In a world first, Japanese researchers used the Fugaku supercomputer to replicate the rotational imbalances of the sun, a phenomenon that has puzzled astronomers for centuries.
Scientists at Chiba University and Nagoya University simulated the inner workings of the gas ball in an attempt to determine why different areas spin at different speeds.
Their results were published in the scientific journal Nature Astronomy at (https://doi.org/10.1038/s41550-021-01459-0).
All regions of the Earth complete one revolution in 24 hours.
But it takes about 25 days for areas near the sun’s equator to complete a rotation and about 30 days for areas near the north and south poles.
The phenomenon, known as solar differential rotation, was first observed around 1630, according to Chiba University. But there is still no definitive explanation as to why this is happening.
Using about 5.4 billion points inside the sun, Fugaku calculated how the energy of nuclear fusion inside the star is transferred to the surface by convection currents.
The project simulated thermal migration and magnetic field changes based on observational data on the density, pressure and temperatures of the sun.
The high-definition simulation succeeded in reproducing the equator rotating faster than the north and south poles, the scientists said.
Fugaku’s predecessor, the K supercomputer, could perform calculations using only around 100 million points, and it was unable to accurately reproduce the sun’s complicated inner workings.
This experiment erroneously made the equator spin at a slower rate than the poles.
The Fugaku supercomputer could help researchers shed light on another mystery.
The difference in rotational speed is believed to play a key role in the emergence of more sunspots and increased solar activity every 11 years.
“We will also work to understand the mechanism of the 11-year cycle – the biggest mystery in solar physics,” said Hideyuki Hotta, associate professor of physics at Chiba University.