Nighttime D-region equivalent electron density determined from tweek sferics observed in the South Pacific Region

摘要: Atmospherics or sferics that originate from lightning discharges on propagating large distances in the Earthionosphere waveguide, particularly at night, form dispersed called tweeks. Tweeks are novel diagnostic tool to monitor nighttime D-region ionosphere. Mean equivalent electron density nem mean tweek reflection heights hm and profile have been estimated using higher harmonic tweeks recorded time between 21–03 hrs LT Suva (18.2°S, 178.3°E), Fiji, during a period March–December 2006. The values of vary 29–170 cm−3 altitude range about 3.5 km 83 km. In terms usually used exponential profile, ionospheric reference height sharpness factor calculated be 83.1 0.64 km−1, respectively. scale is 1.9 Equivalent lower ionosphere, method, shows by 20–45% than those obtained IRI-2001 model.