Kh. Yearby et Na. Clilverd, DOPPLER-SHIFT PULSATIONS ON WHISTLER-MODE SIGNALS FROM A VLF TRANSMITTER, Journal of atmospheric and terrestrial physics, 58(13), 1996, pp. 1489-1496
Whistler mode signals from the NAA transmitter (24 kHz) received at Fa
raday, Antarctica are processed to obtain the Doppler shift at a much
higher time resolution than has previously been possible. This has all
owed the observation of pulsations of about 13 mHz frequency which are
believed to be associated with hydromagnetic waves in the magnetosphe
re. The pulsations are observed separately on signals with a number of
discrete group delay features that can be interpreted as individual w
histler ducts. Using the measured pulsation phase over the array of du
cts the phase velocity and wave normal direction of the hydromagnetic
wave in the equatorial plane are estimated. The direction of propagati
on is consistent with a source on the dayside magnetopause. The associ
ation between whistler mode Doppler shifts and hydromagnetic waves has
been reported before but not, as far as we are aware, using an experi
mental technique that allows measurements on individual ducts in order
to determine the direction of propagation of the hydromagnetic wave.
(C) 1996 Elsevier Science Ltd