An international research team using NASA's Parker Solar Probe has discovered that the magnetic fields threading the turbulent solar wind reverse their direction of rotation at extremely small scales, a phenomenon never directly observed before. The finding reveals a hidden order within space plasma turbulence and could help scientists better understand the solar wind and improve models used to forecast geomagnetic storms.
The team, which included researchers from the Technische Universität Braunschweig, the University of Tokyo, Tohoku University, Kyushu University and Osaka University, brought together scientists from ten countries and analyzed highly precise measurements of magnetic fields and particles taken by the Parker Solar Probe. They found that at larger scales the magnetic fields tend to rotate counterclockwise when viewed outward from the Sun, but at shorter wavelengths the preferred rotation flips to clockwise.
Turbulence in space is fundamentally different from turbulence on Earth. Much of the matter in space consists of electrically charged particles in a plasma state, where particles interact with magnetic and electric fields and rarely collide. This makes its behavior difficult to understand, but the new discovery reveals a clear pattern within the chaos.
The magnetic reversal occurs at a critical boundary where the plasma stops behaving collectively like a fluid and begins to exhibit dynamics governed by individual particles. The reversal becomes more pronounced and shifts toward longer wavelengths as the solar wind travels farther from the Sun.
"We see a clear structure in the spectrum, even though the turbulence represents unstructured motions," said Dr. Masatomi Iizawa (TU Braunschweig), the study's first author. Dr. Yokoi (University of Tokyo) emphasized the broader importance: "The results are of great significance for both plasma physics and astrophysics."
Plasma turbulence is a major feature of many cosmic environments, including Earth's magnetosphere, the solar wind, and accretion disks around astronomical objects. It also influences the shock waves and magnetic clouds that travel from the Sun, and these disturbances can play an important role in geomagnetic storms. The new insight into how organized patterns emerge from turbulence could improve the physical models used to forecast geomagnetic storms.
Analysis
Why This Matters
- Reveals an orderly signature in the seemingly random turbulence of space plasma, giving scientists a new tool to understand how energy is transferred across scales.
- Improved understanding of plasma turbulence can lead to better forecasts of solar storms and geomagnetic disturbances, protecting satellites, power grids, and astronauts.
- Marks a significant advance in the fundamental physics of plasma and astrophysical turbulence, relevant to many environments from stars to accretion disks.
Background
The solar wind is a continuous stream of charged particles flowing from the Sun. NASA's Parker Solar Probe, launched in 2018, flies closer to the Sun than any previous spacecraft, measuring magnetic fields and particles in the Sun's outer atmosphere and solar wind. Turbulence in the solar wind has long been studied, but its behavior at the scales where plasma transitions from fluid to particle dynamics has been poorly understood. The new observation provides the first direct evidence of a magnetic reversal at these scales.
What to Watch
- Future passes of Parker Solar Probe as it approaches even closer to the Sun, which may reveal how the reversal evolves nearer the source of the solar wind.
- Integration of the magnetic reversal signature into computer models of space weather, potentially improving the accuracy of geomagnetic storm forecasts.
- Complementary observations from the European Space Agency's Solar Orbiter, which may help confirm the phenomenon and explore its dependence on solar distance.
Checked
12 claims in this story checked against 1 source: 12 supported.
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- SupportedParker Solar Probe observations revealed a hidden magnetic reversal in solar-wind turbulence.Latest Science News -- ScienceDaily: “By analyzing highly precise measurements of magnetic fields and particles, the team discovered that turbulent magnetic fields reverse their direction of rotation at a particular range of wavelengths.”
- SupportedThe finding reveals an orderly pattern in chaotic plasma and has implications for space-weather forecasting.Latest Science News -- ScienceDaily: “The discovery, published in The Astrophysical Journal Letters , reveals a previously unobserved phenomenon that could improve our understanding of the solar wind and the turbulent conditions that influence space weather.”
- SupportedThe reversal occurs at very small scales and was directly observed for the first time.Latest Science News -- ScienceDaily: “This marks the first direct observation of such a reversal in space turbulence.”
- SupportedThe discovery could help scientists understand the solar wind and improve models for forecasting geomagnetic storms.Latest Science News -- ScienceDaily: “The findings could ultimately help scientists better understand the complex processes that govern the solar wind and improve the physical models used to forecast geomagnetic storms.”
- SupportedThe research team included the five named universities and brought together scientists from ten countries.Latest Science News -- ScienceDaily: “The collaboration brought together scientists from ten countries, including researchers at the Institute of Theoretical Physics at Technische Universität Braunschweig.”
- SupportedAt larger scales the magnetic fields tend to rotate counterclockwise when viewed outward from the Sun, while at much smaller scales the preferred rotation switches to clockwise.Latest Science News -- ScienceDaily: “When viewed along a direction pointing outward from the Sun, magnetic fields at larger scales tend to rotate counterclockwise. At much smaller scales, however, the preferred rotation switches to clockwise.”
- SupportedThe reversal occurs at a boundary where plasma shifts from fluid-like collective behavior to behavior governed by individual particles.Latest Science News -- ScienceDaily: “This reversal occurs precisely where plasma stops behaving primarily like a fluid and begins exhibiting behavior governed by individual particles.”
- SupportedThe reversal becomes more pronounced and shifts toward longer wavelengths as the solar wind travels farther from the Sun.Latest Science News -- ScienceDaily: “Even more surprisingly, the reversal becomes more pronounced and shifts toward longer wavelengths as the solar wind travels farther from the Sun.”
- SupportedDr. Masatomi Iizawa said, “We see a clear structure in the spectrum, even though the turbulence represents unstructured motions,” and is the study’s first author.Latest Science News -- ScienceDaily: “"We see a clear structure in the spectrum, even though the turbulence represents unstructured motions," says Dr. Masatomi Iizawa (TU Braunschweig), the study's first author.”
- SupportedDr. Yokoi said, “The results are of great significance for both plasma physics and astrophysics.”Latest Science News -- ScienceDaily: “Dr. Yokoi (University. of Tokyo) emphasizes the broader importance of the discovery, stating, "The results are of great significance for both plasma physics and astrophysics."”
- SupportedPlasma turbulence is a major feature of environments including Earth’s magnetosphere, the solar wind and accretion disks.Latest Science News -- ScienceDaily: “Plasma turbulence is a major feature of many environments throughout the universe, including Earth's magnetosphere, the solar wind, regions affected by solar eruptions, interplanetary space, and the disks of material surrounding astronomical objects known as accretion disks.”
- SupportedPlasma turbulence influences shock waves and magnetic clouds that travel from the Sun, and these disturbances can play an important role in geomagnetic storms.Latest Science News -- ScienceDaily: “It also influences the shock waves and clouds of magnetic material that travel through interplanetary space following eruptions on the Sun. These disturbances can play an important role in geomagnetic storms”