Temporal coverage: 31 March 2015 - present
The Soil Moisture Active Passive (SMAP) “Surface Soil Moisture 9 km (L4, 12z Instantaneous, Model Value-Added)” layer displays model-derived global surface soil moisture of the top 5 cm of the soil column in m3/m3 posted on a 9 km EASE-Grid 2.0. Surface soil moisture estimates are obtained by merging SMAP observations with estimates from a land surface model in a soil moisture ensemble Kalman filter data assimilation system. 12z indicates the Z (or UTC) time used for nearest 3-hourly analysis time when SMAP observations are merged into the assimilation system.
The SMAP spacecraft carries two instruments, a radar (active) and a radiometer (passive), that together make global measurements of land surface soil moisture and freeze/thaw state. It is useful for monitoring and predicting natural hazards such as floods and droughts, understanding the linkages between Earth’s water, energy and carbon cycles, and reducing uncertainties in predicting weather and climate.
References: SMAP L4 9 km EASE-Grid Surface and Root Zone Soil Moisture Analysis Update
Data field: sm_surface_analysis
Temporal coverage: 31 March 2015 - present
The Soil Moisture Active Passive (SMAP) “Surface Soil Moisture 9 km Uncertainty (L4, 12z Instantaneous, Model Value-Added)” layer displays uncertainty estimates of model-derived global surface soil moisture of the top 5 cm of the soil column in m3/m3 posted on a 9 km EASE-Grid 2.0. Surface soil moisture estimates are obtained by merging SMAP observations with estimates from a land surface model in a soil moisture ensemble Kalman filter data assimilation system. Error estimates are derived from the ensemble standard deviation of the analyzed fields.
The SMAP spacecraft carries two instruments, a radar (active) and a radiometer (passive), that together make global measurements of land surface soil moisture and freeze/thaw state. It is useful for monitoring and predicting natural hazards such as floods and droughts, understanding the linkages between Earth’s water, energy and carbon cycles, and reducing uncertainties in predicting weather and climate.
References: SMAP L4 9 km EASE-Grid Surface and Root Zone Soil Moisture Analysis Update
Data field: sm_surface_analysis_ensstd