UPSCALING SPARSE GROUND-BASED SOIL MOISTURE OBSERVATIONS FOR THE VALIDATION OF COARSE-RESOLUTION SATELLITE SOIL MOISTURE PRODUCTS uri icon

abstract

  • The contrast between the pointscale nature of current groundbased soil moisture instrumentation and the ground resolution (typically >102 km2) of satellites used to retrieve soil moisture poses a significant challenge for the validation of data products from current and upcoming soil moisture satellite missions. Given typical levels of observed spatial variability in soil moisture fields, this mismatch confounds mission validation goals by introducing significant sampling uncertainty in footprintscale soil moisture estimates obtained from sparse groundbased observations. During validation activities based on comparisons between ground observations and satellite retrievals, this sampling error can be misattributed to retrieval uncertainty and spuriously degrade the perceived accuracy of satellite soil moisture products. This review paper describes the magnitude of the soil moisture upscaling problem and measurement density requirements for groundbased soil moisture networks. Since many largescale networks do not meet these requirements, it also summarizes a number of existing soil moisture upscaling strategies which may reduce the detrimental impact of spatial sampling errors on the reliability of satellite soil moisture validation using spatially sparse groundbased observations.

published proceedings

  • REVIEWS OF GEOPHYSICS

author list (cited authors)

  • Crow, W. T., Berg, A. A., Cosh, M. H., Loew, A., Mohanty, B. P., Panciera, R., ... Walker, J. P.

complete list of authors

  • Crow, Wade T||Berg, Aaron A||Cosh, Michael H||Loew, Alexander||Mohanty, Binayak P||Panciera, Rocco||de Rosnay, Patricia||Ryu, Dongryeol||Walker, Jeffrey P