Japan Geoscience Union Meeting 2019

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[J] Oral

P (Space and Planetary Sciences ) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

[P-EM16] Physics and Chemistry in the Atmosphere and Ionosphere

Wed. May 29, 2019 9:00 AM - 10:30 AM A03 (TOKYO BAY MAKUHARI HALL)

convener:Yuichi Otsuka(Institute for Space-Earth Environmental Research, Nagoya University), Takuya Tsugawa(National Institute of Information and Communications Technology), Seiji Kawamura(National Institute of Information and Communications Technology), Chairperson:Mitsumu Ejiri(国立極地研究所), Yuichi Otsuka

9:00 AM - 9:15 AM

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

*Chia-Hung Chen1, Charles Lin1, Tomoko Matsuo2 (1.Department of Earth Sciences, National Cheng Kung University, 2.Department of Aerospace Engineering Sciences, University of Colorado at Boulder, CO)

Keywords:Ionospheric data assimilation, solar eclipse, electric field perturbation

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.