Noise enhanced the preponderant oscillation

Explicit internal signal stochastic resonance (EISSR) is investigated in the Willamowski-Rössler reaction model located in the dynamical region of periodic-2 oscillations, which subjects to Gaussian white noise. The z-variable's output signal-to-noise ratio (SNR) as a function of the noise intensity shows non-monotonic behavior, indicating the occurrence of EISSR. It is first found that EISSR happened in the periodic-2 oscillations state. When the system exist two intrinsic signals, noise can enhance the preponderant oscillation signal.