• Journal of the Korean earth science society
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• v.35 no.4
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• pp.237-248
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• 2014

To analyze the characteristics of deposition and dispersion of volcanic ash emitted from Mt. Kirishima on January 26, 2011, several numerical simulations were carried out by using the numerical models including Weather and Research Forecast (WRF) and FLEXPART. The dispersion of ash located under 1 km high tends to be concentrated along the prevailing wind direction on January 26 2011. On the other hand, volcanic ash released on the following day spreads to Kirishima bay due to the intensified high pressure air mass in southern Kyushu. When Siberian air mass was intensified January 26, 2011, the deposition of volcanic ash is concentrated restrictedly in the narrow area along the wind direction of the downwind side of Mt. Kirishima. The development of high pressure air mass over the eruption area tends to induce the intensified horizontal diffusion of volcanic ash. Since the estimated deposition of volcanic ash is agreed well with observed values, the proposed numerical simulation is reasonable to use the assessment on the behavior of volcanic ash.