Smoke sim- rise with different gravity params?

I’ve got some smoke working properly, but I want it to rise along the y-axis instead of the z-axis.

Trouble is, the scene gravity settings do not seem to have any effect on the direction of the smoke at all. Gravity is fully enabled in the smoke field weights.

Is this a bug, is there a work-around to this, or am I forgetting some crucial box that needs to be checked?

You enabled Newtonian physics?

For the particle emitter, yes, but no such option is available for the smoke sim itself.