MEASUREMENTS OF MELTING LAYER ATTENUATION AT X-BAND FREQUENCIES

The attenuation at X band caused by the melting layer of stratiform pr ecipitation is derived by comparing long-term average reflectivity pro files from collocated X-band and UHF vertically pointing radars. The t otal attenuation caused by the bright band is equivalent to the attenu ation across approximately 10 km of rain that is present below it. Thi s bright band attenuation is still 3-5 times the ''rain equivalent'' a ttenuation, the latter being obtained by integrating the specific atte nuation deduced from the entire reflectivity profile across the bright band as if the reflectivity were due to rain. This suggests that in m ost stratiform rain cases, the total attenuation due to the melting la yer exceeds that of the rain below it.