Seasonal and spatial variation of CAPE and occurrence of meso-scale disturbances in the South Asia
Mr.YusukeYamane (1), Dr.Taiichi Hayashi (1)
(1) Desaster Prevention Reserch Institute, Kyoto University
Severe meso-scale disturbances occur frequently in the northeastern region of the Indian subcontinent including Bangladesh. These thunderstorms are locally known as gNorfwesterh (because thunderstorms often come from north westerly direction). These disturbances are sometimes accompanied with destructive tornadoes and cause serious damages. The occurrence of these thunderstorms concentrates in the pre-monsoon season (from March to May).
The thermal stratification affects primarily for the occurrence and the development of these meso-scale disturbances. In this point, the seasonal and spatial variation of the distribution of the thermal instability is important in the Indian subcontinent. In this paper, the variation of distribution of monthly averaged CAPE (Convective Available Potential Energy) in the South Asia in 1993 is examined by ECMWF 40 Years Re-Analysis data (ERA-40). As a result, the region of the relatively higher CAPE (>2400J/kg) is found just over Bangladesh in May. The value of CAPE in May is the highest over the South Asia in 1993, which indicates that most possibility of the occurrence and the development of the severe disturbances. In April and March, the region of the relatively higher CAPE is also found over Bangladesh. However, the value is not the most highest over the South Asia in each month.
Submittal Information
Name :
Date :
Mr.Yusuke Yamane
31-Jul-04-15:21:41
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Disaster Prevention Reserch Institute, Kyoto University