Microphysical Processes of Melting Snowflakes Detected by Two-wavelength Radar

[摘要] Microphysical processes in the melting layer were studied using two-wavelength radar observation.Dependence of microwave scattering by precipitation particles on radar wavelength was utilized applying the model calculations shown in Part I of Yokoyama and Tanaka (1984). The observation was performed from the end of June to the begining of July, 1979 (rainy season in Japan) using C-band (5.6cm) and X-band (3.2cm) radars. It is clearly found from the results of the observation that coalescence processes are predominant in the upperhalf region of the melting layer as was already expected by the model calculation in Part-I. How predominant the coalescence processes in the melting layer are depends on precipitation types, that is, the coalescence processes in the precipitation associated with stratiform and stationary clouds are more predominant than with cellular clouds. The effects of evaporation was also found when the atmosphere was dry around the melting layer. In the lowerhalf region of the melting layer, it was difficult to detect the microphysical processes when we use C- and X-hand radars.

[学科分类] 大气科学