Helioseismic Diagnostics of the Solar Interior Dynamics and Dynamo (NOTE the unusual TIME)

by Alexander Kosovichev (New Jersey Institute of Technology)

Tuesday 22 Mar 2022, 17:00 → 18:00 Europe/Stockholm

https://stockholmuniversity.zoom.us/j/940229961

Helioseismic data from Solar and Heliospheric Observatory (SoHO) and Solar Dynamics Observatory (SDO) allow us to probe the physical properties of the solar interior dynamics and dynamo. In particular, solar rotation variations in the convection zone inferred by global helioseismology for two sunspot cycles reveal migrating patterns of zonal acceleration, providing evidence for Parker’s dynamo waves. In addition, the data show that the near-surface shear layer (NSSL) is essential for the formation of the magnetic butterfly diagram. The migrating zonal flows (‘torsional oscillations’) as well as variations of the meridional circulation observed by local helioseismology form an ‘extended’ 22-year solar cycle, putting important constraints on theoretical models. Furthermore, analysis of spectral properties of solar convection in the NSSL reveals a rapid increase of the horizontal flow scales with depth, from supergranulation to giant-cell scales, and shows a complex correlation of the total power of subsurface convective flows with the solar activity cycle.

https://ui.adsabs.harvard.edu/abs/2022arXiv220100638G/abstract

Kosovichev_2022-03-22.mp4