Topband: Moonlight & K-sums

[Ford Peterson]

Earlier I wrote:

> What is interesting about October 17th has to do with what lore refers to as the "harvest moon."  It happens once per year that a full moon appears on the eastern horizon at the exact instance as the sun sets in the west.  I am told there was a partial eclipse of the moon that night too (for what it's worth).  On Monday night, I stood on my porch admiring the moon.  It had an almost halogen color to it.  The light was brilliant white and bright enough to read a newspaper at this rural QTH.  


According to Wikipedia  (http://en.wikipedia.org/wiki/Albedo), the electromagnetic reflectivity of the moon is 12%.  I'm not sure what this has to do with Topband, the high correlation of good topband propagation at this time of year may be just a coincidence.  It may shed some (moon) light on the propagation circuits we use.  

Of course, it may have absolutely nothing to do with ionospheric effects due to reflectivity.  It may have more to do with a moon, complete with a magnetic field, and a sun, also with a magnetic field, interacting with the earth's magnetic field in strange and wonderful ways when the moon is directly on the opposite the sun.  I sat at my desk the other night, pondering my globe.  Tree gives his regular "Boring" reports illustrating spectacular propagation enhancements to EU.  A look at my globe illustrates a direct path between Tree and EU that is almost precisely over the magnetic north pole.  I listen the same nights from my QTH in Minnesota and hear nothing--zippo!  How can this be?  

As others have often commented, it seems impossible for the reflectivity of the moon to induce any sort of enhancement in the ionosphere at night.  I tend to agree.  But what about the magnetic fields?  Could it be that in this "harvest moon" configuration we see an alteration, or even cancellation of the magnetic fields of the three heavenly bodies during the period of peak evening EU propagation?  Something to ponder...

Ford-N0FP
ford at cmgate.com