[P-EM16] 大気圏・電離圏

[PEM16-01] The model study of ionospheric variations during the solar eclipse event by assimulating the GNSS TEC observations

*陳 佳宏¹、Lin Charles¹、Matsuo Tomoko² (1.台湾国立成功大学地球科学学科、2.コロラド大学航空宇宙工学)

キーワード：電離圏データ同化、日食、電場変動

Using the physics-based thermosphere-ionosphere model (NCAR-TIEGCM) with an ensemble Kalman filter, this study reports the first data assimilative analysis of the ionosphere responses to the solar eclipse on 21 August 2017. The system, using a 2-minute assimilation cycle of data from ground-based GNSS observations, show dynamic variations of the equatorial ionization anomaly (EIA) due to the electrodynamic effects of the solar eclipse. Two major ionospheric responses are captured: (1) an early appearance of EIA at the westward boundary of moon shadow and (2) an enhanced EIA at lower latitudes and suppressed EIA at the higher latitudes. These eclipse-induced conjugate EIA variations are produced by an eastward electric field perturbation around magnetic equator and a westward electric field perturbation at the higher latitudes.