET) and
radiative transfer model (L-MEB). The coupled models are validated with
ground and airborne measurements under contrasting soil moisture, vegetation
and land surface temperature conditions during the SMOS Validation Campaign
in May and June 2010 in the SMOS test site Upper Danube Catchment in
southern Germany. The brightness temperature root-mean-squared errors are
between 6 K and 9 K. The L-MEB parameterisation is considered appropriate
under local conditions even though it might possibly be further optimised.
SMOS L1c brightness temperature data are processed and analysed in the Upper
Danube Catchment using the coupled models in 2011 and during the SMOS
Validation Campaign 2010 together with airborne L-band brightness
temperature data. Only low to fair correlations are found for this
comparison (R between 0.1–0.41). SMOS L1c brightness temperature data do not
show the expected seasonal behaviour and are positively biased. It is
concluded that RFI is responsible for a considerable part of the observed
problems in the SMOS data products in the Upper Danube Catchment. This is
consistent with the observed dry bias in the SMOS L2 soil moisture products
which can also be related to RFI. It is confirmed that the brightness
temperature data from the lower SMOS look angles and the horizontal
polarisation are less reliable. This information could be used to improve
the brightness temperature data filtering before the soil moisture
retrieval. SMOS L2 optical depth values have been compared to modelled data
and are not considered a reliable source of information about vegetation due
to missing seasonal behaviour and a very high mean value. A fairly strong
correlation between SMOS L2 soil moisture and optical depth was found (R =
0.65) even though the two variables are considered independent in the study
area. The value of coupled models as a tool for the analysis of passive
microwave remote-sensing data is demonstrated by extending this SMOS data
analysis from a few days during a field campaign to a longer term
comparison. |
| |
|
| Teil von |
|
|
|
|
|
|
|