Seething Horizontal Magnetic Fields in the Quiet Solar Photosphere

The photospheric magnetic field outside of active regions and the network has a ubiquitous and dynamic line-of-sight component that strengthens from disk center to limb as expected for a nearly horizontal orientation. This component shows a striking time variation with an average temporal rms near the limb of 1.7 G at ~3'' resolution. In our moderate-resolution observations the nearly horizontal component has a frequency variation power-law exponent of -1.4 below 1.5 mHz and is spatially patchy on scales up to ~15''. The field may be a manifestation of changing magnetic connections between eruptions and evolution of small magnetic flux elements in response to convective motions. It shows no detectable latitude or longitude variations.