RELATIONSHIP OF MAGNETIC-FIELD STRENGTH AND BRIGHTNESS OF FINE-STRUCTURE ELEMENTS IN THE SOLAR TEMPERATURE MINIMUM REGION

We have determined a quantitative relationship between magnetic field strength (or magnetic flux) from photospheric magnetograph observations and the brightness temperature of solar fine-structure elements observed at 1600 Å, where the predominant flux source is continuum emission from the solar temperature minimum region. We used a Kitt Peak magnetogram and spectroheliograph observations at 1600 Å taken during a sounding rocket flight of the High Resolution Telescope and Spectrograph from 1987 December 11. We obtained the statistical distributions of brightness temperature in the quiet Sun at 1600 Å, and absolute value of magnetic field strength in the same area, from these observations. Using a technique which obtains the best-fit relationship of a given functional form between these two histogram distributions, we determined a quantitative relationship between absolute value of magnetic field strength B and brightness temperature which is essentially linear from 10 to 150 G. We suggest an interpretation in which a basal heating occurs generally, while brighter elements are produced in magnetic regions with temperature enhancements proportional to B. We examine a mechanism where Alfvén waves produced by solar photospheric granulation motions of velocity v, with an energy flux pv2vA which is linearly proportional to B, are partially dissipated in the temperature minimum region.