[P-EM09] Study of coupling processes in solar-terrestrial system

[PEM09-P05] RELATIONSHIP OF F LAYER HEIGHT RISE, ESF ONSET TIME, AND AMPLITUDE OF LARGE SCALE WAVE STRUCTURE

*Dyah Rahayu Martiningrum¹, Mamoru Yamamoto², Tatsuhiro Yokoyama³, Prayitno Abadi⁴, Pornchai Supnithi⁵, Minh Le Huy⁶ (1.Graduate School of Informatics, Kyoto University, 2.Research Institute for Sustainable Humanosphere, Kyoto University, 3.National Institute of Informatics and Communications Technology (NICT), Tokyo, 4.Solar-Terrestrial Environment Laboratory (STEL), Nagoya University, 5.Faculty of Engineering King Mongkut's Institute of Technology, Ladkrabang, Thailand, 6.Institute of Geophysics Vietnamese Academy of Science and Technology, Vietnam)

Keywords:F layer height rise, Large Scale Wave Structure, onset time of Equatorial Spread F

Under favourable conditions ionospheric plasma at the bottomside of the F-region can become unstable. Plasma irregularities in several scales produced by Rayleigh-Taylor Instability mechanism. The recombination process at the E-region after sunset causing the bottom side F-region electron density gradient become steep. At the same time the eastward electric field intensified just before it reverses to the westward electric field causing the peak of the F region rise known as evening prereversal enhancement. The relationship between onset time of field aligned irregularities related to ESF observed by Equatorial Atmosphere Radar during 2010-2012 with F layer height rise observed by ionosondes near geomagnetic equator, Chumphon (10.7 N; 99.4 E; 0.86 N) and Bac Lieu (9.3 N; 105.7 E; 0.62 N) is discussed in correspondence with growth rate of Rayleigh Taylor instability development. The field aligned irregularities onset time associated with equatorial spread F observed into two different cases, first case where the EPB/ESF onset time concurrent with the peak of virtual height of F region - (h’F) time. Second case where the EPB/ESF onset time happened with delay of more than 30 minutes, with reference to the peak of virtual height of F region - (h’F) time. The possibility that the amplitude of Large Scale Wave Structure obtained from GRBR data effects the height of plasma instability development also discussed.