The dynamics of small-scale magnetic fields modulated by the solar cycle
Speaker: Dr. Marco Stangalini
Jul 8, 2025 11:00 PDT
The dynamics of small-scale solar magnetic elements is usually studied over short temporal windows, such as a few hours. This approach, however, fails to offer a comprehensive understanding of their behavior within the broader context of the Sun’s larger-scale dynamics. These magnetic elements, influenced by plasma flows and convection, serve as conduits for wave energy, contributing to solar wind acceleration. Data from the Helioseismic and Magnetic Imager (HMI) on NASA’s Solar Dynamics Observatory (SDO) have enabled the study of small-scale magnetic field dynamics over extended periods. This seminar presents the novel discovery of a modulation in the behavior of small-scale magnetic concentrations in the photosphere, aligning with the 11-year solar activity cycle. Additionally, a temporal variation in the polarization of their oscillations has been observed, indicating the influence of the global dynamo on these dynamics. These findings are based on automated tracking of over 31 million magnetic concentrations over 11 years, marking the most comprehensive statistical analysis of its kind.