浮遊火山灰拡散モデルの検証に関わる現地計測

Abstract

It is clear that no-fly zone of the airplane during a volcanic eruption has the great influence on the economic activity of the area, based on the 2010 eruptions of Eyjafjallajökull in Iceland. When existence of volcanic ash clouds is estimated as a result of prediction calculation, it becomes impossible to fly the airspace. However, during the volcanic eruption of Iceland, European aviation authorities took the measure which loosens no-fly zone of an airplane according to the concentration of volcanic ash in order to avoid confusion of an air route at an early stage. In that case, the diffusion of volcanic ash clouds grasps viewing or a satellite photograph, and the concentration of volcanic ash is measured by LIDAR (detection by a laser picture) and the dust meter in the light airplane.This research firstly aims at grasping the three-dimensional structure of volcanic ash plume by the in-situ airborne ash measurement.The atmospheric diffusion model which predicts the volcanic ash concentration is verified by the comparison between observed and calculated values. The in-situ field is Mt. Sakurajima in Kagoshima where the eruption frequency is high.By the X band MP radar which the Ministry of Land, Infrastructure, Transport and Tourism installed in Tarumizu City, the distribution and shade of the air-borne volcanic ashes by the eruption of Sakurajima was measured. However, the physical evaluation of the measurement value was considered to be needed, and the possibility of the practical usage of X band MP radar was also investigated.