[P-EM12] Study of coupling processes in solar-terrestrial system

[PEM12-03] Sounding of E-F coupling over Japan by using ground-based GNSS TEC with a double-thin-shell approach

*Weizheng Fu¹, Tatsuhiro Yokoyama¹, Nicholas Ssessanga², Mamoru Yamamoto¹ (1.Research Institute for Sustainable Humanosphere, Kyoto University, 2.4DSpace, Department of Physics, University of Oslo)

Keywords:Ionosphere, GNSS, TEC, Double-thin-shell model

Irregularities in the ionospheric E and F regions are frequently coupled in the nighttime mid-latitude ionosphere, observationally and theoretically. In this paper, total electron content (TEC) measurements from a dense ground-based Global Navigation Satellite System (GNSS) array with more than 1200 receivers are used to investigate the E-F coupling phenomenon over Japan by taking a double-thin-shell approach. We assumed that the TEC perturbations (TECPs) mainly concentrate in E and F regions; two thin shells parameterize the three-dimensional (3-D) ionosphere; perturbation components are identical at any point within a given grid block of each layer. Validation shows that the irregularities in E and F regions can be reconstructed simultaneously by this newly-developed technique. In this paper, we investigated two event days of nighttime medium-scale traveling ionospheric disturbances (MSTIDs). The coexistence of northwest-southeast (NW-SE) aligned irregular structures in both E and F regions was observed with ground-based GNSS TEC for the first time. The reconstruction results show that the E- and F-region irregularities share similar propagation parameters, which are clear evidence that they are strongly coupled with each other.