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| Titel |
A soil moisture and temperature network for SMOS validation in Western Denmark |
| VerfasserIn |
S. Bircher, N. Skou, K. H. Jensen, J. P. Walker, L. Rasmussen |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 16, no. 5 ; Nr. 16, no. 5 (2012-05-16), S.1445-1463 |
| Datensatznummer |
250013299
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| Publikation (Nr.) |
 copernicus.org/hess-16-1445-2012.pdf |
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| Zusammenfassung |
| The Soil Moisture and Ocean Salinity Mission (SMOS) acquires surface soil
moisture data of global coverage every three days. Product validation for a
range of climate and environmental conditions across continents is a crucial
step. For this purpose, a soil moisture and soil temperature sensor network
was established in the Skjern River Catchment, Denmark. The objectives of
this article are to describe a method to implement a network suited for SMOS
validation, and to present sample data collected by the network to verify the
approach. The design phase included (1) selection of a single SMOS pixel
(44 × 44 km), which is representative of the land surface
conditions of the catchment and with minimal impact from open water
(2) arrangement of three network clusters along the precipitation gradient,
and (3) distribution of the stations according to respective fractions of
classes representing the prevailing environmental conditions. Overall,
measured moisture and temperature patterns could be related to the respective
land cover and soil conditions. Texture-dependency of the 0–5 cm soil
moisture measurements was demonstrated. Regional differences in 0–5 cm soil
moisture, temperature and precipitation between the north-east and south-west
were found to be small. A first comparison between the 0–5 cm network
averages and the SMOS soil moisture (level 2) product is in range with
worldwide validation results, showing comparable trends for SMOS retrieved
soil moisture (R2 of 0.49) as well as initial soil moisture and
temperature from ECMWF used in the retrieval algorithm (R2 of 0.67 and
0.97, respectively). While retrieved/initial SMOS soil moisture indicate
significant under-/overestimation of the network data (biases of
−0.092/0.057 m3 m−3), the initial temperature is in good
agreement (bias of −0.2 °C). Based on these findings, the network
performs according to expectations and proves to be well-suited for its
purpose. The discrepancies between network and SMOS soil moisture will be
subject of subsequent studies. |
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