Topband: 160 Meter Propagation

[Larry Molitor]

At 06:32 PM 1/6/01 -0800, k6se@juno.com wrote:

>1) Toward JA is mostly over sea water and to EU is mostly over land.
>2) Toward JA totally avoids the auroral zone and to EU the path goes
>through it.

Earl and others,

I'm still having trouble with this.

 From me to JA is about 20% over land. To EU is about over 55% or 60% land. 
Given the propagation stations in other geographical areas have across 
similar land masses, I cannot believe this would account for more than a 
small fraction of the differences I see. Look at the JA to EU path. 95% 
land, and almost 9000 km. Judging by the DX summit spots, it's not a real 
tough path. I just don't see the evidence that backs up the land mass theory.

The auroral data I use is at:

http://sec.noaa.gov/pmap/pmapN.html

Tonights plot suggests that the path from me to EA is no worse than the 
path from me to JA. Both great circle paths just graze the lowest energy 
level plotted. The path to northern EU is through a high energy area of the 
auroral oval and it's no surprise to me tonight that I can't hear any of 
the posted north and central EU activity. On quiet nights, the oval is 
small enough that my path to EU does not even graze it. These are the times 
that I expect but never see propagation.

The only explanation that I can come up with is that the satellite 
generated charts are not an accurate representation of the area 
dramatically affected by absorption. If the absorption area extends much 
further south than the plots indicate, my path would almost never be out of 
it. I expect that must be the case, but can find no data to back that up. 
Is there a better indicator I could use?

Discussion?

73,

Larry - W7IUV


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