Conjugate observations of the mid-latitude electric field fluctuations with the MU radar and the Freja satellite

摘要: Abstract Conjugate Freja satellite and MU radar observations were conducted from 1993 to 1995 clarify the generation mechanism of mid-latitude electric field fluctuations (MEFs) which found DE-2 observations. The detection MEFs at higher altitudes than 1000 km by confirms that are transmitted along geomagnetic line without any significant damping. On one night such conjugate observations, observed in a traveling ionospheric disturbance (TID). other nights when Freja, large scale density structures ionosphere with radar. Spread-F phenomena also ionosondes associated these structures. modulation ionosphere, as TIDs, might cause small modulations grow through instabilities. linear growth rate is evaluated using set equations describing irregularities. shown be too under average conditions; however, neutral wind TIDs included, it enough generate MEFs.