For more than 60 years, observations of the sun have shown that when magnetic waves leave the sun’s interior, the intensity increases, but its underlying causes remain unsolved. Now an international team of researchers has finally solved the mystery: A significant change in temperature between the sun’s surface and the outer corona creates boundaries that are reflective, capture waves and significantly enhance them, Science reported Tuesday. This latest study may help reveal why the corona is warmer than the sun’s surface.
Scientists have long believed that magnetic waves are “porters” who transport energy from the huge energy reservoirs inside the sun (generated by nuclear fusion) to the outer regions of their atmosphere, so it is important to understand how magnetic waves are produced and travel within the sun.
In the latest study, a team of 13 scientists from five countries, the Low-Level Solar Atmospheric Waves (WaLSA), used high-resolution observations from the Dunn Sun Telescope in New Mexico to study solar magnetic waves.
Study leader David Jess, of Queen’s University’s School of Mathematics and Physics in the UK, explained: “By breaking down sunlight into basic colors, we can examine the behavior of certain elements in the sun’s atmosphere, including silicon (formed near the sun’s surface), calcium and helium (formed in the sun’s chromasphere, where waves are most visible). Changes in elements reveal the velocity of the solar plasma, and the timing of the solar plasma’s evolution can be used as a benchmark, allowing us to record the frequency of solar fluctuations. ”
They then used supercomputers to simulate the data and found that the growth process of solar magnetic waves could be attributed to the formation of boundaries similar to those of “acoustic resonators”: significant changes in temperature between the sun’s surface and the outer corona, creating boundaries that are reflective, capture waves and make waves significantly stronger. Moreover, the thickness of the “resonant cavity” (the distance between significant temperature changes) has an important effect on the volatility characteristics.
Dr Jess explained: “Our new understanding of the motion of solar magnetic waves may help scientists uncover the mystery of why the outer corona of the sun, farther away from the heat source, is hotter than the sun’s surface. Generally speaking, the closer we get to the heat source, the warmer we feel. However, the sun’s outer layer is hotter than the sun’s surface. “