Global-scale evaluation of two satellite-based passive microwave soil moisture datasets (SMOS and AMSR-E) with respect to Land Data Assimilation System estimates

摘要: Abstract Global Level-3 surface soil moisture (SM) maps derived from the passive microwave SMOS (Soil Moisture and Ocean Salinity) observations at L-band have recently been released. In this study, a comparative analysis of Level 3 product (referred to as SMOSL3) along with another Surface SM (SSM) Advanced Microwave Scanning Radiometer (AMSR-E) C-band is presented (this latter referred AMSRM). SM-DAS-2, SSM produced by European Centre for Medium Range Weather Forecasts (ECMWF) Land Data Assimilation System (LDAS) was used monitor both SMOSL3 AMSRM qualities. The present study carried out 03/2010 09/2011, period during which AMSR-E products were available global scale. Three statistical metrics evaluation; correlation coefficient (R), Root Mean Squared Difference (RMSD), bias. Results analysed using biomes Leaf Area Index (LAI). It shown that captured well spatio-temporal variability SM-DAS-2 most biomes. terms values, found better capture temporal dynamics in highly vegetated (“tropical humid”, “temperate etc.) while best results obtained over arid semi-arid (“desert temperate”, “desert tropical”, etc.). Finally, we showed accuracy remotely sensed strongly related LAI. Both (marginally better) correlated regions sparse vegetation values LAI ≤ 1 (these represent almost 50% pixels considered study). where LAI >1, correlations than AMSRM: had consistent performance up LAI = 6, whereas deteriorated increasing This reveals complement one monitoring wide range conditions density there are valuable satellite observed data records more 10 years, can be land–atmosphere processes.