SIZE DISTRIBUTION OF HYDROMETEORS THROUGH THE MELTING LAYER

Hydrometeor size and velocity distributions and particle number flux d ensities are measured with an optical spectrometer within the melting layer of stratiform precipitation. These data are compared to raindrop size measurements with a disdrometer below the melting layer. Compari ng the hydrometeor number flux densities, the following conclusions ca n be made: the number flux density of snowflakes just above the meltin g layer corresponds 1:1 to the number flux density of raindrops just b elow the melting layer. Furthermore, strong evidence is found for aggr egation of hydrometeors within the upper part of the melting layer and breakup within the lower part. (C) 1998 Elsevier Science B.V. All rig hts reserved.