Plasma structures of 3-meter type 1 and type 2 irregularities in nighttime midlatitude sporadic E region

摘要: [1] Although the plausible mechanisms involved in generation of midlatitude type 1 sporadic E (Es) irregularities have been suggested, rare observational evidence is provided to validate proposed plasma structure associated with Es irregularities. In this article, echoes observed by Chung-Li VHF radar located equatorial anomalous region are interferometrically analyzed and corresponding reconstructed. We find that has sharp lateral top bottom boundaries thickness about 1–2 km horizontal extent 3–5 E-W direction. Its dimension N-S direction cannot be resolved using interferometry technique because considerably narrow width expected echoing elevation. The Doppler velocity can as low 220 m/s, substantially smaller than nominal ion acoustic wave speed (about 360 m/s) region. spatial concurrent 2 also result strongly suggests it a well-defined thin layer 9–17 direction, very different from whole moves bodily toward east at 31 no vertical displacement observed. Although movement indistinct, descends remarkably rate 10.3 m/s. These features imply for present case factors governing dynamic behavior independent, irrespective fact clump separates only 4 distance.