Chiba University announced that it was the first in the world to elucidate the mechanism that creates the "solar cycle of 11 years" by the ultra-high resolution calculation made possible by the supercomputer "K computer".This result was published in the American scientific journal "Science" by an international research group including Hideyuki Hotta, a specially appointed assistant professor at the Graduate School of Science, Chiba University, and Hiroaki Yokoyama, an associate professor at the Graduate School of Science, the University of Tokyo.

 The sun has a strong magnetic field region called sunspot, and the number of sunspots fluctuates every 11 years depending on the activity of the sun.However, the mechanism has not been clarified and it was called "the oldest mystery of the sun".It is also suggested that the earth was cold in the 1600s, during the period of about 70 years when there were no sunspots, and it is urgent to clarify this mystery when considering the global environment.

 The magnetic field is thought to be generated by turbulence inside the Sun, but the process of creating an orderly large-scale magnetic field that creates an 11-year cycle has been elucidated from the highly chaotic turbulence. not.This time, the research group has developed a calculation method "sound velocity suppression method" that reduces the load. Ultra-high resolution calculation by "K computer" was performed.

 Until now, it has been said that "the higher the turbulence, the larger the magnetic field cannot be created."Even with this calculation, up to a certain resolution, the results were as expected so far.However, in the ultra-high resolution realized this time, the small-scale magnetic field generation became very active, exceeding the energy of the small-scale turbulent motion.This refers to the state where "the turbulence is no longer high despite the high resolution".As a result, even in highly turbulent situations such as the sun, only ordered large-scale flows are allowed, and large-scale magnetic fields have been successfully developed.

 This mechanism is supposed to work in the actual sun, and it can be said that the basic and important mechanism for solving the problem of the solar cycle has been clarified.In the future, it is expected that the oldest mystery of the sun will be solved in earnest by confirming the details of the theory through observations centered on satellites.

Tokyo University

Established in the 10th year of the Meiji era.A university with the longest history in Japan and at the forefront of Japanese knowledge

The University of Tokyo was established in 1877 (Meiji 10) by integrating the Tokyo Kaisei School and the Tokyo Medical School.Since its establishment, it has developed education and research in a unique way in the world as a leading university in Japan and an academic center for the fusion of East and West cultures.As a result, many human resources have been produced in a wide range of fields, and many research achievements […]

Chiba University

Fostering human resources who will open up the next generation.To a future-oriented university that shines in the world

Chiba University has 10 faculties, 7 graduate schools / faculties, and a large number of affiliated facilities, and has specialized knowledge and skills, high problem-solving ability, high intelligence, ethical standards, and rich humanity, and has an interdisciplinary perspective. We aim to develop human resources who can play an active role internationally.Actively promote the enhancement of liberal arts education and the internationalization of educational activities, which are the basis of this […]

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