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Titel |
Long term soil moisture mapping over the Tibetan plateau using Special Sensor Microwave/Imager |
VerfasserIn |
R. Velde, M. S. Salama, T. Pellarin, M. Ofwono, Y. Ma, Z. Su |
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 ; 18, no. 4 ; Nr. 18, no. 4 (2014-04-04), S.1323-1337 |
Datensatznummer |
250120325
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Publikation (Nr.) |
copernicus.org/hess-18-1323-2014.pdf |
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Zusammenfassung |
This paper discusses soil moisture retrievals over the Tibetan Plateau from
brightness temperature (TB's) observed by the Special Sensor Microwave
Imagers (SSM/I's) during the warm seasons of the period from July 1987 to
December 2008. The Fundamental Climate Data Record (FCDR) of F08, F11 and
F13 SSM/I satellites by the Precipitation Research Group of Colorado State
University is used for this study. A soil moisture retrieval algorithm is
developed based on a radiative transfer model that simulates
top-of-atmosphere TB's whereby effects of atmosphere are calculated from
near-surface forcings obtained from a bias-corrected dataset. Validation of
SSM/I retrievals against in situ measurements for a two-and-half year period
(225 matchups) gives a Root Mean Squared Error of 0.046 m3 m−3.
The agreement between retrievals and Noah simulations from the Global Land
Data Assimilation System is investigated to further provide confidence in
the reliability of SSM/I retrievals at the Plateau-scale.
Normalised soil moisture anomalies (N) are computed on a warm seasonal
(May–October) and on a monthly basis to analyse the trends present within
the products available from July 1987 to December 2008. The slope of linear
regression functions between N and time is used to quantify the trends. Both
the warm season and monthly N indicate severe wettings of 0.8 to almost 1.6
decade−1 in the centre of the Plateau. Correlations are found by the
trend with elevation for the warm season as a whole and the individual
months May, September and October. The observed wetting of the Tibetan
Plateau agrees with recent findings on permafrost retreat, precipitation
increase and potential evapotranspiration decline. |
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