Tag Archives: magnetic field

196. Observations of Rossby wave parameter variations during solar cycle 24

Contributed by Mattias Waidele. Posted on September 25, 2023

Equatorial Rossby waves are detected using the HMI’s time-distance subsurface flow fields. It is also found that the power of the Rossby waves show a positive correlation with the sunspot number, while the frequency of the waves shows an anti-correlation with the sunspot number.

194. Rossby waves and the organization of photospheric magnetic fields

Contributed by Breno Raphaldini. Posted on September 20, 2023

HMI magnetic field synoptic maps are used to evaluate the magnetic field structures’ organization and propagation as a function of time and latitude. It is demonstrated that the organization of longitudinal structures observed on synoptic maps is proportional to the level of activity at given latitudes.

186. Solar-Cycle Variation of quiet-Sun Magnetism and Surface Gravity Oscillation Mode

Contributed by Andreas Korpi-Lagg. Posted on October 17, 2022

Twelve years of HMI Dopplergram and magnetogram data have been used to uncover the solar cycle dependence of the magnetically quietest regions on the Sun and to reveal an enigmatic behavior of the surface-gravity wave energy contained in those regions.

182. The magnetic topology of the inverse Evershed flow

Contributed by Avijeet Prasad. Posted on July 29, 2022

Inverse Evershed flow is derived from chromospheric observations. Coupling these flow with the non force-free model, the authors find that the flow is driven along magnetic field lines connecting network elements with the outer penumbra by a gas pressure difference.