Dr. Taroh Matsuno : 3. The Earth inside the Computer

3. The Earth inside the Computer

A New Team

During the 1970 and 1980s, environmental issues such as the depletion of the ozone layer and increasing global warming were recognized as global issues. Understanding the importance of these issues, the Japanese government established new research organizations to create a firm foundation for scientific studies and initiated large-scale research projects. Dr. Matsuno, who was eager to create an environment where advanced research could be conducted in Japan, became involved with a number of research teams and took a leading role in advancing research in Japan.

Center for Climate System Research, University of Tokyo (CCSR)

Established as a hub for environmental research, the Center for Climate System Research (CCSR) at the University of Tokyo was founded. Dr. Matsuno served as the head of the center until 1994. The center had 10 staff members, including four professors, four associate professors, and two research assistants. It served as a shared facility for universities nationwide and was an independent organization separate from the faculties at the University of Tokyo. The center played a central role in climate research across Japan and made contributions to the creation of the IPCC's 3rd, 4th, and 5th assessment reports.

Graduate School of Environmental Science, Hokkaido University

In 1994, Dr. Matsuno was appointed as the head of the Course in Atmospheric-Ocean and Climate Dynamics, at Graduate School of Environmental Science, Hokkaido University. This was a fantastic place that brought together researchers from various universities across Japan and abroad, all eager to embark on new endeavors. During lunchtime, everyone engaged in active discussions, and thanks to these interactions, Dr. Matsuno was able to acquire new knowledge, particularly in matters related to oceans.

The Frontier Research System for Global Change (FRSGC)

The Frontier Research System for Global Change (FRSGC) was established by the former Science and Technology Agency as a large-scale research project to address climate change and global environmental issues. Dr. Matsuno served as the system head of the FRSGC, leading the establishment of this new research system. The goal was to bring about the prediction of global change, and clarify the mechanisms of change in six fields, such as climate, the water cycle, and ecosystems, and reproduce them on a computer.

Computer programs that reproduce real-world phenomena on a computer for predictions and validations are called simulation models. The development of systems to simulate the atmospheric conditions within computers for weather forecasting started in the 1960s. By the 1990s, simulation models could be used to reproduce not only weather but also various events such as the movement of ocean currents, and changes in ecosystems.

Earth Simulator Project

Can you imagine what it takes to simulate real-world phenomena such as the atmosphere and ocean currents, which appear to be extremely complex? Let's consider the case of the atmosphere.

The state of atmosphere is determined by a wide variety of factors such as temperature, wind, pressure, and amount of vapor present. Interestingly, the changes in each of these factors do not occur randomly; they follow specific laws of physics. These laws can be expressed through mathematical equations. By applying these equations to a computer simulation, it is possible to calculate and reproduce the changes that will occur in the near future, from the current state. If we can predict the state five minutes into the future, we can then predict what happens in 10 minutes, 1 hour, 24 hours, 1 year, and so on, into the distant future. In a computer simulation, the passage of time can be accelerated compared to the real world, allowing us to predict the state 30 years ahead without waiting for 30 years to elapse. In practice, weather forecasting focuses on predicting meteorological conditions from tomorrow to a week ahead, while climate prediction extends to average conditions several months or more into the future.

It's easy to say, but calculating various factors for all locations on Earth requires a computer with extraordinary power. In a simulation model, the entire Earth is not calculated at once; instead, the Earth is divided into a fine mesh, and calculations are conducted for each mesh or grid cell. The accuracy of the simulation of the Earth's state depends on how fine that mesh is. The smaller the grid area, the more accurate the simulation, but it also requires more computing power.

In Japan, a project to develop the world's fastest supercomputer, the "Earth Simulator, " was launched in 1997 based on a proposal from a conference chaired by Dr. Matsuno. At that time, simulation models globally employed a 100 x 100 km grid cell size, but the newly developed Earth Simulator became the first in the world to enable climate change predictions using a 20 x 20 km grid cell size.

From 2002, under Dr. Matsuno's leadership, research on climate change predictions using the Earth Simulator was conducted, and the results were featured in the IPCC Fourth Assessment Report as simulation outcomes from one of the highest resolution models.

Dr. Matsuno with the Earth Simulator

To Future Researchers

What Dr. Matsuno wants to convey to young people aspiring to become researchers is that they should find research topics that intrigue them. He also emphasizes the importance of dedicating oneself to cutting-edge science and contributing to society. Many challenges still remain in the field of global warming and climate change prediction. Let's confront our own questions and work together with our colleagues to tackle these difficult problems.

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Understanding