Nighttime D region electron density measurements from ELFVLF tweek radio atmospherics recorded at low latitudes

Ajeet, K.M. and Veenadhari, B. and Singh, R. and Kumar, Sushil and Cohen, M.B. and Selvakumaran, R. and Sneha, G. and Pant, P. and Singh, A.K. and Inan, U.S. (2012) Nighttime D region electron density measurements from ELFVLF tweek radio atmospherics recorded at low latitudes. Journal of Geophysical Research (Space Physics), 117 (A1130). pp. 1-13. ISSN 0148-0227

PDF - Published Version Restricted to Registered users only Download (1MB)

Abstract

Dispersive atmospherics (tweeks) observed during 2010 simultaneously at two low-latitude stations, Allahabad (geomagnetic latitude, 16.05�N) and Nainital (geomagnetic latitude, 20.48�N), have been used to estimate the nighttime D region electron density at the ionospheric reflection height under the local nighttime propagation (21:00–02:00 LT or 15:30–20:30 UT). The analysis of simultaneously recorded tweeks at both the stations on five international quiet days during one month each from summer (June), winter (January), and equinox (March) seasons shows that the D region electron density varies 21.5–24.5 cm�3 over the ionospheric reflection height of 85–95 km. The average values of Wait lower ionospheric parameters: ionospheric reference height h′ and sharpness factor b are almost same during winter (85.9–86.1 km, 0.51–0.52 km�1) and equinox (85.6–85.7 km, 0.54 km�1) seasons. The values of h′ and b during summer season are about 83.5 km and 0.60 km�1 at both stations. Overall, equivalent electron density profile obtained using tweek method shows lower values of electron density by about 5–60% than those obtained using the International Reference Ionosphere (IRI-2007) model and lower/higher by 2–68% than those obtained using rocket technique. The electron density estimated using all three techniques (tweek, IRI-2007, and rocket) is consistent in the altitude range of 82–98 km. The estimated geographic locations of causative lightnings of tweeks were matched with the locations and times of lightnings detected by the World-Wide Lightning Location Network (WWLLN). The WWLLN detected about 27.5% of causative lightnings of tweeks simultaneously observed at both the stations.

Item Type:	Journal Article
Subjects:	Q Science > QC Physics
Divisions:	Faculty of Science, Technology and Environment (FSTE) > School of Engineering and Physics
Depositing User:	Sushil Kumar
Date Deposited:	28 Nov 2012 02:06
Last Modified:	11 Jul 2016 03:17
URI:	https://repository.usp.ac.fj/id/eprint/5312

Actions (login required)

View Item