Abstracts for the 5th International GAME Conf.

3-5 October 2001

Aichi Trade Center

Nagoya Japan

Relationship between wind and precipitation observed with a UHF radar, GPS rawinsondes and surface meteorological instruments at Kototabang, West Sumatera during September-October 1998

Eddy Kelana (10), Fumie Murata (1), Shin-Ya Ogino (1), Manabu. D. Yamanaka (3), Masatomo Fujiwara (4), Hiroyuki Hashiguchi (5), Shoichiro Fukao (5), Mahally Kudsy (7), Tien Sribimawati (7), Sri Woro B. Harijono (7)

Simultaneous observations with a UHF-band boundary layer radar (hereafter referred as BLR), GPS rawinsondes and a tipping-bucket-type rain gauge were conducted at Kototabang (0.20 deg. S, 100.32 deg. E, 865 m MSL), which is located on the mountainous region near Bukittinggi, West Sumatera Province, during 27 September--7 October 1998 (rainy season). Low-level (1--3 km) westerly wind stronger than 10 m/s was observed, and precipitation tended to occur when the low-level westerly wind became weak (2--5 October). Similar relationship was observed for two months (1 September--31 October 1998) during which only BLR and surface meteorological instruments were operated at Kototabang. NCEP/NCAR objective analysis and GMS TBB data showed that the low-level (850 hPa) wind field and cloud distribution were both completely different between the Indonesian Archipelago (the east of Kototabang) and the eastern Indian Ocean including the Bay of Bengal (the west of Kototabang) during the analysis period. Two large-scale cloud disturbances existed along the equator in the western side (80\degr --100\degr E), but precipitation at Kototabang did not correspond to these cloud disturbances. Thus, it is suggested that the mountain range of Sumatera prevented the large-scale cloud disturbances over the Indian Ocean from having influences on the atmosphere over the Indonesian Archipelago, and the precipitation by local-scale cloud systems prevailed at Kototabang. The diurnally oscillating local circulations are considered as the major cause of the local-scale cloud systems, which may be masked when the westerly wind is strong. This may lead to a mechanism to suppress equatorial disturbances over the ocean due to local disturbances generated independently by the topography.

Submittal Information

Name : Date :
    Fumie Murata
    31-May-01-16:23:55
Organization : Theme :
    Graduate School of Science and Technology, Kobe University
    Theme 1
Address : Presentation :
    1-1 Rokkodai-cho Kobe, Hyogo 657-8501
    Poster or oral
Country : Abstract ID :
    Japan
    T1FM31May01162355
Phone : Fax :
    +81 78 803 5793
    +81 78 803 5757
E-mail :
    murata@shizen.sci.kobe-u.ac.jp