Scientists have, for the first time, detected giant twisting waves in the lower atmosphere of the Sun, shedding light on the mystery of the Sun’s corona (the region around the Sun, extending more than one million kilometres from its surface) having a vastly higher temperature than its surface. The findings of this investigation, which will help us understand more about the turbulent solar weather and its affect on our planet, are published today in Science.
The massive solar twists, known as Alfvén waves, were discovered in the lower atmosphere with the Swedish Solar Telescope in the Canary Islands by scientists from Queen’s University Belfast, the University of Sheffield and California State University Northridge.
The increase in solar temperature from approximately 6000 degrees on the visible surface of the Sun (photosphere) to well over a million degrees in the higher overlaying solar corona, has remained at the forefront of astrophysical research for over half a century. The new observations reveal the process behind this phenomenon, whereby these unique magnetic oscillations spread upward from the solar surface to the Sun’s corona with an average speed of over 20km per second, carrying enough energy to heat the plasma to well over a few million degrees.
Prof. Mathioudakis, the leader of the Queen’s University Belfast Solar Group, said, “Understanding solar activity and its influence on the Earth’s climate is of paramount importance for human kind. The Sun is not as quiet as many people think. The solar corona, visible from Earth only during a total solar eclipse, is a very dynamic environment which can erupt suddenly, releasing more energy than 10 billion atomic bombs. Our study makes a major advancement in the understanding of how the million-degree corona manages to achieve this feat.”