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Interaction between a magnetic island and turbulence has been intensively studied in recent years with advance of plasma diagnostics in various plasma experiment devices such as LHD, J-TEXT, TJ-II, DIII-D, KSTAR, and HL-2A. Simultaneous measurements of plasma turbulence and pressure and flow profiles have provided a comprehensive understanding of their interaction. Experiments found that plasma turbulence becomes strongly inhomogeneous around a magnetic island due to the combined effect of the pressure gradient (driver) and flow shear (regulator) modifications by the island. Those experimental observations are consistent with gyrokinetic simulations results obtained using GKW, GTC, GENE, and gKPSP, and imply the limitation of conventional understanding of the island evolution. The effect of inhomogeneous and nonlinear characteristic of plasma turbulence would complicate the island evolution which depends on ambient transport physics. In addition, more complex turbulence phenomena which can affect the island stability in fusion plasmas as well as the underlying magnetic reconnection process have been suggested from theoretical and numerical studies. Some of them whose experimental evidences are being accumulated from both fusion and laboratory plasmas are introduced; turbulence spreading, nonlinear mode coupling, turbulence driven flow, and turbulent magnetic reconnection. They can either suppress or facilitate the island growth. Since turbulence spreading and turbulent magnetic reconnection can be a universal feature of magnetized plasmas, their observations would provide general physical insights into the island turbulence dynamics.

We present that a statistical method known as the Complexity-Entropy analysis is useful to characterize a state of plasma turbulence and flux in the resonant magnetic perturbation (RMP) edge localized mode (ELM) control experiment. The RMP ELM suppression phase with the stochastic pedestal top temperature fluctuation can be distinguished from the natural ELM free phase with the chaotic fluctuation. It is discussed that the stochastic temperature fluctuation localized near the pedestal top can be originated from the narrow layer of the field penetration near the pedestal top. The forced magnetic island can emit the resonant drift wave of comparable sizes (relatively low-k) in the RMP ELM suppression phase, and it can results in the generation of stochastic higher wavenumber fluctuations coupled to tangled fields around the island. The analysis of the ion saturation current measurement around the main outer striking point on the divertor shows that it also becomes more stochastic as the stronger plasma response to the RMP field is expected.