Radar attenuation due to melting: a comparison of physical models proposed for the melting morphology

The radio wave attenuation through the melting layer at various frequencies is investigated. The effect of the melting morphology on the attenuation computed by the Mie theory is discussed. To obtain the rate of melting of snowflakes, a melting model is given. In this model, the six different patterns proposed by Fabry and Szyrmer [J. Atmos. Sci., 56 (1999) 3593] to calculate the permittivity of the melting particles are used and the specific attenuation for each morphology is obtained. A comparison between the computed specific attenuation computed for the frequencies 2.8, 9.4 and 22.2 GHz is made. This analysis suggests that the large variability in the specific attenuation given by these models is due to the melting morphology in which the melting snow is modeled as a snow sphere surrounded by a water shell.