Very low and low radio frequency (VLF/LF) propagation responds sensitively to the electron densitydistribution in the lower ionosphere (upper mesosphere).Whereas propagation paths crossing subpolar and polar regions are frequently affected byforcing from above by particle precipitations, mid- and lowlatitude paths let forcing from below be moreprominent. Our observations (2009–2011) show, that the low frequency propagation conditions along the midlatitude path from Sicilyto Germany (52° N 8° E) using the NSY 45.9 kHz transmitter (37° N 14° E) prove to be a good proxy of mesosphere planetary wave activityalong the propagation path. High absorption events with VLF/LF propagation correlateto the well known winter time D-layer anomaly observed with high frequency (HF) radio waves.VLF/LF propagation calculations are presented which show that the radio signal amplitude variations can be modeled byplanetary wave modulated collison frequency and electron density profiles.The other way around wave pressure amplitudes can be inferred from the VLF/LF data.
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