Observations of traveling ionospheric disturbances and 3-m scale irregularities in the nighttime F-region ionosphere with the MU radar and a GPS network

摘要: The nighttime traveling ionospheric disturbances (TIDs) and the F -region 3-m scale field-aligned irregularities were simultaneously observed with MU radar GEONET, a GPS network, during FRONT (F-region Radio Optical measurement of Nighttime TID) campaign periods in May 1998 August 1999. vertical profile electron density detected by incoherent scatter observation clarified that ionized atmosphere on bottomside F-region was deeply modulated TIDs, which would cause variations 630 nm band airglow luminosity. coherent echoes from also nights when TIDs intense amplitude ionosphere uplifted. Two-dimensional structures multi-beam revealed formed band-like traveled to southwest several nights. Their wave vector velocity coincident those TEC GEONET. Doppler velocities indicate polarization electric field is generated inside TIDs. We consider horizontal gradient conductivity associated generates through gradient-drift instability process. anti-correlation occurrence rate solar activity be caused Pedersen conductivity.