Does the solar magnetic field increase?

Citation
Va. Kotov et Iv. Kotova, Does the solar magnetic field increase?, ASTRON LETT, 27(4), 2001, pp. 260-266
Citations number
25
Categorie Soggetti
Space Sciences
Journal title
ASTRONOMY LETTERS-A JOURNAL OF ASTRONOMY AND SPACE ASTROPHYSICS
ISSN journal
10637737 → ACNP
Volume
27
Issue
4
Year of publication
2001
Pages
260 - 266
Database
ISI
SICI code
1063-7737(200104)27:4<260:DTSMFI>2.0.ZU;2-L
Abstract
We consider measurements of the general magnetic field (GMF) of the Sun as a star at four world observatories from 1968 until 1999. We show that, with in the error limits, the mean strength of the photospheric magnetic field H (of its longitudinal component, in magnitude) has not changed over the las t 32 years. This is in conflict with the recent conclusion by Lockwood et a l. (1999) that the solar coronal magnetic field increased by 40% from 1964 until 1996 and has almost doubled in the last 100 years. The causes of disc repancies in the results are discussed. At the same time, the GMF exhibits a natural 11-year variation associated with the solar cycle. The strength o f the photospheric longitudinal magnetic field (in absolute value) averaged over 32 years is 0.46 G (at an rms GMF strength of 0.57 G). The mean GMF f or all years of measurements had a south polarity: (H) over bar = -0.030 +/ - 0.018 G. The difference from zero is statistically significant at 1.7 sig ma (90%) and may be directly related to the outstanding problem of the sola r magnetic "monopole." (C) 2001 MAIK "Nauka/Interperiodica".