[P-EM09] Dynamics in magnetosphere and ionosphere

[PEM09-P04] Numerical simulation on electrodynamics of the pre-earthquake ionospheric anomalies

*Chuan-ping LIAN¹、Charles LIN¹ (1.Institute of Earth Sciences, College of Sciences, National Cheng Kung University)

キーワード：earthquake precursor, ionospheric dynamics, total electron content

Over the last few decades, ionospheric observations indicate that the total electron content (TEC) often significantly decreases in afternoon on 3-5 days before the M>6.0 earthquakes. It is generally considered that electric currents driven by stressed rock flow into ionosphere. We use NRL 3D ionosphere model, SAMI3 to simulate this phenomenon, and add external current terms into current continuity equation. The range of external current distribution is 120±20oE, 30±20oN, 85~170km, and the maximum current density is 500nA/m2. Our simulation result indicates that the upward current on the bottom of ionosphere produces the maximum (minimum) variation of increasing (decreasing) ~30% (~10%) ∆TEC. The increasing ∆TEC is mainly located in west region of external current; however, the decreasing ∆TEC is mainly located on both sides of increasing region.