  Line-of-sight magnetograms from the Helioseismic and Magnetic Imager (HMI) of
the Solar Dynamics Observatory (SDO) are analyzed using a diagnostic known as
the "Magnetic Range of Influence," or MRoI. The MRoI is a measure of the length
over which a photospheric magnetogram is balanced and so its application gives
the user a sense of the connective length scales in the outer solar atmosphere.
The MRoI maps and histograms inferred from the SDO/HMI magnetograms primarily
exhibit four scales: a scale of a few megameters that can be associated with
granulation, a scale of a few tens of megameters that can be associated with
super-granulation, a scale of many hundreds to thousands of megameters that can
be associated with coronal holes and active regions, and a hitherto unnoticed
scale that ranges from 100 to 250 megameters. We infer that this final scale is
an imprint of the (rotationally-driven) giant convective scale on photospheric
magnetism. This scale appears in MRoI maps as well-defined, spatially
distributed, concentrations that we have dubbed "g-nodes." Furthermore, using
coronal observations from the Atmospheric Imaging Assembly (AIA) on SDO, we see
that the vicinity of these g-nodes appears to be a preferred location for the
formation of extreme ultraviolet (EUV, and likely X-Ray) brightpoints. These
observations and straightforward diagnostics offer the potential of a
near-real-time mapping of the Sun's largest convective scale, a scale that
possibly reaches to the very bottom of the convective zone.
