SO2 Dispersion Simulation During Mount Merapi Eruption Using WRF-Chem Model (Case Study on June 21–23, 2020)

SO2 is the most important material released during volcanic eruptions. High concentrations of SO2 can cause various respiratory diseases, visual disturbances, and environmental damage. A good concentration of SO2 in the air is not more than 1.4 ppm for hourly measurements and no more than 120 ppm for daily averages. Meteorological parameters such as temperature and wind affect the distribution of SO2 in the atmosphere. Therefore, this study aims to simulate the distribution of SO2 and the meteorology conditions during the eruption of Mount Merapi using the Weather Research Forecasting-Chemistry (WRF-Chem) model. The used data is SO2 data from the AURA-OMI satellite and meteorological parameter data obtained from the Cilacap Meteorological Station for the period June 21–23, 2020. The output of WRF-Chem shows that high temperatures tend to occur during the day and high wind speeds occur in the morning with the wind direction predominantly blowing to the northwest. Low SO2 concentrations are moving further, and for high SO2 concentrations, the movement is still around the eruption site of Mount Merapi. High SO2 concentrations occur in the morning until late afternoon when the temperature is high, and the wind speed is low. In the research period, the results of the hourly SO2 concentration were dominated by exceeding the good value threshold and the daily average was still in good condition. The result is still underestimated with satellite data. Validation parameter correlation is 0.4.