What Lies Beneath A Sunspot
. The temperature and flow structure under a sunspot have
been probed using local helioseismology techniques with data obtained by the
Michelson Doppler Imager instrument aboard the SOlar and Heliospheric Observatory, or SOHO for short. The intense magnetic fields in and below a sunspot
act as a plug that prevents the up-flow of energy from the hot solar interior.
As a result, the sunspot is cooler and darker than its surroundings (dark blue region in the bottom cross section).
Heat builds up below the magnetic plug, so the material underneath the
sunspotís magnetic fields becomes hotter (red
area in cross section). The converging flows of surrounding cooler
material, denoted by the arrows, help hold a sunspot together. (Courtesy of
the SOHO MDI consortium. SOHO is a project of international
cooperation between ESA and NASA.)
Copyright 2010, Professor Kenneth R. Lang, Tufts University