  Naturally stable to ELMs, and with widths larger than EPED predictions, the
I-modes are an excellent laboratory for investigating the role of drift
micro-instabilities in pedestals since I-mode pedestal are not "limited" by MHD
instabilities. We present here a study based on gyrokinetic simulations (using
GENE) to model fluctuations and heat transport in the I-mode pedestals in
C-Mod. We find the Weakly Coherent Mode observed on C-Mod I-mode to be an
electrostatic Ion Temperature Gradient/Impurity density gradient (ITG/Impurity)
driven mode. The ITG/Impurity mode match frequency and the impurity confinement
time observed on the I-mode. Nonlinear ETG simulations, can match experimental
heat flux with profile adjustment well within experimental error bars.
Simulations, varying impurity level (Zeff) and temperature and density profiles
(within experimental error bars), are used to probe the sensitivity of
fluctuations and transport.
