National Center for Atmospheric Research | University Corporation for Atmospheric Research | 2019 Jan 14
A team of scientists has, for the first time, used a single, cohesive computer model to simulate the entire life cycle of a solar flare: from the buildup of energy thousands of kilometers below the solar surface, to the emergence of tangled magnetic field lines, to the explosive release of energy in a brilliant flash.This visualization is an animation of the solar flare modeled in the new study.
The violet color represent plasma with temperature less than 1 million Kelvin.
Red represents temperatures between 1 million and 10 million Kelvin, and
green represents temperatures above 10 million Kelvin.
(Courtesy Mark Cheung and Matthias Rempel)
The accomplishment, detailed in the journal Nature Astronomy, sets the stage for future solar models to realistically simulate the Sun's own weather as it unfolds in real time, including the appearance of roiling sunspots, which sometimes produce flares and coronal mass ejections. These eruptions can have widespread impacts on Earth, from disrupting power grids and communications networks, to damaging satellites and endangering astronauts.
Scientists at the National Center for Atmospheric Research (NCAR) and the Lockheed Martin Solar and Astrophysics Laboratory led the research. The comprehensive new simulation captures the formation of a solar flare in a more realistic way than previous efforts, and it includes the spectrum of light emissions known to be associated with flares. ...
For the new study, the scientists had to build a solar model that could stretch across multiple regions of the Sun, capturing the complex and unique physical behavior of each one.
The resulting model begins in the upper part of the convection zone — about 10,000 kilometers below the Sun's surface — rises through the solar surface, and pushes out 40,000 kilometers into the solar atmosphere, known as the corona. The differences in gas density, pressure, and other characteristics of the Sun represented across the model are vast.
To successfully simulate a solar flare from emergence to energy release, the scientists needed to add detailed equations to the model that could allow each region to contribute to the solar flare evolution in a realistic way. But they also had to be careful not to make the model so complicated that it would no longer be practical to run with available supercomputing resources. ...
A comprehensive three-dimensional radiative magnetohydrodynamic simulation of a solar flare ~ M. C. M. Cheung et al
- Nature Astronomy (online 26 Nov 2018) DOI: 10.1038/s41550-018-0629-3