Mu Mu Mu Mu, born in 1954 in Dingyuan City, Anhui Province, PhD, atmospheric dynamics sicentist. He was elected academician of the Chinese Academy of Sciences (CAS) in 2007 and academician of the Academy of Sciences for the Developing World in 2008. He is currently the deputy director of the academic committee of Institute of Atmospheric Physics, CAS， and the director of the academic committee of Key Laboratory of Ocean Circulation and Waves, CAS. He applied modern mathematics theories and approaches to the innovative studies on weather and climate predictability, and the nonlinear stability and sensitivity of atmospheric and ocean motion and obtained indepth and original results. He proposed a new method “conditional nonlinear optimal disturbance (CNOP)” to study predictability and therefore initiated further research and exploration on the method in the international community. The method is commented as “a new method” to study nonlinear effect because “the CNOP considers the nonlinear growth of errors and probably better characterizes the nonlinear nature of the real world.” He and his collaborators used CNOP to study the predictability of El Nino, and demonstrated that the CNOPtype error can cause a notable Spring Predictability Barrier (SPB) for El Nino events. They also revealed that the spatial pattern of the initial error is one main cause of the SPB. This work was highly recognized by a paper on the international journal, “if the CNOPtype errors are measured and then removed from raw predictions, the better skills of predictions might be able to be realized.” Concerning the thermohaline circulation (THC) in the climate change, he and his collaborators used CNOP to reveal a nonlinear feedback mechanism relying on initial perturbations, and showed that the nonlinear process is one cause of THC sensibility to fresh water flux perturbation. And this work is regarded as “exciting new discoveries” research and “another possible extension is to address nonlinear behavior.” Recently, he applied the CNOP method to the targeted observation research on typhoons and other extreme weather events, and overcame the limit of traditional LSV in determining sensitive areas of targeted observation. He established several nonlinear stability criteria for the famous quasigeotropic motion model, and overcame the difficulties in the establishment of Arnold’s second stability criterion. His contribution, together with other related findings in the international community, is recognized to have “a great improvement in our understanding of the stability mechanism of geophysical fluids.” He has won a number of awards, including the National Science Fund for Distinguished Young Scholars, the Youth Prize of China Association for Science and Technology, and CAS First Prize of “Natural Sciences Award” (the first completer). He is (was) a member of the International Committee on Dynamic Meteorology (ICDM) of the IAMAS, a member of the International Commission on Planetary Atmospheres and their Evolution (ICPAE) of the IAMAS, a member of the editorial committee of the Q. J. Roy Meteor. Soc. of UK, a member of the editorial committee of Science in China (Series D), and the member and the convenor of the sixth referee panel for atmospheric sciences of the State Department Diploma Committee.