Observation on Microphysical Processes in the Stratiform Precipitations Including Melting Layers at Mt. Fuji

Abstract

In order to investigate microphysical processes in the stratiform precipitations including melting layers, size distributions of the precipitation particles were measured by "filterpapers method" at three observational stations with different altitude on Mt. Fuji. The following conclusions on the microphysical processes in the stratiform precipitations were obtained inspecting the time variations of the size distribution at each station: i) In the upper part of the melting layer, small sized snowflakes (melted diameter<0.1cm) were predominant in volume and number. ii) In the middle part of the melting layer, melting and growth due to coalescence of the melting snowflakes seem to have occurred simultaneously, and the large sized particles(>0.2cm) were found frequently. iii) In the lower part and just below the melting layer, precipitation particles had finished melting. The large sized particles decreased in volume and number perhaps due to breakup and therefore the medium sized particles (0.1-0.2cm) were predominant. iv) The vertical change of the size distribution of raindrops was insignificant far below the melting layer.