A team of scientists from the Center of Excellence in Space Sciences India, and the Tata Institute of Fundamental Research in Mumbai recently uncovered a once unknown link between plasma jets inside of the sun and the sunspot cycle that may foreshadow the hemisphere of the sun’s unequal activity.
Plasma material at different locations inside the sun revolves at different rates powering a dynamo mechanism that creates the magnetic sunspots. According to researchers Lekshmi B., Dibyendu Nandi, and H.M. Antia, asymmetries in plasma jets just below the sun’s surface precede asymmetries in Sunspot activity by about a year.
This discovery has no valid theoretical explanation so far. “The strength of the sun’s torsional oscillation is very small compared to the differential rotation thus making it difficult to measure. Our careful analysis covering 16 years of both ground- and space-based observations has allowed us to discover this link,” said graduate student Lekshmi B.
The team used helioseismology techniques to observe oscillations on the sun’s surface that the propagation of acoustic waves in the interior produces. The process involved using helioseismic techniques to change and tease out plasma velocity in the sun’s two hemispheres.
They probed only the near-surface bands of faster and slower rotation. However, the current consensus is that magnetic fields that form sunspots exist deeper inside the sun. The sunspot cycle asymmetry is across the vast depth of the sun’s convection zone linking the deep and the near-surface layers of the sun.