HFドップラーにより観測された地震に伴う電離圏変動の中性大気波動数値シミュレーションによる定量的評価

抄録

In order to evaluate the relationship between the coseismic ionospheric perturbations and the ground perturbations, we compare the coseismic disturbances determined by a numerical simulation with those observed by HF Doppler. HF Doppler observation determines the ionospheric vertical drift speed of the reflection point. The numerical simulation calculates the temporal evolution of the neutral acoustic wave, In this numerical simulation, the ground perturbations observed by seismometers closest to the reflection points are used as sources of the perturbations. The speed estimated from HF Doppler is about an order larger than that calculated from numerical simulation. The difference is because the speed of the ionospheric vertical drift is not same as the neutral atmospheric wave. In order to fix this difference, the ionospheric neutral drift speed is modified considering the effects of the inclination of the magnetic field and the compression of ionospheric plasma. As a result, the both speed are comparable each other.