Evaluation of SMAP, SMOS, and AMSR2 soil moisture retrievals against observations from two networks on the Tibetan Plateau. Issue 11 (10th June 2017)

• Record Type: Journal Article
• Authors: Chen, Yingying; Yang, Kun; Qin, Jun; Cui, Qian; Lu, Hui; La, Zhu; Han, Menglei; Tang, Wenjun
• Is Part Of: Journal of geophysical research. Volume 122:Issue 11(2017)
• Page Start: 5780
• Page End: 5792
• Publication Date: 2017-06-10
• Subjects: satellite soil moisture products -- soil moisture networks -- Tibetan Plateau -- evaluation; Atmospheric physics -- Periodicals; Geophysics -- Periodicals; 551.5
• DOI: 10.1002/2016JD026388
• Languages: English
• ISSNs: 2169-897X

Abstract

Abstract: Two soil moisture and temperature monitoring networks were established in the Tibetan Plateau (TP) during recent years. One is located in a semihumid area (Naqu) of central TP and consists of 56 soil moisture and temperature measurement (SMTM) stations, the other is located in a semiarid area (Pali) of southern TP and consists of 21 SMTM stations. In this study, the station data are used to evaluate soil moisture retrievals from three microwave satellites, i.e., the Soil Moisture Active Passive (SMAP) of NASA, the Soil Moisture and Ocean Salinity (SMOS) of European Space Agency, and the Advanced Microwave Scanning Radiometer 2 (AMSR2) of Japan Aerospace Exploration Agency. It is found that the SMAP retrievals tend to underestimate soil moisture in the two TP networks, mainly due to the negative biases in the effective soil temperature that is derived from a climate model. However, the SMAP product well captures the amplitude and temporal variation of the soil moisture. The SMOS product performs well in Naqu network with acceptable error metrics but fails to capture the temporal variation of soil moisture in Pali network. The AMSR2 products evidently exaggerate the temporal variation of soil moisture in Naqu network but dampen it in Pali network, suggesting its retrieval algorithm needs further improvements for the TP. Key Points: Measurements from two dense networks on the Tibetan Plateau are used to evaluate three operational satellite soil moisture products SMAP retrievals underestimate soil moisture but well capture its dynamics on the Tibetan Plateau The underestimated effective soil temperatures may cause the underestimation of SMAP soil moisture