Hierarchical Locally Recoverable Codes on surfaces

We construct locally recoverable codes with hierarchy from surfaces in ${\mathbb{A}}^3$ admitting a fibration by curves of Artin-Schreier or Kummer type. We derive the parameters of our codes by leveraging the geometry and arithmetic of the fibration, which is obtained by projection onto one of the coordinates. As a byproduct, we obtain estimates for (and in one case an explicit count of) the number of rational points in certain families of surfaces.