Here some interesting paper about LF MF polarization
http://www.ann-geophys.net/22/1705/2004/angeo-22-1705-2004.pdf
This paper, High-latitude propagation studies using a meridional chain of
LF/MF/HF receivers
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Fig. 5. (a) Polarization of 50-5000 kHz signals recorded at
Churchill, Manitoba, on 1-2 October 1997. White pixels indicate
left-hand polarization, black pixels indicate right-hand polarization,
and gray pixels indicate indeterminant polarization. (b)
Power spectral density of the same 50-5000 kHz signals. Received
signals above 1MHz are predominantly left-hand polarized except
in the interval 09:00-12:00UT, 1-4 h before sunrise, when righthand
waves dominate at frequencies above about 3Mhz.
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Figure 5 shows a possibly related effect occuring near
the dawn terminator but involving wave polarization. The
bottom panel shows a spectrogram of 50-5000 kHz signals
recorded at Churchill, Manitoba, for 20 h, starting at
20:00 UT on 1 October 1997, a geomagnetically quiet day
for which the signals show the usual diurnal pattern.
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7'3 N4IS JC
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