Simulating activity on the Sun with large plasma models

The main objective of the SunFlare project is modelling and understanding the couplings between the sub-surface layers and visible layers of the Sun: the solar photosphere, chromosphere and corona. – The mass density is much larger in the subsurface layers than in the visible layers. The kinetic and magnetic energy densities are also correspondingly large. The motions that occur in these layers cover a wide scale range. The motions transport heat to the surface of the Sun, allowing the Sun to maintain its enormous energy output. The motions also generate, stretch, and transport magnetic fields to the surface and, as our simulations have shown for the first time, spontaneously create the structure in so-called Solar Active Regions, professor Åke Nordlund from the university of Copenhagen explains. Nordlund heads the team. He is a science coordinator as well as a program developer and works closely with the SunFlare project group. When magnetic fields emerge on the surface of the Sun the energy can be violently released in the form of so-called Solar flares and Coronal Mass Ejections (CMEs). – Solar flares are extremely powerful explosive events, which ultimately may affect the environment in the Earth’s protective magnetosphere. The explosions are often closely accompanied by CMEs, where magnetic energy is converted into intense UV-light emissions, Xrays, gamma rays, as well as highly charged particles. The particles can travel into interplanetary space, resulting in northern lights and magnetic sub-storms in the Earth’s magnetosphere, Nordlund explains.