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arXiv · 1209.6388

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

A. Pietarila·J. Pietarila Graham
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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 $κ$. Failure to exclude network elements previously led to too low estimates of both the cancellation exponent $κ$ and of $<|B_z|>_{\mathrm{true}}$. However, both $κ$ 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 $κ\lessapprox0.38$ and $<|B_z|>_{\mathrm{true}}\lessapprox 270 $gauss can be taken as upper bounds.

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A. Pietarila, J. Pietarila Graham. 2012-09-27. Instrumental and Observational Artifacts in Quiet Sun Magnetic Flux Cance llation Functions. https://doi.org/10.1007/s11207-012-0140-4

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