 He worked as a research assistant for several years at the Max Planck Institute of Meteorology before completing a Ph.D. in meteorology in 1999 at the University of Hamburg.Timmermann worked as a postdoctoral fellow in the Netherlands and Hawaii before becoming a principal investigator of the DFG Research Group at the Institut fuer Meerskunde in Kiel.In 2004 he moved to Hawaii and worked as an Associate Professor and later Full Professor in the Department of Oceanography, School of Ocean and Earth Science and Technology, University of Hawaii.