Topband: lower ionosphere?

[Carl K9LA]

Yuri,

>So, you are trying to imply that atmosphere/ionosphere is only lowered around equator?
>
Since that satellite only measured the equatorial ionosphere, the 
conclusions are only valid for the equatorial ionosphere.

>What magic keeps it unaffected at higher latitudes?
>
There's no magic involved. It's simply an understanding of the different 
physical processes in the atmosphere that occur at low, mid, and high 
latitudes.

>Earth is a sphere, atmosphere/ionosphere is envelope around this sphere and if there are changes in height, those changes would be reflected proportionately in this envelope at the equator and toward the poles, proportionately.
>
Not so. The equatorial ionosphere has a unique process that result in 
ionization at significantly higher altitudes than at mid and high 
latitudes. This unique process is referred to as the fountain effect, 
and it only occurs in the equatorial ionosphere. This is why the 
satellite was launched - to study the high altitude equatorial 
ionosphere in relation to the adverse effects of this ionization on 
equatorial scintillation. 

>NASA found out that during high sunspot cycle atmo/ionosphere expands and that is what slowed down SPACELAB and caused its premature descent.
>
I agree with that, but that is not the issue here. The issue is that the 
equatorial ionosphere at solar minimum is lower than what our current 
models indicate.

Thus all I'm saying is that the mid and high latitude ionosphere is not 
any higher than what our models say. And I'm sure ionosonde data would 
confirm this.

Carl K9LA