The "Saruhashi Prize," which honors outstanding female scientists, was awarded to Associate Professor Yukiko Imada at the University of Tokyo's Atmosphere and Ocean Research Institute (AORI). She was recognized for her contributions to the development of "Event Attribution," a method for analyzing the factors behind extreme weather. The announcement was made by the "Association for the Bright Future of Women Scientists" (chaired by Tomoko Nakanishi).
The reason for the award is her research on the causal analysis of recent climate change and extreme weather. The cause of extreme weather is not always limited to global warming caused by human activity. It can also be related to long-term variations, such as the "El Niño phenomenon," whose main cause is accidental atmospheric fluctuations and where sea surface temperatures rise from the equatorial Pacific near the date line to the coast of South America. It is essential to scientifically separate these factors and evaluate the human-made influence. The new method, Event Attribution, emerged in the mid-2000s. Imada's achievement was applying this method to the Japanese archipelago, where conditions are highly complex, and making it function effectively.
In "Event Attribution," the word "attribution" means "assigning a cause." Using climate models, researchers simulate a hypothetical world where "global warming did not occur" and repeat calculations under various conditions. In this way, they calculate the probability of extreme weather occurring and compare it with the real world. The change in probability due to human activity is then presented in terms such as "the probability of this phenomenon occurring has increased by X times."
Japan experiences distinct seasonal changes due to monsoons, typhoons, extreme heat, and heavy snow. Combined with its mountain ranges and being surrounded by the sea, the conditions are complex, and such analysis was thought to be difficult. However, Imada solved this by independently developing Event Attribution using high-precision, large-scale climate simulations. In particular, she made it possible to analyze heavy rain at a regional scale. For example, regarding the heavy rain in western Japan in July 2018, she revealed that the probability of its occurrence had increased 3.3 times due to the influence of global warming.
Dr. Syukuro Manabe, who won the Nobel Prize in Physics in 2021, laid the foundation for model research that reproduces complex climates on computers. He also modeled the mutual influence between the atmosphere and the ocean, achieving highly reliable warming predictions. Imada follows this lineage, investigating the link between global-scale climate change and regional extreme weather, and has pioneered Event Attribution research in Japan. Her work has also expanded into international joint research.
The association stated: "Associate Professor Imada has communicated the results of Event Attribution to society and supported activities calling for measures against global warming by providing a scientific basis. While international efforts to mitigate global warming are not necessarily showing sufficient progress under the current world situation, the evaluation of scientifically backed extreme weather risks and their accurate communication to society is a mission required of scientists and is highly valued."
At a press conference on the 20th of last month, Imada said: "I am deeply moved by this award, and it makes me feel a renewed sense of responsibility. I have liked science since I was a child. I grew up on a mountain in Nagasaki where the night sky was beautiful, and I had a dream of becoming an astronaut until about high school. At the University of Tokyo, I met a professor of climate change whom I wanted to follow, and I stepped into this field. I find research rewarding because climate models can create information that cannot be obtained from real observation data. Actually, the research I want to dedicate my life to is not Event Attribution, but what that is remains a secret for now."
She also spoke about her thoughts as a female researcher. "My senior professors fought for us, so by the time I started my research, the environment was already quite well-prepared. While social bias might not be zero, I haven't often felt that being a woman was a disadvantage. However, there are innate differences. I felt that women cannot project the same kind of power that men do when presenting, so I have tried various ways to adapt. Also, when I was younger, 'nominication' (communication through drinking sessions) was still important, and sometimes important things were decided in that male-specific atmosphere. Thanks to being too busy with child-rearing and research, I didn't have time to dwell on my failures, which was a good thing."
PROFILE
Born in 1978 in Nagasaki, Japan. Graduated from the Department of Earth and Planetary Physics, Faculty of Science, the University of Tokyo. Completed a Master's degree in the Department of Earth and Planetary Science, Graduate School of Science, at the same university. After working for a company, she completed her doctoral course. After serving as a Project Assistant Professor at the Atmosphere and Ocean Research Institute and a Senior Researcher at the Meteorological Research Institute of the Japan Meteorological Agency, she has held her current position since April 2023.
The association was established through a fund by Dr. Katsuko Saruhashi, a geochemist, and this year marks the 46th time the prize has been awarded. The presentation ceremony will be held in Tokyo on the 23rd.
Original article was provided by the Science Portal and has been translated by Science Japan.