Study of the ionosphere responses to lithospheric activities using GNSS and FORMOSAT-7/COSMIC-2

FORMOSAT7-COSMIC2 Mission is consist of six satellites equipped with GNSS radio occultation (RO) payload, in-situ ion density and velocity meters (IVM), and RF beacon transmitters at low latitudes. Signal-to-noise ratio (SNR) of RO soundings provides observations of irregularity altitudes, and IVM measures in-situ density fluctuations at satellite altitude of 550 km. Combining RO, IVM, ground-based receivers of beacon and GNSS, it is like an observation suite of plasma irregularities that provides unprecedented number of observations that were not available previously. The observation suite provides opportunity to monitor the variations of plasma irregularity structure and possibly be able to see their growth and subsidence. As the solar activity elevated to date, our observations show that seasonal irregularities occur more frequently with grater intensity. Meanwhile, as the magnetic storms also occur much more often with greater intensity, storm time variations of the irregularities become much more complex. In this presentation, we show that growth of strong low latitude plasma irregularities during storms and some of them last over the entire evening period. They are likely driven by the interplay of electric field and traveling ionospheric disturbances driven by magnetic storms. We will also present the dynamic irregularities driven by nature hazard events, such as earthquakes, tsunami and volcanos, from the observation suite which shows that the extreme event could lead to irregularity growth comparable to those driven by the space weather events. The recent results driven by 2022 Tonga volcano eruption is shown as the example.