UNS Conference Portal, The 1st International Conference on Science, Mathematics, Environment and Education 2017

Font Size: 
ATMOSPHERE DYNAMIC ANALYSIS OF HAIL AND MINI TWISTER IN DISTRICT CIANJUR, WEST JAVA (CASE STUDY 07 NOVEMBER 2016)
Adelina Lumban Gaol

Last modified: 2017-07-05

Abstract


Natural disasters due to extreme weather have a significant impact on the society, one of them is in Bojongicung sub-district, Cianjur regency, West Java. Mini twister and hail events have been recorded causing environmental damage and material loss on November 7, 2016 ago. Interestingly, both of these phenomena occur at the same time with a fairly short time scale. This study identifies the existence of Cumulonimbus cloud composite forming a bow echo structure with a very high cloud peak temperature condition of -80 oC through analysis of Himawari-8 IR channel images by using SATAID software. Surface weather observation data such as air temperature, surface moisture, and air pressure also support extreme weather events. Radiosonde data analysis using the LI index (Lifting Index), TT (Total Total), KI (K Index), CAPE (Convective Available Potential Energy), and BRN (Bulk-Richardson Number) indicate the movement of rising air masses and atmosphere instability providing an opportunity for convective cloud formation. In addition, the results of GrADS analysis using ECMWF reanalysis data in the form of streamline detecting wind patterns with convergence activity and positive value of relative vorticity indicates a movement of vertical air mass at layer of 1000 mb up to layer of 200 mb. This also contributes to the formation of hail and mini twister phenomena.