Solar Wind Magnetic Fluctuations Diagnosing Local Reconnection Currents*

The 20 years of ACE satellite measurements of B(t) at 1AU enable detailed spectral and dynamical analyses, here supplemented by radial dependencies from Ulysses and Mariner from 0.3 - 5 AU. 1) Variable-duration spectral analyses clearly show that there is no persistent magnetic "spiral" at 1AU, merely the statistical fluctuations of "random walk" dynamics. Similarly, spectral components B(f) above f$\cong $50$\mu $Hz clearly show the $\surd $N scaling of random noise. 2) Pervasive dynamical "arc" events are observed on time-scales 10\textasciicircum 3\textless $\tau $ \textless 10\textasciicircum 5 sec, presumably related to spiky "switchbacks" observed by PSP at 0.1AU. The dynamics appears as B$\theta $-Bz, Br-Bz, and Br-B$\theta $ temporal arcs, with occurrence rates differing by direction. The observed dynamics is closely modelled by finite-duration "pinched" $+$/- current filaments, representing charge non-neutrality of 10\textasciicircum -5 of the e-/p$+$ flux over distances d$\cong $10\textasciicircum 3Mm and times $\tau \cong $2000s. 3) The Br and B$\theta $ (but not Bz) spectral components at the solar rotation frequency f$_{\mathrm{rot}}$ are quite exceptional, varying between 0{\%} and 30{\%} (average 17{\%}) of the total Brms\textasciicircum 2 magnetic energy. In \textit{only} these variable components (with differing radial dependencies) is there a Br-B$\theta $ anti-correlation, which is traditionally mis-interpreted as a persistent spiral. These f$_{\mathrm{rot}}$ components probably reflect z-currents, arising from $\theta $-z-dependent electric potentials from exceedingly small differences in e-/p$+$ ejection from the rotating solar surface.