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www.hydrol-earth-syst-sci-discuss.net/8/243/2011/
doi:10.5194/hessd-8-243-2011
© Author(s) 2011. This work is distributed
under the Creative Commons Attribution 3.0 License.
A plateau scale soil moisture and soil temperature observatory for quantifying uncertainties in coarse resolution satellite products
1Faculty of Geo-Information Science and Earth Observation (ITC), University of Twente, Enschede, The Netherlands
2Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences (CAREERI/CAS), Lanzhou, China
3TEL, Institute of Tibetan Plateau Research, Chinese Academy of Sciences (ITP/CAS), Beijing, China
Abstract. A plateau scale soil moisture and soil temperature observatory is established on the Tibetan Plateau for quantifying uncertainties in coarse resolution satellite products of soil moisture and soil temperature. The observatory consists of three regional networks across the Tibetan Plateau and provides reliable measurements of mean and variance in soil moisture and soil temperature of representative areas comparable in size to coarse satellite footprints. Using these in-situ measurements, a analysis is carried out to assess the reliability of several satellite products derived from AMSR-E and ASCAT data by three retrieval algorithms (henceforth the AMSR-E products, the ASCAT-L2 products and the ITC-model retrievals) for the first time. For the cold semiarid Naqu area, AMSR-E and ASCAT-L2 products overestimate significantly the regional soil moisture in the monsoon seasons. The ITC-model retrievals are closer to the in-situ measurements but the dynamics in the retrieved time series needs further investigation. The use of these datasets is therefore not recommended for cold semiarid conditions on the Tibetan Plateau. For the cold humid Maqu network area AMSR-E and ASCAT-L2 products have comparable accuracy as reported by previous studies in the humid monsoon period. AMSR-E products significantly overestimate and ASCAT-L2 products underestimate the soil moisture in the winter period. The ITC-model retrievals underestimate the soil moisture in general. It is concluded that global coarse resolution soil moisture products are useful but exhibit till now unreported uncertainties in cold and semiarid regions – use of them would be critically enhanced if uncertainties can be quantified and reduced using in-situ measurements.
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Notice on Discussion StatusCitation: Su, Z., Wen, J., Dente, L., van der Velde, R., Wang, L., Ma, Y., Yang, K., and Hu, Z.: A plateau scale soil moisture and soil temperature observatory for quantifying uncertainties in coarse resolution satellite products, Hydrol. Earth Syst. Sci. Discuss., 8, 243-276, doi:10.5194/hessd-8-243-2011, 2011. Bibtex EndNote Reference Manager XML
