Summary
International Symposium on Antennas and Propagation
2006
Session Number:3B1a
Session:
Number:3B1a-3
Raindrop Size Distributions of Tropical Precipitation over West Sumatera
Marzuki, Toshiaki Kozu, Toyoshi Shimomai,
pp.1-6
Publication Date:2006/11/2
Online ISSN:2188-5079
Summary:
Raindrop size distribution associated with tropical rainfall at Koto Tabang (KT) in West Sumatera of Indonesia have been measured by a two dimensional video disdrometer (2DVD) during March to May 2004. The Wadvogel No jump is clearly observed in some rain events at KT. However, single No-R relation based on No jump is not applicable to classify precipitation at KT. This finding may clarify the previous studies which stated that the diurnal and intraseasonal variation of DSD was clearly observed at KT. Therefore, a rain classification based on a simple threshold of rain rate is used as a preliminary method in this study. The intercept A of Z-R relation (Z = ARb) found for KT precipitation in this study is smaller than those in previous studies of tropical precipitation in other climatic regions. Analysis of averaged DSD spectra for convective and stratiform rain shows that the precipitation at Koto Tabang is associated with many small drops in which stratiform DSD spectra is more concave-down than that of convective. Besides many small drops, there is also an increase in the number of large drops in convective, indicated by increasing Do. This result is consistent with the analysis of rain rate dependent of DSDs in which two parameters of both gamma and exponential distribution (No, λ) decrease with increasing rain rate, indicating an increase of large drop in increasing rain rate as also shown from Do.