1 Department of Earth and Planetary Sciences, Rutgers University, New Brunswick, NJ 08854; yingfan@eps.rutgers.edu.
2 Non-Linear Physics Group, Faculty of Physics, Universidade de Santiago de Compostela, E-15782 Santiago de Compostela, Galicia, Spain.
3 Grupo de Estudios Ambientales-Instituto de Matemática Aplicada San Luis, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de San Luis, D5700HHW San Luis, Argentina.
4 Department of Earth System Science, Stanford University, Stanford, CA 94305.
5 Woods Institute for the Environment, Stanford University, Stanford, CA 94305.
6 Precourt Institute for Energy, Stanford University, Stanford, CA 94305.