On the appearance of sporadic-E and the occurrence of daytime GHz scintillation

Scintillations on gigahertz (GHz) radio signal are observed during daytime due to electron density irregularities in the equatorial E-region. The occurrence of these irregularities in presence of sporadic E (E_s) can result in GHz scintillations during daytime. This study focuses on the investigation of E_s in the equatorial region using Global Navigation Satellite System (GNSS) signal transmissions received on the ground and in space. We bring two datasets to bear; (1) GNSS based radio occultation (RO) technique, which provides an ideal limb-viewing geometry from space for studying the feature of E_s, and (2) GPS ground-based station. These two datasets provide a unique opportunity to study the feature and structure of E_s. The occurrence of daytime GHz Scintillation (DGS) present from GPS scintillation/TEC data recorded by the GSV4004 receiver at Universiti Kebangsaan Malaysia (UKM) (2.55°N, 101.46°E; dip latitude (Φ) = 5.78°S) station in Malaysia. The results obtained from these two datasets show that (1) E_s structures existed over the UKM station as denoted by the RO observations, and (2) the appearance of E_s is associated with the occurrence of DGS.