Japan Geoscience Union Meeting 2023

Presentation information

Print

[E] Oral

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

[P-EM12] Coupling Processes in the Atmosphere-Ionosphere System

Sun. May 21, 2023 9:00 AM - 10:15 AM 101 (International Conference Hall, Makuhari Messe)

convener:Huixin Liu(Earth and Planetary Science Division, Kyushu University SERC, Kyushu University), Yuichi Otsuka(Institute for Space-Earth Environmental Research, Nagoya University), Loren Chang(Department of Space Science and Engineering, National Central University), Yue Deng(University of Texas at Arlington), Chairperson:Katelynn Greer(Laboratory for Atmospheric and Space Physics), Yuichi Otsuka(Institute for Space-Earth Environmental Research, Nagoya University)


10:00 AM - 10:15 AM

[PEM12-05] Observations of Ionospheric Disturbances driven by eruption of Hunga-Tonga-Hunga-Ha'apai volcano using FORMOSAT-7/COSMIC-2

*Charles Lin1, P. K. Rajesh1, Chi-Yen Lin2, Jia-Ting Lin1, Jong-Min Choi1, Cheng-Yung Huang3 (1.Department of Earth Sciences, National Cheng Kung Univ., 2.Center for Astronautical Physics and Engineering, National Central Univ., 3.Taiwan Space Agency)

Keywords:FORMOSAT-7/COSMIC-2 , global ionospheric specification, traveling ionospheric disturbances

The global low-latitude ionosphere observations given by the Tri-GNSS radio occultation system (TGRS) and ion velocity meter (IVM) onboard the FORMOSAT-7/COSMIC-2 (F7/C2) have been applied to study the ionosheric responses to the moderate geomagnetic storms. Results show that the ionosphere responses are much greater than expectation as the moderate storms could double or triple the electron density, which was only possible during major magnetic storms under higher solar activity conditions. On January 15th 2022, the Tonga volcano eruption unleashed a strong global atmosphere perturbations and coincided with a moderate geomagnetic storm. The ensuing thermospheric variations created a rare display of extreme poleward-expanding conjugate plasma bubbles in rate of total electron content indices over 100-150°E, also causing ion-density fluctuations in IVM measurements reaching ~40°N geographic latitude. This was preceded by an unusually strong pre-reversal enhancement (PRE) of low latitude ionosphere as seen from the global ionospheric specification (GIS) which is constructed based on the TGRS observations. The GIS further revealed sharp decrease of equatorial ionization anomaly (EIA) crest density due to the storm impact. The enhanced F-region wind over EIA by the negative storm, when combined with volcano induced E-region westward disturbance wind, apparently intensified the PRE. In presence of the strong PRE, seed perturbations from volcano induced variations triggered the super plasma bubble activity.