hello to everyone, With respect to Wolf DF2PY's comment about very good propagation on polar routes when the A index and the solar wind speed are elevated, our understanding of what makes 160m tick is lacking. In other words, "stuff happens".
Having said that, there have been similar reports of good propagation on 160m at high latitudes when the K index spikes up. A process that could explain this is tied to changes in the E region and lower F region at elevated K indices. When geomagnetic field activity increases, the atmosphere's electric field (measured in terms of mV/meter) increases. When this happens, the electron density valley above the E region peak can become better developed (deeper and more vertical extent - which would eliminate transits through the absorbing region and eliminate ground reflections). This process comes from a 1984 paper in the Journal of Geophysical Research. It is only a model - I'm not aware of any measurements to confirm that this happens. So "buyer beware". All I can say is - it makes sense. Carl K9LA _________________ Topband Reflector Archives - http://www.contesting.com/_topband