Plasma blobs and bubbles concurrently observed by ROCSAT-1 and ionosonde in Equatorial Ionization Anomaly region in the Asian-Oceanian sector

Abstract:

With simultaneous ionospheric measurements from ROCSAT-1 Satellite and ground ionosondes, three cases of concurrent plasma blobs and bubbles in the same magnetic meridian were observed around 22:30 LT in Asian-Oceanian sector near solar maximum. Two cases observed Equatorial Spread F (ESF) over Vanimo station (geog. 2.7°S, 141.3°E; geom. 11.2°S, 146.2°W) and plasma blobs around 8.0°S (geom.) on June 1 and October 6, 2003. The other case observed ESF over Hainan station (geog. 19.5°N, 109.1°E; geom. 9.1°N, 179.1°W) and plasma blob near the dip equator on March 8, 2004. Plasma blobs were all observed near 600 km height, above the ESFs. Scintillations were also observed near the same magnetic meridian. Considering that both plasma bubbles and blobs are field-aligned elongated structures, these concurrent detections of plasma blobs and bubbles provide direct observational evidence for the proposed blob formation in the intermediate stage of plasma bubble generation proposed by Huang et al., (2014).