A coupled force-restore model of surface temperature and soil moisture using the maximum entropy production model of heat fluxes

A coupled force-restore model of surface soil temperature and moisture (FRMEP) is formulated by incorporating the maximum entropy production model of surface heat fluxes and including the gravitational drainage term. The FRMEP model driven by surface net radiation and precipitation are independent of near-surface atmospheric variables with reduced sensitivity to the uncertainties of model input and parameters compared to the classical force-restore models (FRM). The FRMEP model was evaluated using observations from two field experiments with contrasting soil moisture conditions. The modeling errors of the FRMEP predicted surface temperature and soil moisture are lower than those of the classical FRMs forced by observed or bulk formula based surface heat fluxes (bias 1 similar to 2 degrees C versus similar to 4 degrees C, 0.02m(3)m(-3) versus 0.05m(3)m(-3)). The diurnal variations of surface temperature, soil moisture, and surface heat fluxes are well captured by the FRMEP model measured by the high correlations between the model predictions and observations (r0.84). Our analysis suggests that the drainage term cannot be neglected under wet soil condition. A 1year simulation indicates that the FRMEP model captures the seasonal variation of surface temperature and soil moisture with bias less than 2 degrees C and 0.01m(3)m(-3) and correlation coefficients of 0.93 and 0.9 with observations, respectively.