Vertical structure of radar reflectivity and winds (especially vertical velocity) within the precipitation systems moving over Mt. Jiri was examined. For comparing with retrieved vertical velocities, we developed a technique to derive vertical velocities from fall velocity and drop size spectra measured by the Parsivel disdrometers. From the comparison of vertical velocities between the Parsivel and anemometer, we found that upward motions were dominant in the windward side and the areas of upward motions were nearly coincident to those of a large amount of rainfall accumulation. During the periods of updrafts, rainfall rates and mean drop diameter were larger than those during the periods of downdrafts. We digitized these updraft periods as percentage, dividing them by the total rainfall period and these percentage values would be useful for inducing an area of updrafts around the mountain. Also, variances of Parsivel-measured fall velocities per each diameter bin, which are related to turbulent air intensity, were found to be larger when surface winds were stronger.
This work was financially supported by the Development and application of Cross governmental dual-pol. Radar harmonization (WRC-2013-A-1) and the BK21 plus Project of the Graduate School of Earth Environmental Hazard System.