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

[PEM12-P16] DC electric field analysis during the nighttime medium-scale traveling ionospheric disturbance observed by S-520-32 sounding rocket

*松山 実由規¹、石坂 圭吾¹、芦原 佑樹²、山本 衛³、熊本 篤志⁴、白澤 秀剛⁵、阿部 琢美⁶ (1.富山県立大学、2.奈良工業高等専門学校、3.京都大学/RISH、4.東北大学、5.東海大学、6.JAXA/ISAS)

キーワード：中規模伝搬性電離圏擾乱、観測ロケット、電場

The Medium Scale Traveling Ionospheric Disturbance (MSTID) is a plasma density structure in the mid-latitude ionospheric F region, especially, the nighttime MSTID occur in summer. The growth principle of the nighttime MSTID is proposed the Perkins instability and electromagnetic coupling of the ionospheric E-F region. The S-520-32 sounding rocket was launched from JAXA Uchinoura Space Center at 23:20 JST on August 11, 2022 to investigate the nighttime MSTID generation mechanism. The Total Electron Content maps (TEC) observed by the GNSS satellite showed northwest-southeast structures at the time of launch.
The Electric Field Detector (EFD) on board of this rocket observed low frequency electric fields from DC to 50 Hz in situ. It has two orthogonal dipole antennas with a tip-to-tip 5.5 m and observed electric fields of two orthogonal components in the spin plane perpendicular to the rocket axis using the double probe method. The observed data showed a sinusoidal waveform of 0.95 Hz, the same as the spin frequency. This indicates that the EFD successfully observed the composite of the natural electric field and the induced electric field from the rocket motion across the magnetic field.
In this paper, we will show the analysis result of the DC electric field observed by the S-520-32 sounding rocket and reveal the relationship between the DC electric field and the plasma density structure.