FIRST OBSERVATIONS OF TYPE-1 SPORADIC-E IRREGULARITIES IN THE EQUATORIAL ANOMALY REGION USING THE CHUNG-LI VHF RADAR

In this paper we present the characteristics of mid-latitude irregular ities first observed with the 52 MHz Chung-Li radar. Intense type-1 ec hoes with Doppler velocities of about 270 m/s (slightly smaller than t he nominal ion-acoustic wave speed of 360 m/s) in the height range fro m 103.1 km to 104.5 Irm lasted for about 2 minutes. The range-time var iations of sequential power spectra indicate that the patch of type-1 irregularities moved toward the radar at a rate of about 42 m/s. The z onal drift motions of the type-1 and type-2 irregularities obtained fr om an interferometry technique showed that the irregularities drifted eastward with ail average speed of 84 m/s.