[NLRS] Tropo Maps

[Dr.Gerald Johnson]

As far as I can remember, MF propagation hasn't been linked to weather 
conditions just to solar induced ionizations. I'm sure AM broadcast research 
goes back to 1922. For sure thunderstorms adversely affect received signal 
to noise ratios though.

At VHF and up many weather conditions are known to affect propagation 
and some modes like Sporadic E and Aurora E haven't been explained yet. 
There seems to sometimes be correlation between storm tops and Sporadic 
E cloud initiators but sometimes not. Probably what we observe as Sporadic 
E events have several different causes, sometimes mutually exclusive, 
sometimes working together. Wind shear at altitude is a possible source of E 
clouds.

I think that weather phenomena below 50,000 feet may be too restrictive, 
but the balloons don't have any idea about electric charge and charge 
from solar insolation or other events is what makes propagation reflectors 
whether at 1.8 or 50+ MHz.

Give it a shot, huge hard drives aren't very expensive these days, look at all 
the available sounding data, I think you will find that the data BELOW 50K 
feet will be the least interesting for all but temperature inversion events, 
warm air overruns at fronts, and high pressure domes.

73, Jerry, K0CQ


         
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