Secular variations of sunspot magnetic fields: the comparison of various indexes

1Lozitska, NI
1Astronomical Observatory of the Taras Shevchenko National University of Kyiv,Kyiv, Ukraine
Kosm. nauka tehnol. 2010, 16 ;(4):30-36
Publication Language: Russian
It is found that interannual and secular sunspot magnetic field variations really exist and differ strongly from Wolf’s number variations. Trends of magnetic field module Bmax are essentially differ for the results of the Maunt Wilson and Kitt Peak observations made during 1992‒2008. The source of this discrepancy is analyzed. It is shown that the index Bspis practically independent of observation program completeness, instrument quality and astroclimate conditions, and therefore it is suitable for global monitoring of interannual and secular variations of solar magnetic fields. Our study includes data from the Combined database of sunspot magnetic fields at the Pulkovo Observatory, Crimean sunspot magnetic fields archive and data from the synoptic program at the 150-Foot Solar Tower of the Mt. Wilson Observatory. The Mt. Wilson 150-Foot Solar Tower is operated by UCLA, with funding from NASA, ONR and NSF, under agreement with the Mt. Wilson Institute.
Keywords: indexes, sunspots, variations
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