[P-EM20] Recent Advances in Ionosphere Observation and Modeling through New Observation Opportunities

[PEM20-P03] Ionospheric responses on the 21 August 2017 solar eclipse by using three-dimensional GNSS tomography

*陳 佳宏¹、Lin Charles¹、齊藤 昭則²、山本 衛³、斎藤 享⁴ (1.台湾国立成功大学地球科学学科、2.京都大学大学院理学研究科地球物理学教室、3.京都大学生存圏研究所、4.国立研究開発法人海上・港湾・航空技術研究所　電子航法研究所)

キーワード：電離圏GNSSトモグラフィー、2017年8月日食

In this study, we study the ionospheric responses on the August 2017 solar eclipse event by using a three-dimensional tomography algorithm with the ground-based GNSS (global navigation satellite system) total electron content observations around the Northern America. This three-dimensional ionospheric electron density structure from the tomography can provide us more information regarding to how the density variations and propagations are. Results show that the ionospheric electron density depletion triggered by the solar eclipse is distributed to all the altitudes. The most electron density depletion is around 40% compared with the previous day of solar eclipse. We further conduct a procedure of Fourier analyses to derive the vertical phase and group velocities of the electron density propagations. Results show that the opposite directions of the vertical phase and group velocities around 300 km altitude imply the energy source by the solar eclipse.