Solar Physics

, Volume 239, Issue 1, pp 461–474

On the Near-One-Year Variation of the Sun’s Mean Magnetic Field


    • Science Research InstituteThe Crimean Astrophysical Observatory

DOI: 10.1007/s11207-006-0146-x

Cite this article as:
Kotov, V.A. Sol Phys (2006) 239: 461. doi:10.1007/s11207-006-0146-x


The mean magnetic field (MMF) of the Sun-as-a-star was measured over the last 38 years by six observatories (about 17 000 MMF daily records, 1968 – 2005). The MMF power spectrum reveals the presence of an enigmatic 1.029(7) year periodicity whose origin requires explanation. We show that this quasi-annual variation is not produced by modulation of the MMF signal due to the annual change of the Earth’s helio-latitude (one-year change of visibility of the Sun’s polar regions) as commonly accepted. The nature of this new solar phenomenon is open for discussion.

Download to read the full article text

Copyright information

© Springer Science + Business Media, Inc. 2006