THEORETICAL PROPERTIES OF OMEGA-LOOPS IN THE CONVECTIVE ZONE OF THE SUN .2. THE ORIGIN OF ENHANCED SOLAR IRRADIANCE

The brightness of the Sun is observed to vary by 0.2% with the 11 yr activity cycle. We suggest that the brightness increase with magnetic activity is a direct result of the enhanced heat transport provided by the vertical wakes of the successive Omega-loops of magnetic field that produce the activity. The dynamics of a vertical wake in a stratified atmosphere is relatively complicated, but the observed rapid succession of emergence of Omega-loops at a localized site in the middle of a bipolar active region can be understood only if an established concentrated updraft extends up from the bottom of the convective zone. It is these updrafts that we suggest are the major cause of the brightness enhancement. The next paper examines some of the dynamical characteristics of vertical wakes.