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E‐region bifurcation and magnetic field related Bragg backscattered spectral events observed at high‐latitude by MF radar
Author(s) -
Morris R. J.,
Holdsworth D. A.,
Murphy D. J.,
Monselesan D. M.
Publication year - 2005
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2005gl024429
Subject(s) - doppler effect , spectral line , spectral slope , backscatter (email) , radar , mesosphere , physics , latitude , range (aeronautics) , geology , polar , computational physics , atmospheric sciences , geodesy , materials science , stratosphere , telecommunications , astronomy , composite material , computer science , wireless
We report on novel spectral characteristics of E‐region backscatter acquired using a 1.94 MHz Medium Frequency (MF) radar above the high‐latitude Antarctic station Davis (68.6°S). Two distinctive Doppler spectra are observed: one that exhibits bifurcation in Doppler velocity (or frequency) with one, or occasionally more, near symmetrical spectral side‐bands (here labelled SSE); and a second that exhibits broad‐band spectra related to the magnetic field topology (here labelled FRE). Both spectral forms reveal a characteristic quasi‐hyperbolic spectral form that diverges in Doppler velocity with range. We discuss the properties of these two spectral forms including: Doppler spectral shape; power spectra; angle‐of‐arrival (AOA) of backscattered sources; and their diurnal and day‐to‐day occurrence distributions for our campaign interval. Interestingly, the E‐region SSE observed at a height near 100 km were observed coincidentally with D‐region polar mesosphere summer echoes (PMSE) in the height range 82–92 km, when colocated data were available.