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Maunder Minimum forms an archetype for the Grand minima, and detailed knowledge of its temporal development has important consequences for the solar dynamo theory dealing with long-term solar activity evolution. Here we reconsider the…

Solar and Stellar Astrophysics · Physics 2015-05-27 J. M. Vaquero , M. C. Gallego , I. G. Usoskin , G. A. Kovaltsov

On a centennial timescale, solar activity was quantified based on records of instrumental sunspot observations. This article briefly discusses several aspects of the recent archival investigations of historical sunspot records in the 17th…

Solar and Stellar Astrophysics · Physics 2025-02-21 Hisashi Hayakawa

Aims: Although the time of the Maunder minimum (1645--1715) is widely known as a period of extremely low solar activity, claims are still debated that solar activity during that period might still have been moderate, even higher than the…

The Maunder minimum (MM) of greatly reduced solar activity took place in 1645-1715, but the exact level of sunspot activity is uncertain as based, to a large extent, on historical generic statements of the absence of spots on the Sun. Here…

Solar and Stellar Astrophysics · Physics 2015-05-11 J. M. Vaquero , G. A. Kovaltsov , I. G. Usoskin , V. M. S. Carrasco , M. C. Gallego

The recent paucity of sunspots and the delay in the expected start of Solar Cycle 24 have drawn attention to the challenges involved in predicting solar activity. Traditional models of the solar cycle usually require information about the…

Solar and Stellar Astrophysics · Physics 2013-12-05 Mercedes T. Richards , Michael L. Rogers , Donald St. P. Richards

The Maunder Minimum corresponds to a prolonged minimum of solar activity a phenomenon that is of particular interest to many branches of natural and social sciences commonly considered to extend from 1645 until 1715. However, our knowledge…

Solar and Stellar Astrophysics · Physics 2015-06-19 J. M. Vaquero , R. M. Trigo

Using a reconstruction of sunspot numbers stretching over multiple millennia, we analyze the statistics of the occurrence of grand minima and maxima and set new observational constraints on long-term solar and stellar dynamo models. We…

Astrophysics · Physics 2014-11-18 I. G. Usoskin , S. K. Solanki , G. A. Kovaltsov

The Solar Cycle is reviewed. The 11-year cycle of solar activity is characterized by the rise and fall in the numbers and surface area of sunspots. A number of other solar activity indicators also vary in association with the sunspots…

Solar and Stellar Astrophysics · Physics 2015-10-01 David H. Hathaway

Our knowledge of the long-term evolution of solar activity and of its primary modulation, the 11-year cycle, largely depends on a single direct observational record: the visual sunspot counts that retrace the last 4 centuries, since the…

Solar and Stellar Astrophysics · Physics 2023-01-06 Frédéric Clette , Leif Svalgaard , José M. Vaquero , Edward W. Cliver

The Sun exhibits episodic surges of magnetic activity across a range of temporal and spatial scales, the most prominent of which is the 11-ish year modulation of sunspot production. Beside the ~170 (min to max) decadal variation in sunspot…

Solar and Stellar Astrophysics · Physics 2024-08-21 Scott W. McIntosh , Robert J. Leamon

A simple method to detect inconsistencies in low annual sunspot numbers based on the relationship between these values and the annual number of active days is described. The analysis allowed for the detection of problems in the annual…

Solar and Stellar Astrophysics · Physics 2015-06-03 J. M. Vaquero , R. M. Trigo , M. C. Gallego

Sunspot engravings and measurements in 1660-1676 are analyzed to retrieve sunspot area and heliocoordinates. Based on these data, we revise the Hoyt and Schatten (The role of the sun in climate change, 1997) hypothesis of long-lived…

Solar and Stellar Astrophysics · Physics 2025-02-25 Nadezhda Zolotova , Mikhail Vokhmyanin

Solar activity in all its varied manifestations is driven by the magnetic field. Particularly important for many purposes are two global quantities, the Sun's total and open magnetic flux, which can be computed from sunspot number records…

Solar and Stellar Astrophysics · Physics 2021-06-09 N. A. Krivova , S. K. Solanki , B. Hofer , C. -J. Wu , I. G. Usoskin , R. Cameron

Sunspots are a canonical marker of the Sun's internal magnetic field which flips polarity every ~22-years. The principal variation of sunspots, an ~11-year variation in number, modulates the amount of magnetic field that pierces the solar…

Detailed models of the solar cycle require information about the starting time and rise time as well as the shape and amplitude of the cycle. However, none of these models includes a discussion of the variations in the length of the cycle,…

Astrophysics · Physics 2007-05-23 Michael L. Rogers , Mercedes T. Richards , Donald St. P. Richards

One of the most striking aspects of the 11-year sunspot cycle is that there have been times in the past when some cycles went missing, a most well-known example of this being the Maunder minimum during 1645-1715. Analyses of cosmogenic…

Solar and Stellar Astrophysics · Physics 2014-04-09 Arnab Rai Choudhuri , Bidya Binay Karak

The Maunder Minimum (1645-1715 approximately) was a period of very low solar activity and a strong hemispheric asymmetry, with most of sunspots in the southern hemisphere. In this paper, two data sets of sunspot latitudes during the Maunder…

Solar and Stellar Astrophysics · Physics 2015-01-27 J. M. Vaquero , J. M. Nogales , F. Sánchez-Bajo

The planetary hypothesis of the solar cycle is an old idea in which the gravitational influence of the planets has a non-negligible effect on the causes of the solar magnetic cycle. In this work we looked for a possible causal link in…

Earth and Planetary Astrophysics · Physics 2012-07-24 Rodolfo Gustavo Cionco , Rosa Hilda Compagnucci

The grand minimum in the Sun's activity is a distinctive mode characterized by a magnetic lull that almost completely lacks the emergence of sunspots on the solar surface for an extended duration. The factors driving this transition of an…

Solar and Stellar Astrophysics · Physics 2024-12-25 Chitradeep Saha , Dibyendu Nandy

Aims. The Sun shows strong variability in its magnetic activity, from Grand minima to Grand maxima, but the nature of the variability is not fully understood, mostly because of the insufficient length of the directly observed solar activity…

Solar and Stellar Astrophysics · Physics 2014-02-24 I. G. Usoskin , G. Hulot , Y. Gallet , R. Roth , A. Licht , F. Joos , G. A. Kovaltsov , E. Thebault , A. Khokhlov
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