What a great photo .
I saw something interesting on the way home yesterday.
The sun had gone down below the horizon of the mountain ridge to the west of me. Even though I could no longer see the sun the bottom of the patchy clouds above me were lite up. My elevation at that point is 125 feet. I could also see the shadow line of the mountain ridge to the wast cast onto the mountains to the east which are 3,000 feet higher in elevation than the ones to the west are. I ascend up into the mountains to the east to get home. You ascend quit rapidly from 125 feet in elevation to 3,500 in elevation.
I acceded above the shadow line where I could see a portion of the sun above the horizon and still see the bottom of the clouds lite up. Quite beautiful.
Now, I'm going to describe a phenomena I witness quite often in these mountains.
A lot of times there will be two or more layers of clouds at different elevations due to air temps and types of clouds.
One layer will be dens and cold air has it at a very low elevation far below the peaks on the mountains while the other clouds will be much higher than the mountains.
As the sun sets, I'm descending the mountain from above the lower layer of clouds and can see the sun as it shins on both the TOP of the lower layer and BOTTOM of the top layer. Quite a beautiful sight I must say.
I watch the sun sink below the lower layer and can no longer see the sun but still see the bottom of the top layer still lit up.
As I descend below the bottom layer once again the sun becomes viable and I see both layers of clouds lite up on their bottoms.
Eventually the sun drops below the horizon and of course for a short period of time the bottoms of both layers of clouds are still lite up.
Here's a part of this phenomena that shows curvature along with sun set rather the sun just moving off in the distance.
You can see the bottoms of the clouds lite up at a greater distance towards the horizon long after the ones closer to you go dark.
That is pretty good evidence the sun sets over a curvature rather than it just getting farther and farther away while remaining at 3,000 feet above the earth.
By the way I saw your signature before you changed it
Also clouds can be 6,000 feet, about 1 mile above the ground or lower from the ground trapped in temperature layers such as I witness in my area. A far reach from 3,000 miles.