Scientists from the Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital, and IIT Delhi have developed a new method to detect hidden turbulence in the Sun’s corona, potentially providing fresh clues to one of solar physics’ biggest puzzles — why the corona is much hotter than the Sun’s visible surface.
The corona is permeated by magnetic structures carrying Alfvénic, or kink, waves.
However, the new study shows that these waves can also produce asymmetric spectral signatures.
This is significant because blueward asymmetries observed in solar spectral lines have often been associated with upward plasma flows, jets or other mass motions.
Transverse waves, being nearly incompressible, were not generally expected to produce such effects.
Scientists from the Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital, and IIT Delhi have developed a new method to detect hidden turbulence in the Sun’s corona, potentially providing fresh clues to one of solar physics’ biggest puzzles — why the corona is much hotter than the Sun’s visible surface.
The study, published in The Astrophysical Journal, used three-dimensional magnetohydrodynamic simulations and forward modelling to show how transverse waves travelling through the corona’s magnetic structures can produce distinctive changes in spectral lines.
The corona is permeated by magnetic structures carrying Alfvénic, or kink, waves. As these waves move outward along magnetic field lines, they cause the structures to sway sideways. Scientists have traditionally associated such waves with alternating red and blue Doppler shifts, reflecting plasma motion towards and away from observers.
However, the new study shows that these waves can also produce asymmetric spectral signatures. This is significant because blueward asymmetries observed in solar spectral lines have often been associated with upward plasma flows, jets or other mass motions. Transverse waves, being nearly incompressible, were not generally expected to produce such effects.
