2026 Volume 21 Article ID: 1401038
Understanding the interaction between plasma turbulence and zonal flow is essential for structure formation and transport regulation in magnetically confined plasmas. Using experimental data from the PANTA linear plasma device, we reduce the high-dimensional dynamics of numerous modes into two variables: turbulence and zonal. We then identify prominent intermittent bursts localized in the zonal-flow component—a phenomenon that, to the best of our knowledge, has not been reported previously. These bursts appear as impulsive, positive-going, low-frequency excursions superimposed on rapid background fluctuations. To address this non-stationarity, we investigate two approaches: a model-driven approach and a data-driven approach. We use a generalized Predator-Prey (P-P) model identified via an adaptive extended Kalman filter to track the evolution of time-varying physical parameters, and we also apply a Time-Varying Coefficient Vector Autoregressive model (TV-VAR) to achieve high-fidelity tracking of the sharp, transient burst dynamics. A distinct reorganization of the directed coupling structure is observed following burst events, including a transition to a regime in which zonal-flow regulation of turbulence becomes transiently dominant. These results indicate that time-varying interaction measures may provide informative features for burst forecasting and offer a basis for understanding regime transitions in transient plasma dynamics.
