SMAP Detects Soil Moisture Under Temperate Forest Canopies. Issue 19 (2nd October 2020)

• Record Type: Journal Article
• Authors: Colliander, Andreas; Cosh, Michael H.; Kelly, Vicky R.; Kraatz, Simon; Bourgeau‐Chavez, Laura; Siqueira, Paul; Roy, Alexandre; Konings, Alexandra G.; Holtzman, Natan; Misra, Sidharth; Entekhabi, Dara; O'Neill, Peggy; Yueh, Simon H.
• Is Part Of: Geophysical research letters. Volume 47:Issue 19(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-10-02
• Subjects: soil moisture -- forest -- SMAP -- remote sensing; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2020GL089697
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Soil moisture dynamics in the presence of dense vegetation canopies are determinants of ecosystem function and biogeochemical cycles, but the capability of existing spaceborne sensors to support reliable and useful estimates is not known. New results from a recently initiated field experiment in the northeast United States show that the National Aeronautics and Space Administration (NASA) SMAP (Soil Moisture Active Passive) satellite is capable of retrieving soil moisture under temperate forest canopies. We present an analysis demonstrating that a parameterized emission model with the SMAP morning overpass brightness temperature resulted in a RMSD (root‐mean‐square difference) range of 0.047–0.057 m 3 /m 3 and a Pearson correlation range of 0.75–0.85 depending on the experiment location and the SMAP polarization. The inversion approach included a minimal amount of ancillary data. This result demonstrates unequivocally that spaceborne L‐band radiometry is sensitive to soil moisture under temperate forest canopies, which has been uncertain because of lack of representative reference data. Key Points: Soil moisture monitoring networks were deployed at two forested sites for SMAP validation experiment SMAP brightness temperature was used to retrieve soil moisture over predominantly forested sites The study demonstrates the capability of spaceborne L‐band radiometry to retrieve soil moisture under forest canopies