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Related papers: Solar total irradiance in cycle 23

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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 solar minimum 23/24 is considered to be unusual because it exhibits features that differ notably from those commonly seen in pervious minima. In this letter, we analyze the solar polar magnetic field, the potential-field solution of the…

Solar and Stellar Astrophysics · Physics 2024-07-10 Huichao Li , Xueshang Feng , Fengsi Wei

We could infer a secular decreasing trend in the poloidal to toroidal solar magnetic flux amplification factor ( Af) using geomagnetic observations ( classic and IHV corrected aa indices) during the sunspot cycles 9-23. A similar decreasing…

General Physics · Physics 2010-12-23 T. E. Girish , G. Gopkumar

The solar dynamo is essentially a cyclic process in which the toroidal component of the magnetic field is converted into the poloidal one and vice versa. This cyclic loop is disturbed by some nonlinear and stochastic processes mainly…

Solar and Stellar Astrophysics · Physics 2024-03-12 Aparup Ghosh , Pawan Kumar , Amrita Prasad , Bidya Binay Karak

The polar field reversal is a crucial process in the cyclic evolution of the large-scale magnetic field of the Sun.Various important characteristics of a solar cycle, such as its duration and strength, and also the cycle predictability, are…

Solar and Stellar Astrophysics · Physics 2023-08-02 Elena M. Golubeva , Akash Biswas , Anna I. Khlystova , Pawan Kumar , Bidya Binay Karak

Context. Solar spectral irradiance (SSI) variability is one of the key inputs to models of the Earth's climate. Understanding solar irradiance fluctuations also helps to place the Sun among other stars in terms of their brightness…

Solar and Stellar Astrophysics · Physics 2019-11-20 R. V. Tagirov , A. I. Shapiro , N. A. Krivova , Y. C. Unruh , K. L. Yeo , S. K. Solanki

We are reaching the point where spectropolarimetric surveys have run for long enough to reveal solar-like magnetic activity cycles. In this paper we investigate what would be the best strategy to identify solar-like magnetic cycles and ask…

Solar and Stellar Astrophysics · Physics 2020-11-04 Lisa T. Lehmann , Gaitee A. J. Hussain , Aline A. Vidotto , Moira M. Jardine , Duncan H. Mackay

We present the initial results of an observational study into the variation of the dominant length-scale of quiet solar emission: supergranulation. This length-scale reflects the radiative energy in the plasma of the upper solar…

Solar and Stellar Astrophysics · Physics 2015-05-27 Scott W. McIntosh , Robert J. Leamon , Rachel A. Hock , Mark P. Rast , Roger K. Ulrich

We study the asymmetric distribution of weak photospheric magnetic field values in the two hemispheres separately using synoptic maps from SDO/HMI, SOLIS/VSM and WSO during solar cycles 21-24. We calculate the weak-field asymmetry (shift)…

Solar and Stellar Astrophysics · Physics 2019-10-09 Tibebu Getachew , Ilpo Virtanen , Kalevi Mursula

We inspect the evolution of SIRs from Earth to Mars (distance range 1-1.5 AU) over the declining phase of solar cycle 24 (2014-2018). So far, studies only analyzed SIRs measured at Earth and Mars at different times. We compare existing…

Earth and Planetary Astrophysics · Physics 2021-05-19 Paul Geyer , Manuela Temmer , Jingnan Guo , Stephan G. Heinemann

The dynamics of the solar radiative interior are still poorly constrained by comparison to the convective zone. This disparity is even more marked when we attempt to derive meaningful temporal variations. Many data sets contain a small…

Solar and Stellar Astrophysics · Physics 2015-06-05 Antonio Eff-Darwich , Sylain G. Korzennik

We analyze and model total solar irradiance variability on time scales from minutes to months, excluding variations due to p-mode oscillations, using a combination of convective and magnetic components. These include granulation, the…

Solar and Stellar Astrophysics · Physics 2013-03-11 Andrey D. Seleznyov , Sami K. Solanki , Natalie A. Krivova

The solar magnetic activity cycle is responsible for periodic episodes of severe space weather, which can perturb satellite orbits, interfere with communications systems, and bring down power grids. Much progress has recently been made in…

Astrophysics · Physics 2007-05-23 T. S. Metcalfe , T. J. Henry , M. Knolker , D. R. Soderblom

Evidence strongly indicates that the strength of the Sun's polar fields near the time of a sunspot cycle minimum determines the strength of the following solar activity cycle. We use our Advective Flux Transport (AFT) code, with flows well…

Solar and Stellar Astrophysics · Physics 2017-02-01 David H. Hathaway , Lisa A. Upton

We have used solar oscillation frequencies and frequency splittings obtained over solar cycles 23, 24 and the rising phase of solar cycle 25 to investigate whether the tachocline properties (jump i.e., the change in the rotation rate across…

Solar and Stellar Astrophysics · Physics 2024-10-04 Sarbani Basu , Wesley Antônio Machado Andrade de Aguiar , Sylvain G. Korzennik

We study, by using a wavelet decomposition methodology, the solar signature on global surface temperature data using the ACRIM total solar irradiance satellite composite by Willson and Mordvinov. These data present a +0.047%/decade trend…

Geophysics · Physics 2010-05-31 Nicola Scafetta , Bruce J. West

We propose a novel approach to reconstruct the surface magnetic helicity density on the Sun or sun-like stars. The magnetic vector potential is determined via decomposition of vector magnetic field measurements into toroidal and poloidal…

Solar and Stellar Astrophysics · Physics 2019-06-12 Valery V. Pipin , Alexei A. Pevtsov , Yang Liu , Alexander G. Kosovichev

Although systematic measurements of the solar polar magnetic field exist only from mid 1970s, other proxies can be used to infer the polar field at earlier times. The observational data indicate a strong correlation between the polar field…

Astrophysics · Physics 2009-11-13 Jie Jiang , Piyali Chatterjee , Arnab Rai Choudhuri

Using the polar vector magnetic field data observed by Hinode from 2012 to 2021, we study the long-term variations of the magnetic flux, the flux proportion of different polarities, and the magnetic inclination with respect to the local…

Solar and Stellar Astrophysics · Physics 2025-09-25 Shuhong Yang , Chunlan Jin , Qiao Song , Yuzong Zhang , Yin Li , Yijun Hou , Ting Li , Guiping Zhou , Yuanyong Deng , Jingxiu Wang

The Sun's polar magnetic fields are directly related to solar cycle variability. The strength of the polar fields at the start (minimum) of a cycle determine the subsequent amplitude of that cycle. In addition, the polar field reversals at…

Solar and Stellar Astrophysics · Physics 2014-08-01 Lisa Upton , David H. Hathaway
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