The Sun, a colossal sphere of hot plasma, exhibits a mesmerizing yet strict rhythm defined by its magnetic activity. This activity is not erratic but follows a cyclic variation that peaks approximately every eleven years. Central to this rhythm are two enormous circulations of plasma, one in each solar hemisphere, which orchestrate the dynamics of the solar magnetic field. Near the Sun’s surface, plasma flows transport magnetic field lines from the equator toward the poles, while in the solar interior, these flows return to the equator, establishing a vast and complex heliophysical system.
Despite our extensive studies of the Sun, critical details about this complex solar “magnetic field conveyor belt” remain poorly understood. The processes occurring at the Sun’s poles are of paramount importance in this context. However, viewing these regions from Earth proves challenging due to our limited perspective; scientists can only glean minimal insights. Most space probes have similarly restrictive vantage points, which complicates efforts to unlock the mysteries related to the Sun’s magnetic behavior.
Sami Solanki, the director of the Max Planck Institute for Solar System Research (MPS) and co-author of a recent study, emphasizes the importance of understanding the Sun’s magnetic cycle. He points out that comprehending the dynamics at the Sun’s poles is crucial to filling the knowledge gaps that have long hindered our comprehension of solar activity. This vacuum of knowledge is being addressed by the groundbreaking work of the Solar Orbiter spacecraft, which has been in operation since February 2020.
The Solar Orbiter is on an ambitious mission, traveling in elongated ellipses around the Sun to provide data that could unveil the enigmas lurking in these high-latitude regions. In March 2021, the Solar Orbiter transcended the plane where the planets, along with nearly all other space probes, orbit the Sun. This trajectory, tilted at an impressive 17 degrees, enables the spacecraft to gather unprecedented views of the Sun’s polar areas for the first time in human history.
The recently released findings, documented in a publication in the Astrophysical Journal Letters, outline an illuminating examination of data obtained from Solar Orbiter’s Polarimetric and Helioseismic Imager (PHI) and Extreme-Ultraviolet Imager (EUI). The data, collected during a critical window from March 16 to March 24, 2021, furnish key insights about the direction of plasma flows and the magnetic field defining the solar surface, offering a more nuanced understanding of solar dynamics.
In a remarkable development, researchers were able to refine the depiction of the supergranulation and magnetic network that covers the Sun’s south pole, a feat previously unattained. Supergranules, massive cells of hot plasma approximately two to three times the size of Earth, create an intricate tapestry across the solar surface. Through their horizontal movements, these supergranules facilitate the transportation of magnetic field lines to their peripheries, effectively generating the Sun’s magnetic network—a complex web of robust magnetic fields.
Conversely, researchers were surprised to discover that the magnetic field at the poles drifts toward these high latitudes at rates averaging between 10 to 20 meters per second. This rate of migration is unexpected, as previous research focusing on observations from the ecliptic plane had reported considerably slower drifts of the magnetic field in polar regions. The implications of these discoveries are profound, as the patterns of magnetic field migration offer critical clues regarding the Sun’s overarching plasma and magnetic field circulatory systems.
Lakshmi Pradeep Chitta, the research group leader at MPS and the first author of the study, highlights the significance of these findings. He describes the supergranules at the poles as invaluable tracers that have shed light on the polar components of the Sun’s global, eleven-year magnetic circulation for the very first time. This momentous achievement pushes the boundaries of our understanding and raises a plethora of questions concerning the operational dynamics of the Sun’s predominantly elusive north and south poles.
As remarkable as these discoveries may be, the question of whether the Sun’s global magnetic conveyor belt decelerates in the vicinity of the poles remains unanswered. The presently available data offer only a fleeting snapshot of the expansive solar cycle. To answer these pressing questions definitively, further observational data is warranted, ideally spanning long durations to capture the full cadence of solar activity.
In conclusion, the unveiling of these magnetic dynamics at the Sun’s poles marks a pivotal advancement in the field of solar research. Driven by the capabilities of the Solar Orbiter spacecraft, researchers now have a novel lens through which to observe and comprehend the influences dictating solar activity. This refinement of our understanding reinforces the essential connection between solar phenomena and their impacts on our planet’s environment, emphasizing the importance of continued exploration and inquiry into the Sun’s magnetic mechanics.
Additionally, as we stand on the precipice of a new chapter in solar study, the importance of international collaboration among scientific communities cannot be understated. With expanding data and improved models, we can hope to demystify the Sun’s rhythmic pulsations that have both fascinated and perplexed humanity for centuries.
Subject of Research: Solar magnetic activity and dynamics at solar poles
Article Title: Supergranulation and Poleward Migration of the Magnetic Field at High Latitudes of the Sun
News Publication Date: 5-Nov-2025
Web References: DOI Link
References: Not applicable
Image Credits: Not applicable
Keywords
Solar Orbiter, solar magnetic field, supergranulation, solar dynamics, plasma flows, polar regions, solar cycle, astrophysical research, magnetic network, heliophysics, scientific collaboration, solar observations.
