1. E. R. Weeks, J. S. Urbach, H. L. Swinney, Center for Nonlinear Dynamics and Department of Physics, University of Texas at Austin, Austin, TX 78712, USA.
2. Y. Tian, K. Ide, M. Ghil, Department of Atmospheric Sciences and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90095, USA.