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Author Riley, Pete ♦ Lionello, Roberto ♦ Linker, Jon A.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword ASTROPHYSICS, COSMOLOGY AND ASTRONOMY ♦ COMPARATIVE EVALUATIONS ♦ COMPUTERIZED SIMULATION ♦ COSMIC RADIATION ♦ ECLIPSE ♦ HELIOSPHERE ♦ LIMITING VALUES ♦ MAGNETIC FIELDS ♦ MAGNETOHYDRODYNAMICS ♦ PHOTOSPHERE ♦ SOLAR CORONA ♦ SPACE ♦ STAR EVOLUTION ♦ SUN ♦ SUNSPOTS
Abstract Observations of the Sun’s corona during the space era have led to a picture of relatively constant, but cyclically varying solar output and structure. Longer-term, more indirect measurements, such as from {sup 10}Be, coupled by other albeit less reliable contemporaneous reports, however, suggest periods of significant departure from this standard. The Maunder Minimum was one such epoch where: (1) sunspots effectively disappeared for long intervals during a 70 yr period; (2) eclipse observations suggested the distinct lack of a visible K-corona but possible appearance of the F-corona; (3) reports of aurora were notably reduced; and (4) cosmic ray intensities at Earth were inferred to be substantially higher. Using a global thermodynamic MHD model, we have constructed a range of possible coronal configurations for the Maunder Minimum period and compared their predictions with these limited observational constraints. We conclude that the most likely state of the corona during—at least—the later portion of the Maunder Minimum was not merely that of the 2008/2009 solar minimum, as has been suggested recently, but rather a state devoid of any large-scale structure, driven by a photospheric field composed of only ephemeral regions, and likely substantially reduced in strength. Moreover, we suggest that the Sun evolved from a 2008/2009-like configuration at the start of the Maunder Minimum toward an ephemeral-only configuration by the end of it, supporting a prediction that we may be on the cusp of a new grand solar minimum.
ISSN 0004637X
Educational Use Research
Learning Resource Type Article
Publisher Date 2015-04-01
Publisher Place United States
Journal Astrophysical Journal
Volume Number 802
Issue Number 2


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