The following movie shows electron number density perturbation throughout a simulation of the Thermal Farley-Buneman Instability (TFBI) from my recent work (Evans+ 2023). Note that the color scale changes over time.

The simulation starts with a small random perturbation, smoothed over a few grid cells to avoid any numerical issues with grid-scale fluctuations. A wave-like structure develops, and the TFBI causes the perturbation amplitude to grow over time, which can be seen by the changing color bar. Eventually, the perturbation grows large enough that the linear TFBI is no longer the dominant effect, and turbulence develops. This turbulence causes heating (not immediately apparent from this movie; see the paper for more details).

There are currently unknown sources of heating just above the Sun’s surface, in a region known as the chromosphere. We predict the TFBI occurs throughout the chromosphere and, as shown by simulations, causes heating. We need to study the TFBI more, to determine whether this heating is enough to account for the heating that’s missing from the most up-to-date models of the Sun’s chromosphere.

(This page was last updated on September 9, 2023)