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Intraseasonal variation of raindrop size distribution at Koto Tabang, West Sumatra, Indonesia
Author(s) -
Kozu Toshiaki,
Shimomai Toyoshi,
Akramin Zainul,
Shibagaki Yoshiaki,
Hashiguchi Hiroyuki
Publication year - 2005
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2004gl022340
Subject(s) - madden–julian oscillation , disdrometer , radar , atmospheric sciences , climatology , convection , environmental science , atmosphere (unit) , variation (astronomy) , brightness temperature , brightness , geology , physics , meteorology , precipitation , astrophysics , optics , telecommunications , rain gauge , computer science
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, Δ Z MP , 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 R 1.6 , is used. It is found that in non‐active phase of MJO, 2DVD‐derived Δ Z MP s 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.