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Related papers: Long-term modulation of solar cycles

200 papers

The duration of activity growths in solar cycles is on average shorter than the duration of its declines. This asymmetry can result from fluctuations in dynamo parameters. A solar dynamo model with fluctuations in the $\alpha$-effect shows…

Solar and Stellar Astrophysics · Physics 2018-11-07 Leonid Kitchatinov , Alexander Nepomnyashchikh

The solar magnetic field, thought to be generated by the motion of plasma within the Sun, alternates on the order of 11-year cycles and is incompletely understood. Industries rely on accurate forecasts of solar activity, but can solar…

Solar and Stellar Astrophysics · Physics 2025-02-20 Floe Foxon

Solar activity in the past millennia can only be reconstructed from cosmogenic radionuclide records in terrestrial archives. However, because of the diversity of the proxy archives, it is difficult to build a homogeneous reconstruction.…

Solar and Stellar Astrophysics · Physics 2018-07-25 Chi Ju Wu , I. G. Usoskin , N. Krivova , G. A. Kovaltsov , M. Baroni , E. Bard , S. K. Solanki

Variations of the sunspot number are important indicators of the solar activity cycles. The sunspot formation is a result of a dynamo process inside the Sun, which is far from being understood. We use simple dynamical models of the dynamo…

Astrophysics · Physics 2009-02-11 I. N. Kitiashvili , A. G. Kosovichev

Relative variations in the number of sunspots and sunspot groups in activity cycles have been analyzed based on data from the Kislovodsk Mountain Astronomical Station and international indices. The following regularities have been…

Solar and Stellar Astrophysics · Physics 2013-09-20 A. G. Tlatov

We investigated the Korean records of naked-eye sunspot observations and found an implication of periodicity of about 200-year. Adding the Chinese records we showed that the historical naked-eye sunspot observations have the similar…

Solar and Stellar Astrophysics · Physics 2019-12-25 Kim Chol-jun , Kim Jik-su

Recently, Rozelot & Eren pointed out that the first solar gravitational moment (J2) might exhibit a temporal variation. The suggested explanation is through the temporal variation of the solar rotation with latitude. This issue is deeper…

Solar and Stellar Astrophysics · Physics 2023-01-19 Saliha Eren , Jean-Pierre Rozelot

The dynamic activity of the Sun -- sustained by a magnetohydrodynamic dynamo mechanism working in its interior -- modulates the electromagnetic, particulate and radiative environment in space. While solar activity variations on short…

Solar and Stellar Astrophysics · Physics 2021-03-31 Dibyendu Nandy

Solar-cycle related variation of differential rotation is investigated through analyzing the rotation rates of magnetic fields, distributed along latitudes and varying with time at the time interval of August 1976 to April 2008. More…

Solar and Stellar Astrophysics · Physics 2015-06-16 K. J. Li , X. J. Shi , J. L. Xie , P. X. Gao , H. F. Liang , L. S. Zhan , W. Feng

Complex network approaches have been recently developed as an alternative framework to study the statistical features of time-series data. We perform a visibility-graph analysis on both the daily and monthly sunspot series. Based on the…

Data Analysis, Statistics and Probability · Physics 2015-06-16 Yong Zou , Michael Small , Zonghua Liu , Jürgen Kurths

The solar cycle and its associated magnetic activity are the main drivers behind changes in the interplanetary environment and the Earth's upper atmosphere (commonly referred to as space weather). These changes have a direct impact on the…

Solar and Stellar Astrophysics · Physics 2013-04-12 Andrés Muñoz-Jaramillo , María Dasi-Espuig , Laura A. Balmaceda , Edward E. DeLuca

We explore the cause of the solar cycle variabilities using a novel 3D Babcock--Leighton dynamo model. In this model, based on the toroidal flux at the base of the convection zone, bipolar magnetic regions (BMRs) are produced with…

Solar and Stellar Astrophysics · Physics 2019-01-30 Bidya Binay Karak , Mark Miesch

The magnetic activity of the Sun, as manifested in the sunspot cycle, originates deep within its convection zone through a dynamo mechanism which involves non-trivial interactions between the plasma and magnetic field in the solar interior.…

Solar and Stellar Astrophysics · Physics 2015-05-13 Dibyendu Nandy

The Sun is a variable star whose magnetic activity varies most perceptibly on a timescale of approximately 11 years. However, significant variation is also observed on much shorter timescales. We observe a quasi-biennial (2 year) signal in…

Temporal variations in the Suns internal velocity field with a periodicity of about 11 years have been observed over the last four decades. The period of these torsional oscillations and their latitudinal propagation roughly coincides with…

Solar and Stellar Astrophysics · Physics 2018-03-22 Sushant S. Mahajan , Dibyendu Nandy , H. M. Antia , B. N. Dwivedi

This study aims to provide further evidence for the potential influence of the global solar magnetic field on localised chromospheric jets, the macrospicules (MS). To find a connection between the long-term variation of properties of MS and…

Solar and Stellar Astrophysics · Physics 2018-05-02 T. S. Kiss , R. Erdelyi

The solar cycle onset at mid-latitudes, the slow down of the sunspot drift toward the equator, the tail-like attachment and the overlap of successive cycles at the time of activity minimum are delicate issues in $\alpha\Omega$ dynamo wave…

Solar and Stellar Astrophysics · Physics 2016-09-07 R. Simoniello , S. C. Tripathy , K. Jain , F. Hill

Using the non-linear mean-field dynamo models we calculate the magnetic cycle parameters, like the dynamo cycle period, the amplitude of the total magnetic energy, and the Poynting flux luminosity from the surface for the solar analogs with…

Solar and Stellar Astrophysics · Physics 2021-01-27 V. V. Pipin

A review of solar cycle prediction methods and their performance is given, including forecasts for cycle 24 and focusing on aspects of the solar cycle prediction problem that have a bearing on dynamo theory. The scope of the review is…

Solar and Stellar Astrophysics · Physics 2015-05-20 K. Petrovay

In the previous study (Hiremath 2006a), the solar cycle is modeled as a forced and damped harmonic oscillator and from all the 22 cycles (1755-1996), long-term amplitudes, frequencies, phases and decay factor are obtained. Using these…

Astrophysics · Physics 2007-05-23 K. M. Hiremath