I'm looking for some references on the following situation:
$S$ is a Riemannian surface, and $G_n$ is a sequence of metric subgraphs embedded on $S$. Let $\zeta_n$ be the zeta function of the Laplacian of $G_n$ (Mellin transform of $Tr (h_t) - 1$, where $h_t$ is the heat kernel of $G_n$), and let $\zeta_S$ be the Minakshisundaram–Pleijel zeta function of $S$.
Under what conditions and for what modes of convergence do we have $\zeta_n(s) \to \zeta(s)$, $\zeta_n'(s) \to \zeta'(s)$, etc.
I'm particularly interested in the convergence of $exp( - \zeta_n'(0) ) / |G_n| \to exp( - \zeta'(0)) / Vol(S)$.
(This relates to my question here: Does the zeta regularized Laplacian determinant measure the volume of some parameter space? How many "spanning trees" on a manifold? )