Compared performances of microwave passive soil moisture retrievals (SMOS) and active soil moisture retrievals (ASCAT) using land surface model estimates (MERRA-LAND)

摘要: Performances of two global satellite-based surface soil moisture (SSM) retrievals with respect to model-based SSM derived from the MERRA (Modern-Era Retrospective analysis for Research and Applications) rea-nalysis were explored in this paper: (i) Soil Moisture Ocean Salinity (SMOS; passive) Level-3 (SMOSL3) (ii) Advanced Scatterometer (ASCAT; active) SSM. Temporal correlation was used investigate performance SMOSL3 ASCAT products during period 05/2010-2012 on a basis. Both (slightly better) captured well (R>0.70) long-term variability modelled SSM, particularly, over Indian subcontinent, Great Plains North America, Sahel. However, had negative correlations arid regions, particular across Sahara Arabian Peninsula. This may be due complex scattering mechanisms very dry surfaces. To explore land cover dependence analyzed statistical indicators, results averaged per biome extracted map biomes. In general, performances behaved differently one another. For SMOSL3, highest average observed “tropical semi-arid” (R = ~ 0.5) “temperate biomes, whereas ASCAT, 0.7) humid” The poorest agreement both generally found “tundra” “desert temperate” particularly ASCAT. study showed that is highly dependent vegetation. We also them provide complementary information which implies potential data fusion would pertinent ESA climate change initiative (CCI).