[M-IS19] Atmospheric electricity

[MIS19-P02] Modeling spatio-temporal dependence of VLF/LF amplitude during solar eclipse occurred in 2012 by 3D FDTD method

*Shogo Kanazawa¹, Yasuhide Hobara^1,2,3, Yoshiaki Ando^1,2,3 (1.The University of Electro-Communications, 2.Earth Environment Research Station, The University of Electro-Communications, Tokyo, Japan, 3.Center for Space Science and Radio Engineering, The University of Electro-Communications, Tokyo, Japan)

Keywords:solar eclipse, VLF/LF transmitter, Finite-Difference Time Domain

In this paper, we investigated the temporal variation of VLF/LF electric amplitude during Solar Eclipse occurred on May 22 in 2012 by using 3-D Finite-Difference Time-Domain (FDTD) method. First, we assumed the altitude dependences of the ion and electron densities as well as the collision frequency between electrons and neutrals for both background and disturbed (during the solar eclipse) lower ionosphere. The ground was assumed to be the perfect conductor. Second, locations of VLF/LF transmitter was placed on the ground in the simulation space. Computed temporal dependences of electric amplitude at several receivers by shifting the disturbed region in time were compared with those from observations by UEC's VLF/LF receiving network. Then we examined the effect of the wave propagation when the center of eclipse is not located over the path between the VLF/LF transmitter and receivers, which has not been studied by 2D approach.