Dr. Toshio Yamagata started his career in the field of Geophysical Fluid Dynamics in 1973 and has published about 200 articles in peer-reviewed international journals in the fields of physical oceanography and climate dynamics. His early work includes introduction of a new geostrophic regime called “Intermediate Geostrophic Dynamics” and its application to explanation of longevity of anticyclonic eddies in the oceans and the Jovian atmosphere in the 1970s, and a simple mathematical model for El Niño/Southern Oscillation (ENSO) in early 1980s. From the late 1980s to the 1990s, with active graduate students and postdoctoral fellows, he concentrated his efforts on making the general ocean circulation model more realistic and, by use of both the model simulation and the accumulated ocean-atmosphere data, clarified formation mechanisms of several large-scale upwelling phenomena. Those are Costa Rica Dome, Mindanao Dome, Dakar Dome, Angola Dome, Sri Lanka Dome, and, more recently, the Seychells Dome. The outcome of ocean modeling activities with his colleague Dr. Yasumawa Miyazawa is the state-of-the art ocean prediction system called JCOPE (http://www.jamstec.go.jp/ frcgc/jcope/).
Dr. Yamagata’s most well-known scientific contribution is the discovery with his Indian colleagues of a coupled ocean-atmosphere phenomenon in the tropical Indian Ocean in 1999, which was named the Indian Ocean Dipole (IOD). The impacts of IOD on the world climate and societies have turned out to be huge like ENSO. In the 2000s, with colleagues of JAMSTEC, he developed an experimental seasonal prediction system by use of the SINTEX-F coupled model and achieved the best performance of the seasonal prediction in 2009. With Dr. Swadhin Behera, he also discovered the Subtropical Indian Ocean Dipole (SIOD) in the southern Indian Ocean. The relation between the SIOD and the South African anomalous rainfall led him to introduce the Japan-Republic of South Africa bilateral project under SATREPS (http://www.jst.go.jp/global/english/index.html), which was entitled “Prediction of Climate Variations and its Application in the Southern African Region (http://www.jamstec.go.jp/apl/satreps_sa/e/)” for an early warning system by use of the Oversea Development Aid (ODA) of Japanese Government in 2009. His most recent research topics are “El Niño Modoki” in the changing climate, and coastal ocean-atmosphere coupled modes such as Ningaloo Niño/Niña, California Niño/Niña and Dakar Niño/Niña. This new initiative will contribute to improving prediction skills of the seasonal prediction system.
After retiring from Dean of School of Science, the University of Tokyo, he is affiliated with Japan Agency for Marine-Earth Science and Technology as director of Application Laboratory (http://www.jamstec.go.jp/apl/e/; http://www.jamstec.go.jp/res/ress/yamagata/). He is working also at the crossroads of ocean science and policy as vice president of Japan Society of Ocean Policy (http://blog.canpan.info/kaiseiken/) and chief editor of Ocean Newsletter of Ocean Policy Research Institute of the Sasakawa Peace Foundation (https://www.spf.org/e/; http://www.sof.or.jp/en/index.php). Based on his career in oceanography and climate research as described above, he is advocating importance of SIMSEA (Sustainability Initiative in the Marginal Seas of South and East Asia) program of the International Council for Science (ICSU) Regional Office for Asia and the Pacific (ROAP) to conserve marine health in Asia and the Pacific.