Estimating rootzone soil moisture by assimilating both microwave based surface soil moisture and thermal based soil moisture proxy observations

Authors: Li, Fuqin; Crow, Wade

Submitted to: American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: 11/30/2007
Publication Date: 12/12/2007
Citation: Li, F., Crow, W.T. 2007. Estimating rootzone soil moisture by assimilating both microwave based surface soil moisture and thermal based soil moisture proxy observations [abstract]. 2007 Fall Meeting American Geophysical Union. 2007 CDROM.

Interpretive Summary:

Technical Abstract: A number of synthetic data assimilation experiments are carried out at the USDA Economic and Environmental Enhancement (OPE3) site in Beltsville, Maryland. As a first case, only surface soil moisture retrievals are assimilated into a land surface model using the Ensemble Kalman filter (EnKF). This case is compared to dual EnKF assimilation results where both surface and root-zone soil moisture observations (derived from thermal remote sensing observations) are simultaneously assimilated. The ability of the dual assimilation case to enhance results (relative to the single surface soil moisture assimilation case) is examined for a range of root-zone soil moisture accuracies and frequencies to determine how valuable root-zone moisture retrievals-degraded to realistic levers of frequency and accuracy-are for the accurate constraint of land surface model predictions. Problems associated with the low temporal frequency of thermal remote sensing data, the accurate specification of modeling uncertainties within the EnKF, and the nonlinearity of the land surface model with respect to soil moisture will be discussed. Preliminary results for the assimilation of real observations at the OPE3 side will also be presented.