Reanalysis of L-band brightness predicted by the LSP/R model for prairie grassland: Incorporation of rough surface scattering

L-band brightness predicted by the land surface process/radiobrightness (LS P/R) model for prairie grassland appears to be somewhat lower than expected El], A crucial reason for the underestimate of the L-band brightness is th at the soil surface was treated as smooth. In this paper, surface scatterin g of the soil determined by the IEM model is incorporated into the LSP/R mo del to examine its impact on the predicted L-band brightness. Eight sets of surface parameters, two correlation lengths (L) of 3 and 6 cm x 4 root mea n squared (RMS) heights (a) of 0.3,0.6, 0.8, and 1.0 m, are utilized to cha racterize the emission of the soil surface. It is found that II-polarized, L-band brightness is expectedly increased by different levels for all of th e eight rough surface Eases compared to the smooth surface Ease. The increa se in the average of the Ii-polarized, L-band brightness is by as much as 1 3.2 K for the case with L = 3 cm and a = 1.0 cm, In addition, L-band's sens itivity to soil moisture is found to be approximately equal with and withou t the scattering effects. An increase in II-polarized, L-band brightness by about 12 K at the end of a 14-day simulation by the LSP/R model is in resp onse to a decrease in soil moisture by 7% for all of the nine cases of conc ern (eight rough plus one smooth soil surfaces).