This is an image of the sunrise from space over the South China
Sea. An astronaut would see something like this; clearly
defined bands of color through the atmosphere as the sun rises.
High-peaking cumulus clouds, topping out in anvil-head cirrus
can be seen as black shadows against the sunlit horizon. The
brightness of the colors in the atmosphere in this photograph is
due to the amount of dust in the atmosphere. More dust is found in
near the equator. There are various sources for such upper
level dust. Many dust storms in Africa and ash clouds from major
volcanic eruptions are two reasons.