Instrumental and Observational Artifacts in Quiet Sun Magnetic Flux Cancellation Functions

• Published in: Solar physics Vol. 282; no. 2; pp. 389 - 404
• Main Authors: Pietarila, A., Pietarila Graham, J.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-02-2013
• Subjects: Astrophysics and Astroparticles; Atmospheric Sciences; Physics; Physics and Astronomy; Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics; Solar magnetic fields; Photosphere; Quiet Sun
• ISSN: 0038-0938; 1573-093X
• DOI: 10.1007/s11207-012-0140-4

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
|〉
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 estimates that were too low for both the cancellation exponent
κ
and 〈|
B
z
|〉
true
. However, both
κ
and 〈|
B
z
|〉
true
are overestimated due to noise in magnetograms. While no conclusive value can be derived with data from current instruments, our
Hinode
/SP results of
κ
⪅0.38 and 〈|
B
z
|〉
true
⪅270 gauss can be taken as upper bounds.