Resonance and limit cycle in a noise driven Lorenz model
  The effect of an external noise on the Lorenz model is investigated near the onset of convection and near the Hopf bifurcation. We show the existence of a diverging time scale near the onset of convection and a resonance near the Hopf bifurcation. Our calculation provides an understanding of the noise induced stabilization of the limit cycle that had been observed numerically. 
Himadri S. Samanta and J. K. Bhattacharjee