Instrumental and Observational Artifacts in Quiet Sun Magnetic Flux Cance llation Functions

Abstract

Under the assumption that the photospheric quiet-Sun magnetic field is turbulent, the cancellation function has previously been used to estimate the true, resolution-independent mean, unsigned vertical flux $<|B_z|{>}_{\mathrm{true}}$. We show that the presence of network elements, noise, and seeing complicate the measurement of accurate cancellation functions and their power-law exponents $\kappa$. Failure to exclude network elements previously led to too low estimates of both the cancellation exponent $\kappa$ and of $<|B_z|{>}_{\mathrm{true}}$. However, both $\kappa$ and $<|B_z|{>}_{\mathrm{true}}$ are over-estimated due to noise in magnetograms. While no conclusive value can be derived with data from current instruments, our {\it Hinode}/SP results of $\kappa ⪅0.38$ and $<|B_z|{>}_{\mathrm{true}}⪅270$gauss can be taken as upper bounds.

Accepted for publication in Solar Physics

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• The Solar Optical Telescope for the Hinode Mission: An Overview
• Turbulent small-scale dynamo action in solar surface simulations
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Cited by in corpus (1)

• Turbulent magnetic energy spectrum and the cancellation function of solar photospheric magnetic fields