![]() ![]() As long as the in-situ data and remote sensing data is concurrent, Daniele can perform the correlation. It could be another spacecraft, such as Parker Solar Probe. This is exactly the kind of linkage science that Solar Orbiter was designed to do, but it does not necessarily mean that Solar Orbiter needs to fly through the switchback. In other words, to have a spacecraft fly through the magnetic reversal and be able to see what’s happened on the solar surface. “The next step is to try to statistically link switchbacks observed in situ with their source regions on the Sun,” says Daniele. This is because when spacecraft fly through switchbacks, they often register a localised acceleration of the solar wind. In understanding switchbacks, solar physicists may also be taking a step toward understanding the details of how the solar wind is accelerated and heated away from the Sun. The results proved to be absolutely spectacular!” Of course, the first image was just a snapshot and we had to temper our enthusiasm until we had used the excellent Metis coverage to extract temporal information and do a more detailed spectral analysis of the images themselves. Rather like cracking a whip, this releases energy and sets an S-shaped disturbance traveling off into space, which a passing spacecraft would record as a switchback.Īccording to Gary Zank, who proposed one of the theories for the origin of switchbacks, “The first image from Metis that Daniele showed suggested to me almost immediately the cartoons that we had drawn in developing the mathematical model for a switchback. As the field lines crowd together, they can reconnect into more stable configurations. They are magnetic highways along which the plasma can flow freely, and give rise to the fast solar wind.ĭaniele and Gary proved that switchbacks occur when there is an interaction between a region of open field lines and a region of closed field lines. Open field lines are the reverse, they emanate from the Sun and connect with the interplanetary magnetic field of the Solar System. Very little plasma can escape into space above these field lines and so the speed of the solar wind tends to be slow here. The closed lines are loops of magnetism that arch up into the solar atmosphere before curving round and disappearing back into the Sun. The theory looked at the way different magnetic regions near the surface of the Sun interact with each other.Ĭlose to the Sun, and especially above active regions, there are open and closed magnetic field lines. Gary Zank, University of Alabama in Huntsville, USA. Further analysis of the Metis data showed that the speed of the plasma above this region was very slow, as would be expected from an active region that has yet to release its stored energy.ĭaniele instantly thought this resembled a generating mechanism for the switchbacks proposed by Prof. Active regions are associated with sunspots and magnetic activity. To Daniele Telloni, National Institute for Astrophysics - Astrophysical Observatory of Torino, Italy, it looked suspiciously like a solar switchback.Ĭomparing the Metis image, which had been taken in visible light, with a concurrent image taken by Solar Orbiter’s Extreme Ultraviolet Imager (EUI) instrument, he saw that the candidate switchback was taking place above an active region catalogued as AR 12972. At around 20:39 UT, Metis recorded an image of the solar corona that showed a distorted S-shaped kink in the coronal plasma. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |