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Related papers: Magnetically Preferred Solar Longitudes: Reality?

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The study of solar active longitudes has generated a great interest in the recent years. In this work we have used an unique continuous sunspot data series obtained from Kodaikanal observatory and revisited the problem. Analysis of the data…

Solar and Stellar Astrophysics · Physics 2017-01-25 Sudip Mandal , Subhamoy Chatterjee , Dipankar Banerjee

Apart from the 11-year solar cycle, another periodicity around 155-160 days was discovered during solar cycle 21 in high energy solar flares, and its presence in sunspot areas and strong magnetic flux has been also reported. This…

Solar and Stellar Astrophysics · Physics 2014-11-20 T. V. Zaqarashvili , M. Carbonell , R. Oliver , J. L. Ballster

The Sun is the main energy source to Earth, and understanding its variability is of direct relevance to climate studies. Measurements of total solar irradiance exist since 1978, but this is too short compared to climate-relevant time…

Solar and Stellar Astrophysics · Physics 2023-10-17 Theodosios Chatzistergos , Natalie A. Krivova , Kok Leng Yeo

Numerical simulations that reproduce solar-like magnetic cycles can be used to generate long-term statistics. The variations in N-S hemispheric cycle synchronicity and amplitude produced in simulations has not been widely compared to…

Solar and Stellar Astrophysics · Physics 2014-11-27 Aimee A. Norton , Paul Charbonneau , Dario Passos

This review provides an introduction to the generation and evolution of the Sun's magnetic field, summarising both observational evidence and theoretical models. The eleven year solar cycle, which is well known from a variety of observed…

Solar and Stellar Astrophysics · Physics 2011-10-17 Alan W. Hood , David W. Hughes

In 1965 Paul D. Jose published his discovery that both the motion of the Sun about the center of mass of the solar system and periods comprised of eight Hale magnetic sunspot cycles with a mean period of ~22.37 years have a matching…

Solar and Stellar Astrophysics · Physics 2017-01-19 Gerald E. Pease , Gregory S. Glenn

Sunspots are dark spots on the solar surface associated with strong magnetic fields. The number, area, and brightness of sunspots are supposed to reflect the intensity of the solar magnetic fields and are often used as proxies for their…

Solar and Stellar Astrophysics · Physics 2015-06-16 K. Georgieva , B. Kirov , Yu. A. Nagovitsyn

The magnetic activity of the Sun becomes stronger and weaker over roughly an 11 year cycle, modulating the radiation and charged particle environment experienced by the Earth as "space weather". Decades of observations from the Mount Wilson…

Solar and Stellar Astrophysics · Physics 2017-08-18 Axel Brandenburg , Savita Mathur , Travis S. Metcalfe

Mutual quasi-periodicities near the solar-rotation period appear in time series based on the Earth's magnetic field, the interplanetary magnetic field, and signed solar-magnetic fields. Dominant among these is one at 27.03 +/- 0.02 days…

Astrophysics · Physics 2009-11-13 J. K. Lawrence , A. C. Cadavid , A. Ruzmaikin

It has recently been claimed that there is significant coherence between the spectral peaks of the global temperature series over the last 160 years and those of the speed of the solar center of mass at periods of 10-10.5, 20-21, 30 and…

Earth and Planetary Astrophysics · Physics 2014-04-24 Sverre Holm

The Sun has a steady 11-year cycle in magnetic activity most well-known by the rising and falling in the occurrence of dark sunspots on the solar disk in visible bandpasses. The 11-year cycle is also manifest in the variations of emission…

Solar and Stellar Astrophysics · Physics 2016-09-19 Ricky Egeland , Willie Soon , Sallie Baliunas , Jeffrey C. Hall , Alexei A. Pevtsov , Gregory W. Henry

The mainstream dynamo models predict that the sunspot cycle is non-stationary and stochastic. The official Solar Cycle Prediction Panel forecasts only the ongoing sunspot cycle because any forecast beyond one cycle is considered impossible.…

Solar and Stellar Astrophysics · Physics 2025-08-14 Lauri Jetsu

Numerous analyses suggest the existence of various quasi-periodicities in solar activity. The power spectrum of solar activity recorded in sunspot data is dominated by the $\sim$11-year quasi-periodicity, known as the Schwabe cycle. In the…

Solar and Stellar Astrophysics · Physics 2020-01-08 P. Frick , D. Sokoloff , R. Stepanov , V. Pipin , I. Usoskin

Although sunspots have been systematically observed on the Sun's surface over the last four centuries, their magnetic properties have been revealed and documented only since the early 1900s. Sunspots typically appear in pairs of opposite…

Solar and Stellar Astrophysics · Physics 2019-09-25 Soumitra Hazra , Dibyendu Nandy

Power spectra of solar activity based on historical records of sunspot numbers and on cosmogenic isotopes show peaks with enhanced power apart from the dominant 11-year solar cycle, such as the 90-year Gleissberg cycle or the 210-year de…

Solar and Stellar Astrophysics · Physics 2019-05-08 Robert Cameron , Manfred Schuessler

The bulk of available stellar activity observations is frequently checked for the manifestation of signs in comparison with the known characteristic of solar magnetic modulation. The problem is that stellar activity records are usually an…

Solar and Stellar Astrophysics · Physics 2020-06-03 R. Stepanov , N. I. Bondar' , M. M. Katsova , D. Sokoloff , P. Frick

The observations of the Sun have been performed over the years, even centuries- Whether are there active longitudes? If yes how stable are they? One of the first The Wilcox Solar Observatory data taken over three cycles N 21, N 22, N 23…

Solar and Stellar Astrophysics · Physics 2018-02-09 E. A. Gavryuseva

This work investigates the solar quasi-periodic cycles with multi-timescales and the possible relationships with planetary motions. The solar cycles are derived from long-term observations of the relative sunspot number and microwave…

Solar and Stellar Astrophysics · Physics 2012-10-16 Baolin Tan , Zhuo Cheng

One obvious feature of the solar cycle is its variation from one cycle to another. In this article, we review the dynamo models for the long-term variations of the solar cycle. By long-term variations, we mean the cycle modulations beyond…

Solar and Stellar Astrophysics · Physics 2023-07-05 Bidya Binay Karak

Recent work has revealed an phenomenological picture of the how the $\sim$11-year sunspot cycle of Sun arises. The production and destruction of sunspots is a consequence of the latitudinal-temporal overlap and interaction of the toroidal…

Solar and Stellar Astrophysics · Physics 2015-06-23 Scott W. McIntosh , Robert J. Leamon