A 10.7 cm solar flux measurement is a determination of the strength of solar radio emission in a 100 MHz‐wide band centered on 2800 MHz (a wavelength of 10.7 cm), averaged over an hour. It is expressed in solar flux units (sfu), where 1 sfu = 10−22 W m−2 Hz−1.
It comprises a time‐varying mix of up to three principal emission mechanisms which may be differently distributed over the solar disk and may vary independently with time. It contains thermal free‐free emission from the chromosphere and corona, and from concentrations of plasma supported in the chromosphere and corona by active region magnetic fields.
