Presentation on theme: "Seismology Forum Meeting 2014："— Presentation transcript:
1 Seismology Forum Meeting 2014： Recent Advances and New Findings in SeismologyAn Electric Coupling Model for the Lithosphere-Atmosphere-Ionosphere SystemL. C. LeeInstitute of Earth Sciences, Academia SinicaMarch 19, 2014
2 Ionosphere density variations Lithosphere – atmosphere – ionosphere couplingKuo, Huba, Joyce and Lee, JGR (2011, 2013)Ionosphere density variationsVariations of fmF2 and TEC before Chi-Chi EQEQ[Liu et al., 2001]
6 Model of DC electric field generation in the ionosphere by seismic related EMF (electro-motive force) in the lower atmosphere. 1. Earth surface, 2. Conductive layer of the ionosphere, 3. External electric current of EMF in the surface atmosphere, 4. Conductivity electric current in the atmosphere–ionosphere circuit, 5. DC electric field in the ionosphere, 6. Field-aligned electric current, and 7. Charged aerosols injected into the atmosphere by soil gases (Sorokin and Hayakawa, 2013).
7 Thunderstorm effect on the ionosphere 𝛟 ≃ 250kVFair weathercurrentJ1J2JD𝛟=𝟎
19 NRL 3D ionosphere simulation code (SAMI3) SAMI3 is a 3D low-latitude ionospheric model developed at the Naval Research LabSAMI3 simulates the temporal and spatial evolution of seven ion species (H+,He+,N+,O+,N2+,NO2+,O2+) over the entire magnetic flux tube in both hemispheresThe density and velocity equations are solved for all ion species.Ion temperature equation and electron temperature equationsThe altitude range is ±30° and the longitude range is 8° for our caseThe range of magnetic apex height is 85 to 2400 km
20 Modified potential equation in SAMI3 (1)(2) Use Dipolar Coordinates(dipole magnetic field lines)
27 SummaryThe magnitude of current density Jrock is the most important parameter to determine the TEC variations and nighttime bubble formation in the ionosphere.The current density Jrock = nA/m2 in the earthquake fault zone can cause TEC variations of up to 2 – 20 % in daytime ionosphere.A current density Jrock = nA/m2 can lead to nighttime TEC variations of % as well as the formation of nighttime plasma bubble (equatorial spread F) extending over the whole magnetic flux tube containing the earthquake epicenter.Daytime and nighttime TEC variations and nighttime plasma bubbles within the affected region can be used as precursors for earthquake prediction.
28 Institute of Earth Sciences, Academia Sinica Thank You中央研究院 地球科學所Institute of Earth Sciences, Academia SinicaTaipei, Taiwan