Title: Reversals of the solar global magnetic field
Author: V.N.Obridko
Affil: IZMIRAN
Email: solter@izmiran.troitsk.ru
Authors: Shelting B.D.
Affils: IZMIRAN
Abstract: Sign reversal of the global magnetic field of the Sun is an important reference point of the solar cyclicity, because it marks the beginning of a fundamental reconstruction of the heliosphere. However, the solar magnetic fields make different contribution to the formation of the heliospheric field, depending on their characteristic spatial scales. In this work, we analyze the dates of reversal of the polar magnetic field separately for the source-surface (i.e., largest scale) and photospheric fields. The data from three sources are used: WSO data for 1976-2000, Kitt Peak and Mt. Wilson data for 1965-1982, and reconstructed Í-alpha data for 1915-2000. It is shown that, in all cases, the field reversal on the source surface occurs 0.5-1.5 years earlier than in the photosphere. This result may suggest that the large-scale fields are rooted deeper than the photospheric fields.