  Molecules and dust produced by the atmospheres of cool evolved stars
contribute to a significant amount of the total material found in the
interstellar medium. To understand the mechanism behind the mass loss of these
stars, it is of pivotal importance to investigate the structure and dynamics of
their atmospheres.
  Our goal is to verify if the extended molecular and dust layers of the
carbon-rich asymptotic giant branch (AGB) star V Oph, and their time
variations, can be explained by dust-driven winds triggered by stellar
pulsation alone, or if other mechanisms are operating.
  We model V Oph mid-infrared interferometric VLTI-MIDI data ($8$-$13~\mu$m),
at phases $0.18$, $0.49$, $0.65$, together with literature photometric data,
using the latest-generation self-consistent dynamic atmosphere models for
carbon-rich stars: DARWIN.
  We determine the fundamental stellar parameters: $T_\text{eff} = 2600~$K,
$L_\text{bol} = 3585~$L$_{\odot}$, $M = 1.5~$M$_{\odot}$, $C/O = 1.35$,
$\dot{M} = 2.50\cdot10^{-6}$M$_{\odot}$/yr. We calculate the stellar
photospheric radii at the three phases: $479$, $494$, $448$ R$_{\odot}$; and
the dust radii: $780$, $853$, $787$ R$_{\odot}$. The dynamic models can fairly
explain the observed $N$-band visibility and spectra, although there is some
discrepancy between the data and the models, which is discussed in the text.
  We discuss the possible causes of the temporal variations of the outer
atmosphere, deriving an estimate of the magnetic field strength, and computing
upper limits for the Alfv\'{e}n waves velocity. In addition, using
period-luminosity sequences, and interferometric modeling, we suggest V Oph as
a candidate to be reclassified as a semi-regular star.
