Numerical study of multi-frequency dual-polarization microwave radiometry technique for supercooled liquid water detection

Multi-frequency brightness temperature (T_B) simulations for liquid and mixed phase clouds are shown. The maximum particle size in the cloud layer is assumed to be smaller than 1 mm and liquid particle size is an order of magnitude smaller than the ice particle. It is shown that the difference in T_B at linear polarization (ΔT_B) is sensitive to the frequency and mean particle size. It will be difficult to detect a mixed phase cloud using ΔT _B. A physically based method for detecting mixed phase cloud that uses T_B measurement at 20, 30, and 90 or 150 GHz is described. Preliminary model calculation suggests T_B measurement 150 GHz is more sensitive to mixed phase cloud detection