Modeling of the melting layer. Part II: Electromagnetic

Abstract

To complement the meteorological modeling of the melting layer, a model of the scattering properties at microwave frequencies for snow, melting snow, and rain is implemented. The scattering model, running in tandem with a meteorological model, generates the reflectivity fields associated with the hydrometeors in the model to facilitate comparisons with available observations. Several existing and a few new approaches for the scattering of melting snow are attempted. In addition, the models are run using several relationships for the density of snowflakes as a function of their size. A large variability in the prediction of the brightband intensity is observed as a function of the scattering model. However, the scattering model whose melting snow morphology resembles most the one of real snowflakes reproduces the available observations with the highest accuracy. Sensitivity to the snowflake density relationship used is found to be less important. Other features like the melting-layer thickness, brightband peak position, and Doppler velocity are also correctly predicted.