I do agree that a cloud layer is probably the better way to go. Keep in mind that most of the current cloud presets - the "Easy clouds" - will not allow you to have a blank density function. Best to use a v2 cloud layer (currently available as a "Global cloud layer" preset), as others mentioned.
v3 clouds have the same control over altitude, thickness, etc.
They are, however, restricted to being "localized", although the area can be quite large. *Easy clouds* are more limited, but they are not the only available example of v3 clouds.
- Oshyan