Why is the top of a canyon visible from the bottom during a rainy hike, but once at the top, the bottom is invisible because of the fog?

Question

During a rainy hike canyon walls are visible from the bottom (although a bit foggy). However, when I got to the top, I couldn’t see the bottom anymore—everything was just white. Can someone explain like I’m five why the top is visible from the bottom, but not the other way around?

Edit: missing detail, the weather didn’t change throughout the hike. An the Bailong Elevator led to the top so we reached it within a minute or so. When going down by a cable car the canyons became visible again.

In: Physics

Answer 1

When you’re at the bottom of the canyon looking up, you can see the top because the fog is usually denser at the bottom and lighter as you go higher, allowing you to see through the lighter fog to the top. When you’re at the top looking down, the fog is thicker below you, blocking your view of the bottom and making everything look white.