How does Lucio's aura work vertically? [duplicate]

If I play Lucio, can I heal the teammates located at a different height? (roof, upstairs, hovering Pharah... )

In other word is that aura strictly horizontal? Or does it work more like a bubble like Winston's barrier?

If it's horizontal, does it require Line Of Sight or not? (will I heal a nearby ally right behind a wall?)

Lúcio's aura's area of effect is a sphere that surround him. So, yes, if you are flying away with Pharah/Mercy but you are still within the aura's displayed area, you will be healed ONLY if you are also in that sphere. If you are flying in that sphere, Lúcio will heal you. Also, Lúcio needs to have line of sight to heal you, however, you don't need line of sight for the speed song.

Keep in mind while using Lúcio, if you lose line of sight with a teammate, that player will be healed for a limited time before losing the effect (like with Zenyatta's orbs).