Facular

The data record, jointly developed by the University of Colorado's Laboratory for Atmospheric and Space Physics (LASP) and the Naval Research Laboratory (NRL), is constructed from solar irradiance models that determine the changes with respect to quiet sun conditions when facular brightening and sunspot darkening features are present on the solar disk where the magnitude of the changes in irradiance are determined from the linear regression of a proxy magnesium (Mg) II index and sunspot area indices against the approximately decade-long solar irradiance measurements of the Solar Radiation and Climate Experiment (SORCE).

As solar activity increases during the 11-yr cycle, the enhanced facular emission more than compensates for the irradiance reduction in sunspots such that the TSI at solar activity maximum exceeds that at solar minimum (Fig.

and the integrated spectral facular and sunspot increments equal their respective contributions to the total solar irradiance:

This agrees with observation: facular emissivity is initially indistinguishable from that of the photosphere at disk center.

In the end, the simplest explanation for the origin for magnetic bright points may be that they are nothing more than facular elements.

The same cannot be said of facular directional spectral emissivity.

In 1961, Rogerson presented an elegant summary of the increase in facular directional emissivity observed near the solar limb [50].

This direct association of sunspot and facular matter has recently been re-emphasized as a result of studying large flares on the solar surface [61].