Thursday 27 March 2025
Scientists have been studying the sun’s corona, the outer atmosphere of our star, for decades. It’s a challenging task because the corona is incredibly hot, reaching temperatures of millions of degrees Celsius, while the surface of the sun is relatively cool, at around 5,500 degrees Celsius. This temperature difference creates a puzzle that scientists have been trying to solve.
The problem is that the corona should not be as hot as it is. According to our current understanding of physics, the heat generated by the sun’s core should dissipate quickly, making the corona much cooler than it actually is. To explain this discrepancy, scientists have proposed various theories, including the idea that the corona is heated by waves propagating through the sun’s magnetic field.
Now, a team of researchers has taken another step towards solving the coronal heating puzzle. They’ve developed a new model that incorporates two types of waves: Alfvén waves and kink waves. Alfvén waves are generated when the sun’s magnetic field is disturbed, while kink waves occur when twisted magnetic fields vibrate.
The new model, called UAWSOM (Uniturbulent and Alfvén Wave Solar Model), combines these two wave types to create a more comprehensive picture of the corona’s heating. The researchers used computer simulations to test their model against observations of the sun’s behavior.
One key finding is that kink waves are much more effective at heating the corona than previously thought. This is because kink waves can propagate through the entire solar atmosphere, whereas Alfvén waves tend to get trapped near the surface. The researchers found that kink waves can generate significant amounts of heat in the lower corona, which then gets transported upwards by turbulent flows.
The UAWSOM model also predicts that the heating of the corona is not uniform across the sun’s surface. Instead, it varies depending on the strength and orientation of the magnetic fields. This variation could help explain why some regions of the corona are hotter than others.
While this new model doesn’t provide a complete solution to the coronal heating puzzle, it represents an important step forward in our understanding of the sun’s atmosphere. The researchers hope that their findings will help guide future missions and experiments designed to study the corona in greater detail.
The UAWSOM model is also relevant for our understanding of space weather, which can have significant impacts on Earth’s magnetic field and upper atmosphere.
Cite this article: “New Model Sheds Light on Solar Coronas Mysterious Heating”, The Science Archive, 2025.
Sun, Corona, Magnetic Fields, Alfvén Waves, Kink Waves, Turbulence, Solar Atmosphere, Space Weather, Heat, Temperature.
