Evolution of the Sun's large-scale magnetic field since the Maunder minimum

Citation
Sk. Solanki et al., Evolution of the Sun's large-scale magnetic field since the Maunder minimum, NATURE, 408(6811), 2000, pp. 445-447
Citations number
24
Categorie Soggetti
Multidisciplinary,Multidisciplinary,Multidisciplinary
Journal title
NATURE
ISSN journal
00280836 → ACNP
Volume
408
Issue
6811
Year of publication
2000
Pages
445 - 447
Database
ISI
SICI code
0028-0836(20001123)408:6811<445:EOTSLM>2.0.ZU;2-V
Abstract
The most striking feature of the Sun's magnetic field is its cyclic behavio ur. The number of sunspots, which are dark regions of strong magnetic field on the Sun's surface, varies with a period of about 11 years. Superposed o n this cycle are secular changes that occur on timescales of centuries and events like the Maunder minimum in the second half of the seventeenth centu ry, when there were very few sunspots(1,2). A part of the Sun's magnetic fi eld reaches out from the surface into interplanetary space, and it was rece ntly discovered(3) that the average strength of this interplanetary field h as doubled in the past 100 years. There has hitherto been no clear explanat ion for this doubling. Here we present a model describing the long-term evo lution of the Sun's large-scale magnetic field, which reproduces the doubli ng of the interplanetary field. The model indicates that there is a direct connection between the length of the sunspot cycle and the secular variatio ns.