Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/2010
Publication Date: 4/5/2010
Citation: Crow, W.T., Reichle, R., Koster, R., Kimball, J. 2010. The SMAP Level 4 surface and root-zone soil moisture product [abstract]. Online Proceedings of the NASA Terrestrial Ecology Program Workshop. 2010 CDROM. Interpretive Summary:
Technical Abstract: Slated for launch in 2015, the NASA Soil Moisture Active/Passive mission represents a generational advance in our ability to globally observe time and space variations in surface soil moisture fields. The SMAP mission concept is based on the integrated use of L-band active radar and passive radiometry measurements to optimize both the accuracy and resolution of remotely-sensed soil moisture estimates. Data assimilation activities represent a critical linkage between SMAP products and eventual science and operational applications. In particular, SMAP mission plans call for the generation of a dedicated data assimilation product to vertically extrapolate near-surface (0 to 5-cm) soil moisture retrievals to produce deeper, root-zone (0 to 1-m) soil moisture estimates required by agricultural and ecological productivity applications. To meet this goal, a global Ensemble Kalman filtering (EnKF) land data assimilation system capable of SMAP observations with a vertically-discretized land surface model is currently under development at the NASA Global Modeling and Assimilation Office (GMAO). This system will be used to generate an official Level 4 SMAP ?surface and root-zone? (L4_SM) soil moisture product. The use of data assimilation techniques to generate an official mission product is highly unusual for a NASA earth science mission and represents an important milestone in the application of land data assimilation to terrestrial remote sensing mission design. This poster will describe the SMAP L4_SM surface and root-zone soil moisture system in detail and summarize recent Observing System Simulation Experiment (OSSE) activities aimed at quantifying the added value of SMAP soil moisture retrievals for global root-zone soil moisture monitoring activities. Existing applications already possess access to soil moisture estimates derived from off-line water balance models constrained solely by observed rainfall and meteorological variables. Clarifying the added benefit of assimilating remotely-sensed surface soil moisture retrievals into such systems (relative to this existing baseline) is critical for articulating expected SMAP impacts on key applications.