• Surface beneath two sunspots revealed in simulation

    Surface beneath two sunspots revealed in simulation
    Date:26 July 2009 Tags:,

    Shown below is a view of what may be going on below the surface of sunspots, areas on the Sun's surface that are marked by intense magnetic activity. Outward flows from sunspots, such as solar flares and massive ejections of charged plasma, were first discovered 100 years ago. These outward flows can damage satellites and disrupt communications and navigational systems as well as affect weather on Earth.

    The image above is a cross section of the surface below two sunspots. Stronger magnetic field strength is indicated by lighter or brighter colours. This is the first time that scientists have been able to "see" below the visible surface of the Sun to examine underlying physical processes.

    The international team of scientists led by the National Science Foundation (NSF)’s National Centre for Atmospheric Research (NCAR) created the first comprehensive computer model of the sunspots by designing a virtual, 3D simulation of an area on the Sun. The virtual expanse was eight times the length of Earth’s diameter and was as deep as Earth’s radius.

    The scientists simulated sunspot dynamics within the virtual domain using a series of equations solved on NCAR’s new Bluefire Supercomputer, which can perform 76 trillion calculations per second.

    The new models are an improvement over previous ones but they are still not completely accurate. They show the complex structure of sunspots, which consist of horizontal lighter-coloured filaments (penumbra) embedded in a more vertical and darker-coloured central magnetic field (umbra). A further refined model would require more computing power than is currently available.

    For the simulations, the scientists enhanced a model developed at Max Planck Institute for Solar System Research in Germany. The NSF-supported work, will advance research into the Sun and the impact of solar output on Earth’s atmosphere.

    – Irene Chang, NSF

    * In collaboration with the National Science Foundation and Livescience.com

    Related material:
    Video animations
    * Two sunspots simulated in 3D by model data, viewed from above and in cross section below the surface… to watch this animation, click here
    * Close-up in 3D: Transition from inner umbra region to outer penumbra region in one sunspot… to watch this animation, click here

    News story
    * Scientists create first comprehensive computer model of sunspots… more