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A long-term variation is detected in the north-south differences of the solar activity, the phase difference of hemispheric cycles alternates by four Schwabe cycles. This variability is demonstrated by two different methods. It can be the…

Solar and Stellar Astrophysics · Physics 2014-01-10 J. Muraközy , A. Ludmány

We investigate periodicities in mean heliographic latitudes of sunspot groups, called active latitudes, for the last six complete solar cycles (1945-2008). For this purpose, the Multi Taper Method and Morlet Wavelet analysis methods were…

Solar and Stellar Astrophysics · Physics 2023-01-06 A. Kilcik , V. Yurchyshyn , F. Clette , A. Ozguc , J. -P. Rozelot

Solar cycles vary in their amplitude and shape. There are several empirical relations between various parameters linking cycle's shape and amplitude, in particular the Waldmeier relations. As solar cycle is believed to be a result of the…

Solar and Stellar Astrophysics · Physics 2012-05-24 V. V. Pipin , D. D. Sokoloff , I. G. Usoskin

From the previous study (Hiremath 2009b; Hiremath 2010), on the genesis of solar cycle and activity phenomena, it is understood that sunspots are formed at different depths by superposition of Alfven wave perturbations of a strong toroidal…

Solar and Stellar Astrophysics · Physics 2010-12-30 K. M. Hiremath , Lovely , M. R

Solar activity is studied using a cluster analysis of the time-fluctuations of the sunspot number. It is shown that in an Historic period the high activity components of the solar cycles exhibit strong clustering, whereas in a Modern period…

Astrophysics · Physics 2010-11-02 A. Bershadskii

We report a solar jet phenomenon associated with successive flares on November 10th 2014. These explosive events were involved with the satellite spots' emergence around a delta-type sunspot in the decaying active region NOAA 12205. The…

Solar and Stellar Astrophysics · Physics 2017-10-11 Takahito Sakaue , Akiko Tei , Ayumi Asai , Satoru Ueno , Kiyoshi Ichimoto , Kazunari Shibata

The solar activity in Cycle 23--24 shows differences from the previous cycles that were observed with modern instruments, e.g. long cycle duration and a small number of sunspots. To appreciate the anomalies further, we investigated the…

Solar and Stellar Astrophysics · Physics 2015-06-16 Masumi Shimojo

Given a bridgeless graph G, the well-known cycle double cover conjecture posits that there is a list of cycles of G, such that every edge appears in exactly two cycles. In this paper, we prove the cycle double cover conjecture. More…

Combinatorics · Mathematics 2018-11-22 A. Alipour , A. Tayebi

An intriguing possibility is explored that the solar neutrino data could be used as a probe to the magnetic field structure in the sun. Various cyclic phenomena occurring on the surface of the sun have been accounted for by the so-called…

High Energy Physics - Phenomenology · Physics 2007-05-23 Takahiro Kubota , Takeshi Kurimoto , Eiichi Takasugi

Five new correlations between sunspot activity and orbiting position of the Jovian planets are detected. In order to explain these correlations it is suggested that the resonance of the outer planets destabilizes the orbit of Kuiper Belt…

General Physics · Physics 2009-06-25 Jozsef Garai

We present a realistic numerical model of sunspot and active region formation based on the emergence of flux bundles generated in a solar convective dynamo. To this end we use the magnetic and velocity fields in a horizontal layer near the…

Solar and Stellar Astrophysics · Physics 2017-09-20 Feng Chen , Matthias Rempel , Yuhong Fan

The evolution of the photospheric magnetic field during the declining phase and minimum of Cycle 23 and the recent rise of Cycle 24 are compared with the behavior during previous cycles. We used longitudinal full-disk magnetograms from the…

Solar and Stellar Astrophysics · Physics 2012-08-28 Gordon Petrie

Solar eruptive behavior is often modeled with magnetohydrodynamic simulations of magnetic flux emergence. The usual geometry considered is that of a horizontal cylindrical magnetic flux tube. An alternative is the toroidal tube geometry…

Solar and Stellar Astrophysics · Physics 2025-05-16 J. Zhuleku , V. Archontis , K. Moraitis

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

The temporal behaviour of solar active longitudes has been examined by using two sunspot catalogues, the Greenwich Photoheliographic Results (GPR) and the Debrecen Photoheliographic Data (DPD). The time-longitude diagrams of the activity…

Solar and Stellar Astrophysics · Physics 2014-01-09 N. Gyenge , T. Baranyi , A. Ludmány

In this letter we identify similarities amongst sunspots and terrestrial vortices. The dark appearance of the central part of any sunspot is currently justified by an anticipated cooling effect experienced by the ionized gas. However, it…

Solar and Stellar Astrophysics · Physics 2011-10-07 Georgios H. Vatistas

Sunspot groups observed by Royal Greenwich Observatory/US Air Force/NOAA from May 1874 to November 2008 and the Carte Synoptique solar filaments from March 1919 to December 1989 are used to investigate the relative phase shift of the paired…

Solar and Stellar Astrophysics · Physics 2015-05-19 Kejun Li , Hongfei Liang , Wen Feng

We provide a synthesis model demonstrating the "fast dynamo" action of the Sun. The latter is essentially accomplished via two toroidal structures presumably formed in the tachocline and placed symmetrically with respect to the equatorial…

Space Physics · Physics 2017-08-03 D. V. Sarafopoulos

The difference between individual solar cycles in the magnetic butterfly diagram can mostly be ascribed to the stochasticity of the emergence process. We aim to obtain the expectation value of the butterfly diagram from observations of four…

Solar and Stellar Astrophysics · Physics 2024-10-30 Simon Cloutier , Robert H. Cameron , Laurent Gizon

Magnetic field emerges at the surface of the Sun as sunspots and active regions. This process generates a poloidal magnetic field from a rising toroidal flux tube, it is a crucial but poorly understood aspect of the solar dynamo. The…

Solar and Stellar Astrophysics · Physics 2016-07-19 Aaron C. Birch , Hannah Schunker , Douglas C. Braun , Robert Cameron , Laurent Gizon , Björn Löptien , Matthias Rempel