Reforming the force-restore method for predicting ground surface temperature

A reformed force-restore version that predicts exact values for ground surface temperature under a multifrequency surface forcing is developed. In developing such a version, the ground surface temperature is expanded into a Fourier series. A force-restore equation is proposed for each term in the series in terms of two unknown coefficients: forcing coefficient and restoring coefficient. Eliminating the errors in the predictions of each force-restore equation is employed in deriving explicit expressions for those coefficients. As an illustration for the applications of the reformed force-restore version, its predictions are used in evaluating the performance of a surface heat flux model and in investigating the validity range of a soil microwave radiometry model.