The Sun’s rotation is a peculiar phenomenon that has long baffled scientists. Unlike what one might expect, its surface exhibits differential rotation, with varying spin rates across different latitudes. Solar physicist Yuto Bekki and his team from the Max Planck Institute for Solar System Research (MPS) have made strides in unraveling this mystery.
Differential rotation extends deep into the solar interior, presenting a puzzle for researchers. However, recent findings suggest that long-period oscillations of sound waves in the solar convection zone may hold the key to understanding this phenomenon. These oscillations, akin to the Sun’s constant ‘humming,’ have been observed to influence the differential rotation.
A groundbreaking discovery by MPS director Laurent Gizon and his team revealed a new type of acoustic oscillation with a 27-day period, suggesting a link to the solar differential rotation. Bekki and colleagues further investigated this relationship and found that the giant sound waves play a crucial role in curbing the differential rotation.
Through three-dimensional numerical simulations, the researchers demonstrated how these oscillations affect the Sun’s behavior. Specifically, oscillation modes at high latitudes transport heat from the poles to the equatorial region, mitigating temperature differences between the two. This process limits the contrast in temperature between the poles and the equator, thereby controlling the Sun’s differential rotation.
According to Gizon, this temperature balance, albeit minuscule in the context of the Sun’s extreme temperatures, significantly influences its global dynamics. The interplay between high-latitude oscillation modes and the differential rotation resembles atmospheric instabilities that produce cyclonic storms on Earth.
While many mysteries surrounding the Sun persist, this discovery marks a significant step toward understanding its complex dynamics. The findings not only shed light on the mechanisms driving the Sun’s rotation but also offer insights into similar processes occurring in other stars. As scientists continue to probe the depths of space, unraveling the mysteries of celestial bodies like the Sun brings us closer to unlocking the secrets of the universe.
