  We use a global magnetohydrodynamic simulation of a geometrically thin
accretion disk to investigate the locality and detailed structure of turbulence
driven by the magnetorotational instability (MRI). The model disk has an aspect
ratio $H / R \simeq 0.07$, and is computed using a higher-order Godunov MHD
scheme with accurate fluxes. We focus the analysis on late times after the
system has lost direct memory of its initial magnetic flux state. The disk
enters a saturated turbulent state in which the fastest growing modes of the
MRI are well-resolved, with a relatively high efficiency of angular momentum
transport $< < \alpha > > \approx 2.5 \times 10^{-2}$. The accretion stress
peaks at the disk midplane, above and below which exists a moderately
magnetized corona with patches of superthermal field. By analyzing the spatial
and temporal correlations of the turbulent fields, we find that the spatial
structure of the magnetic and kinetic energy is moderately well-localized (with
correlation lengths along the major axis of $2.5H$ and $1.5H$ respectively),
and generally consistent with that expected from homogenous incompressible
turbulence. The density field, conversely, exhibits both a longer correlation
length and a long correlation time, results which we ascribe to the importance
of spiral density waves within the flow. Consistent with prior results, we show
that the mean local stress displays a well-defined correlation with the local
vertical flux, and that this relation is apparently causal (in the sense of the
flux stimulating the stress) during portions of a global dynamo cycle. We argue
that the observed flux-stress relation supports dynamo models in which the
structure of coronal magnetic fields plays a central role in determining the
dynamics of thin-disk accretion.
