HR: 1340h
AN: A43B-1138    [Abstracts]
TI: The Rainfall Phenomena during the Pre-Monsoon Period over the Northeastern Part of Indian Subcontinent in 2007
AU: * Kiguchi, M
EM: kiguchi@iis.u-tokyo.ac.jp
AF: the Univ. of Tokyo, Japan, 4-6-1, Komaba, Meguro-ku, Tokyo, 1538505, Japan
AU: Yamane, Y
AF: Kyoto Univ., Japan, Gokasho, Uji, 6110011, Japan
AU: Eguchi, N
AF: National Institute for Environmental Studies, Japan, 16-2, Onogawa, Tsukuba, 3058506, Japan
AU: Murata, F
AF: Kochi Univ., Japan, 2-5-1, Akebono-cho, Kochi, 7808520, Japan
AU: Terao, T
AF: Kagawa Univ., Japan, 1-1, Saiwai-cho, Takamatsu, 7608522, Japan
AU: Hayashi, T
AF: Kyoto Univ., Japan, Gokasho, Uji, 6110011, Japan
AU: Karmakar, S
AF: Bangladesh Meteorological Department, Bangladesh, Agargaon, Dhaka, 1207, Bangladesh
AB: The rainfall phenomena during the pre-monsoon period over the northeastern part of Indian subcontinent in 2007 are investigated using OLR and the NCEP/NCAR reanalysis data during the period from March to May in 2007. Moreover, for the purpose of clarifying the atmospheric condition and the structure of the disturbance during the pre-monsoon period, we carried out the upper air observation at Dhaka in Bangladesh during the period from 20 April to 15 May in 2007. The time series of OLR over Bangladesh (22.5--27.5 ° N, 87.5--92.5 ° E) from March to May in 2007 is calculated. It is well known that an average monsoon onset over Bangladesh occurs in early June [e.g., Ahmed and Karmakar, 1993; Wang and LinHo, 2002]. In March, the convection activity becomes suppressed. During the IOP, we can divide it into 3 stages (A: 20--27 April, B: 28 April -- 5 May, C: 6--14 May) by the OLR value indicated the convective activity. During stages A and C, there is comparatively convection activity. On the other hand, and the convection activity become suppressed during stage B. Actually, the mesoscale disturbance activity with a dead person is active in A. Although the convective activity during spell C is active, there was little rainfall by the ground observation. We carried out that the composite analysis of OLR about each period in stage A, B, and C. It is shown that the lower OLR region goes southward from the middle latitude in stage A. In addition, the lower OLR region of the southern part of the Indochina Peninsula goes northwestward from stage A to C. It is suggested that the eastward moving and passage of the trough of the upper air along the south slope of the Tibetan plateau brought the rainfall phenomena during the pre-monsoon period. The northeastern part of Indian subcontinent during the pre-monsoon period is affected by the middle latitude.
DE: 3309 Climatology (1616, 1620, 3305, 4215, 8408)
DE: 3329 Mesoscale meteorology
DE: 3354 Precipitation (1854)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting