Fog on a spherical world

I am trying to achieve a fog effect on custom spherical terrain with a spherical physical based sky. My camera rotates so it is always follows the terrain's curvature (camera is up-side-down at the south pole). What's the best way to go about implementing fog in this setting?

I've tried adding fog through the volume component but that fog seems to be fixed along the y-axis with no way of rotating it. Ideally I'd like to have a fog that is height based that also has it's up vector follow the spherical terrain.. however, having a "standard" fog that is only depth based is also adequate but I haven't found any docs on that using hdrp.