A. López Ariste, A. Sainz Dalda
Context: The presence of a turbulent magnetic field in the quiet Sun has been
unveiled observationally using di?erent techniques. The magnetic field is
quasi-isotropic and has field strengths weaker than 100G. It is pervasive and
may host a local dynamo. Aims: We aim to determine the length scale of the
turbulent magnetic field in the quiet Sun. Methods: The Stokes V area asymmetry
is sensitive to minute variations in the magnetic topology along the line of
sight. Using data provided by Hinode-SOT/SP instrument, we performed a
statistical study of this quantity.We classified the di?erent magnetic regimes
and infer properties of the turbulent magnetic regime. In particular we
measured the correlation length associated to these fields for the first time.
Results: The histograms of Stokes V area asymmetries reveal three di?erent
regimes: one organized, quasi-vertical and strong field (flux tubes or other
structures of the like); a strongly asymmetric group of profiles found around
field concentrations; and a turbulent isotropic field. For the last, we confirm
its isotropy and measure correlation lengths from hundreds of kilometers down
to 10km, at which point we lost sensitivity. A crude attempt to measure the
power spectra of these turbulent fields is made. Conclusions: In addition to
confirming the existence of a turbulent field in the quiet Sun, we give further
prove of its isotropy.We also measure correlation lengths down to 10km. The
combined results show magnetic fields with a large span of length scales, as
expected from a turbulent cascade.
View original:
http://arxiv.org/abs/1202.5436
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