smoke upside down: underwater effect?

Hi,

[
Edit: or maybe let the smoke as is and use the keys on the timeline to move the smoke… I will try, sorry about this question]
I would like to create a smoke underwater, such as when you dive in a swimming pool, there is a sort of smoke that goes down (with your body) and then stay still for a moment.
Would you know how I could make the smoke goes “down” and not “up”? I tried to rotate the plane inside the cube by 180°, or set the gravity to a negative value, but it did not work! Any idea?
]

two values that determine which direction smoke travels are the domain behaviour controls for “density” and “temp difference”. easiest solution is to leave density at default value and change temp difference to a negative.