*Jann-Yenq LIU1,2,3, Yuh-Ing Chen4, Yun-Cheng WEN2, Chi-Kuang Chao1,2,3
(1.Center for Astronautical Physics and Engineering, National Central University, Taiwan, 2.Department of Space Science and Engineering, National Central University, Taiwan, 3.Center for Space and Remote Sensing Research, National Central University, Taiwan, 4.Graduate Institute of Statistics, National Central University, Taiwan)
Keywords:Advanced Ionospheric Probe, FORMOSAT-5, seismo-ionospheric precursor, global ionosphere map, total electron content, z test
The mission of Advanced Ionospheric Probe (AIP) onboard FORMOSAT-5 (F5) satellite is to detect seismo-ionospheric precursors (SIPs) and observe ionospheric space weather. F5/AIP plasma quantities in the nighttime of 22:30 LT (local time) and the total electron content (TEC) of the global ionosphere map (GIM) are used to study SIPs of an M7.3 earthquake in the Iran-Iraq Border area on 12 November 2017, as well as signatures of two magnetic storms on 7 and 21-22 November 2017. Statistical analyses of the median base and z test are employed to find the characteristics of temporal SIPs in GIM TEC over the Iran-Iraq area. The anomalous increases of the GIM TEC and F5/AIP ion density over the epicenter area on 3-4 November (day 9-8 before the M7.3 earthquake) agrees with the temporal SIP characteristics that the significant TEC increase frequently appears on day 14-6 before 53 M5.5 and greater earthquakes in the area during 1999-2016. The spatial analyses show that the SIPs frequently appear specifically over the epicenter day 9-8 before the M7.3 earthquake and day 10-9 before a M6.1 earthquake on 1 December, while proponent TEC increases occur at worldwide high-latitudes on the two magnetic storm days. The F5/AIP ion velocity uncovers that the SIPs of the two earthquakes are caused by eastward seismo-generated electric fields, and the two positive storm signatures are due to the prompt penetration electric fields.