Visibility in Southern Utah RE: Sunsets

[Joel Rauber <Joel_Rauber@SDSTATE.EDU>]

> > On rare occasions we can see Rainier (!) from Simon Fraser, a
> > distance of something like 200 miles. (SFU is on a 1200-foot
> > high hill.)
>
> That boggles the mind.  An expert once told me that 100 miles
> is more or less an absolute limit due to atmospheric scattering.
> When I told him that I *regularly* see that far on clear days,
> he softened his position somewhat.  But I'm not sure he would
> believe 200.

I recall seeing a National Park exhibit while on a vacation through
southern
Utah, in 91 or 92, illustrating with photos taken on clear days in the 80's
compared to the 50's and "demonstrating" how much global? pollution effects
had affected visibility in one of the most pollution free areas of the 48
contiguous states.  Apparently much of this global effect was stemming from
the four-corners power plants.  It was quite dramatic, although, less so
compared to such comparative photos I've seen from scenic views in the
Appalachians.

Joel Rauber
Joel_Rauber@sdstate.edu