I notice this radial striping often when I use the subsurface modifier on shapes with curved segments. How can I prevent it or remove it?
The issue is how the subsurf modifier will subdivide an ngon (a polygon or face made of more than 4 vertices)
The rest of your object is made of quads and subdivides nicely and regularly with the subsurf modifier, whereas the ngon creates a subset of polygons arranged in a way that will create the artifacts you are experiencing.
There are a few solutions:
add a number of subdivisions or loop cuts to make the ngon smaller and the issues less evident:
You can delete the ngon and fill the surface with quads using the grid fill tool (this requires that you have an even number of vertices on the loop ring)
Your problem is the huge ngon on the top. Try filling it with a grid-like patch of mesh.
Check out this topology guide especially the part about Cylinder Caps