Open AccessHF echoes from ionization potentially produced by high‐altitude discharges
Author(s) -
RousselDupré R. A.,
Blanc E.
Publication year - 1997
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/96ja02354
Subject(s) - altitude (triangle) , ionization , thunderstorm , ionosphere , lightning (connector) , atmospheric sciences , physics , geology , meteorology , geophysics , ion , geometry , mathematics , power (physics) , quantum mechanics
The presence of ionization associated with high‐altitude discharges has been detected using an HF radar operating at 2.2, 2.5, and 2.8 MHz. On several occasions, oblique echoes lasting several hundred ms at night and 1 → 10s during the day were observed. The echoes turned on in several interpulse times of 70 ms and were generally correlated with strong lightning activity prior to onset. The angles of arrival of sferics detected at three goniometer stations were used to determine the distance to thunderstorms. The data are consistent with specular reflections from columns of ionization produced at 55–65 km altitude and having minimum electron densities of 6 × 10 4 – 10 5 cm −3 . The source of the ionization is believed to be high‐altitude discharges.