Intraseasonal variation of raindrop size distribution at Koto Tabang, West Sumatra, Indonesia
Intraseasonal variation of raindrop size distribution at Koto Tabang, West Sumatra, Indonesia
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DOI：
10.1029/2004gl022340
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发表时间：
2005-04
影响因子：
5.2
通讯作者：
T. Kozu;T. Shimomai;Zainul Akramin;Marzuki;Y. Shibagaki;H. Hashiguchi
中科院分区：
文献类型：
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作者：
T. Kozu;T. Shimomai;Zainul Akramin;Marzuki;Y. Shibagaki;H. Hashiguchi
利用位于苏门答腊岛西部Koto Tabang的2D视频仪(2DVD)、边界层雷达(BLR)和赤道大气雷达，以及GOES-9红外亮温，研究了雨滴尺寸分布(DSD)对Madden Julian振荡(MJO)的响应的季节内变化。采用马歇尔-帕尔默(Δ-Palmer，MP)雷达反射率(Z)-雨率(R)关系式的雷达反射率(Z)与雨率(R)之间的差值(Z=200R1.6)作为DSD的参数。研究发现，在MJO的非活动期，2DVD衍生的ΔZMP一般为正值，表明DSD较宽，但随着MJO位相向活动期的转变，DSD逐渐减小到负值。从BLR得到的雨顶高度表明，非活动MJO位相的对流过程比活动位相的对流过程更强烈，这将导致DSD的差异。
Intraseasonal variation of raindrop size distribution (DSD) in response to Madden Julian Oscillation (MJO) is studied using a 2D video disdrometer (2DVD), a boundary layer radar (BLR) and the Equatorial Atmosphere Radar, operated at Koto Tabang, west Sumatra, as well as GOES‐9 infra‐red brightness temperature. As a parameter of DSD, ΔZMP, which is defined as the difference between a measured radar reflectivity in dB and that from the Marshall‐Palmer (MP) radar reflectivity (Z) ‐ rain rate (R) relationship, Z = 200 R1.6, is used. It is found that in non‐active phase of MJO, 2DVD‐derived ΔZMPs are generally positive, indicating that DSDs are broad, while they decrease toward negative values as the phase of MJO shifts to active ones. Rain‐top height derived from the BLR indicates that the convective processes are more intense in the non‐active MJO phase than in the active phase, which would cause the difference in DSDs.