Several Flat Eathers now have tried to claim that a 'column of light' cannot possibly form on a convexly curved Earth - which is just ridiculous but here we go… all will become clear.
This one I personally took on a sharply convexly curved overpass. Clear columning is observed along the convexly curved surface.
Here we observe it with sunlight all the way over the very clearly convexly curved wave!
And here is a diagram showing why.