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

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Atmosphere Dynamic Analysis of Hail and Whirl Wind in Cianjur Regency, West Java (Case Study November 07, 2016)
Adelina Lumban Gaol

Last modified: 2017-07-24


Abstract. Natural disasters due to extreme weather have a significant impact on the society, one of them is in Bojongicung sub-regency, Cianjur regency, West Java. Whirl wind 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 shape structure with a very low cloud top temperature condition of -80 oC through analysis of Himawari-8 WV 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 whirl wind phenomena.