Identifikasi Sebaran Abu Vulkanik dan Analisis Profil Vertikal Stabilitas Atmosfer Pasca Erupsi Gunung Marapi Desember 2023

Abstract

On December 3, 2023 at 2:52 pm there was an eruption of Mount Marapi, which is located between Agam Regency and Tanah Datar Regency, West Sumatra. At the time of the eruption the mountain was at level II or alert status. Eruptions release various volcanic substances which then enter the atmosphere which affect atmospheric stability. Atmospheric stability index is one of the parameters that can be generated from Radiosonde data processing. There is a relationship between the atmospheric stability index and volcanic eruptions. This research was conducted with descriptive analytical method using sounding analysis of TEMP password data from Minangkabau Meteorological Station to produce upper air parameter values, including CAPE, LI, EL, LCL, CCL, RH, lapse rate, tropopause height, and Precipitabe Water. The distribution of volcanic ash was obtained from himawari satellite data on Filezilla which was processed with the Gmsldp Dvorak application. The study was conducted with a period of 15 days before and 15 days after the eruption occurred. The distance between Minangkabau Meteorological Station and Mount Marapi is 49.4 km if a straight line is drawn. The eruption also had an impact on flights at Minangkabau Airport. Analysis of upper air parameters shows that the environmental air lapse-rate value after the eruption tends to be negative. The Equilibrium Index value tends to fluctuate. After the eruption, the CCL height became higher than the LCL height. Vertical RH and precipitable water values tend to decrease on December 3-4, which then fluctuates. LI and CAPE values are moderate in the time period of December 3-5, 2023 which increases the possibility of convective cloud formation. The parameters most affected by Mount Marapi volcanic ash are tropopause height, lapse rate, and LCL.