Abstracts for the 6th International GAME Conf.

3-5 December 2004

Kyoto Japan

Seasonal Variation of Precipitation Properties Associated with Monsoon over Palau

Hisayuki Kubota (1), Ryuichi Shirooka (1), Tomoki Ushiyama (1), Takashi Chuda (1), Suginori Iwasaki (1), Kensuke Takeuchi (1)

Seasonal variation of convective activities over western Pacific regions including Palau is closely related to the Asian monsoon including Japan. However the feature of monsoon is different from that of Southeastern Asia region. Institute of Observational Research for Global Change has been conducted the observational project PALAU (Pacific Area Long-term Atmospheric observation for the Understanding of climate change) over Peleliu Island at Republic of Palau since November 2000. We focused on Peleliu station data from Jun. 2001 to Apr. 2002 and investigated the seasonal variation of precipitation properties associated with monsoon wind direction. Monsoon period is defined by 850 hPa zonal wind over Palau. Westerly wind monsoon period starts at 18 May. 2001 and easterly wind monsoon starts at 26 Nov. which dates are affected by intraseasonal oscillations. Westerly wind monsoon period: Westerly winds are prevailed and their intensities are correlated with cloud amount. Precipitable water has weak fluctuation. During convective active phase, diurnal variation of precipitation is prevailed with nocturnal maximum. On the other hand, during inactive phase afternoon maximum appeared. The properties of precipitation have strong intensity with short duration. These features resemble to that of equatorial warm pool region. Easterly wind monsoon period: Easterly winds are prevailed and are weak correlated with cloud amount. Precipitable water has large fluctuation. When dry air comes from subtropics, convection is suppressed. Averaged rainfall rate is same as westerly monsoon period. Diurnal variation of precipitation is weak. The properties of precipitations have weak intensity with long duration compared from westerly monsoon. These differences may come from the influence of subtropics.

Submittal Information

Name : Date :
    Hisayuki Kubota
    30-Jul-04-14:22:13
Organization : Theme :
    Institute of Observational Research for Global Change, Japan Agency for Marine-Earth Science and Technology (IORGC JAMSTEC)
    Theme 3
Address : Presentation :
    2-15 Natsushima-cho, Yokosuka, Kanagawa, 237-0061
    Poster or oral
Country : Abstract ID :
    Japan
    T3HK30Jul04142213
Phone : Fax :
    81-46-867-9823
    81-46-867-9835
E-mail :
    kubota@jamstec.go.jp