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Related papers: Recurrence Quantification Analysis of Two Solar Cy…

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Low-degree solar p-mode observations from the long-lived Birmingham Solar Oscillations Network (BiSON) stretch back further than any other single helioseismic data set. Results from BiSON have suggested that the response of the mode…

Solar and Stellar Astrophysics · Physics 2018-07-18 R. Howe , W. J. Chaplin , G. R. Davies , Y. Elsworth , S. Basu , A. -M. Broomhall

Sunspot number (SSN) is an important - albeit nuanced - parameter that can be used as an indirect measure of solar activity. Predictions of upcoming active intervals, including the peak and timing of solar maximum can have important…

Space Physics · Physics 2023-05-31 Pete Riley

We use Indian temperature data of more than 100 years to study the influence of solar activity on climate. We study the Sun-climate relationship by averaging solar and climate data at various time scales; decadal, solar activity and solar…

Solar and Stellar Astrophysics · Physics 2014-09-09 O. P. M. Aslam , Badruddin

Total and spectral solar irradiance are key parameters in the assessment of solar influence on changes in the Earth's climate. We present a reconstruction of daily solar irradiance obtained using the SATIRE-S model spanning 1974 to 2013…

Solar and Stellar Astrophysics · Physics 2015-07-07 K. L. Yeo , N. A. Krivova , S. K. Solanki , K. H. Glassmeier

The original 110 year long 27-day Recurrence Index (original R27) was published more than forty years ago. That index, based on the autocorrelation of consecutive 27-day sets of the geomagnetic aa-index, is a measure of the cycle-to-cycle…

Solar and Stellar Astrophysics · Physics 2021-01-07 H. H. Sargent

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 have evaluated fluctuations in neutrino fluxes caused by solar gravity (g) modes based on the analysis of linear adiabatic oscillation of a spherically symmetric star. We find that the first-order fluctuation is zero due to geometrical…

Solar and Stellar Astrophysics · Physics 2026-04-09 Yoshiki Hatta , Yuuki Nakano , Sho Sugama , Masanobu Kunitomo , Hiroshi Ito , Takashi Sekii

The sunspot number is analyzed by using detailed sunspot data, including aspects of observability, sunspot sizes, and proper identification of sunspot groups as discrete entities of the solar activity. The tests show that besides the…

Solar and Stellar Astrophysics · Physics 2016-06-01 Judit Muraközy , Tünde Baranyi , András Ludmány

We discuss the difficulties of predicting the solar cycle using mean-field models. Here we argue that these difficulties arise owing to the significant modulation of the solar activity cycle, and that this modulation arises owing to either…

Astrophysics · Physics 2009-06-23 Paul J. Bushby , Steven M. Tobias

We establish that global solar p-mode frequencies can be measured with sufficient precision on time scales as short as nine days to detect activity-related shifts. Using ten years of GONG data, we report that mode-mass and error-weighted…

Astrophysics · Physics 2009-02-10 S. C. Tripathy , F. Hill , K. Jain , J. W. Leibacher

The low solar atmosphere is composed of mostly neutral particles, but the importance of the magnetic field for understanding observed dynamics means that interactions between charged and neutral particles play a very important role in…

Solar and Stellar Astrophysics · Physics 2023-02-16 Andrew Hillier , Ben Snow

Cosmogenic isotopes provide the only quantitative proxy for analyzing the long-term solar variability over a centennial timescale. While essential progress has been achieved in both measurements and modeling of the cosmogenic proxy,…

Solar and Stellar Astrophysics · Physics 2016-03-07 I. G. Usoskin , Y. Gallet , F. Lopes , G. A. Kovaltsov , G. Hulot

Recent models of variations of the Sun's structure with the 11-year activity cycle by Sofia et al (2005) predict strong non-homologous changes of the radius of subsurface layers, due to subsurface magnetic fields and field-modulated…

Astrophysics · Physics 2009-11-13 S. Lefebvre , A. G. Kosovichev , J. P. Rozelot

The ambient solar wind plays a significant role in propagating interplanetary coronal mass ejections and is an important driver of space weather geomagnetic storms. A computationally efficient and widely used method to predict the ambient…

Space Physics · Physics 2023-09-21 Opal Issan , Pete Riley , Enrico Camporeale , Boris Kramer

Three types of observations: the daily values of the solar radio flux at 7 frequencies, the daily international sunspot number and the daily Stanford mean solar magnetic field were processed in order to find all the periodicities hidden in…

Astrophysics · Physics 2009-11-07 S. Zieba , J. Maslowski , A. Michalec , A. Kulak

Debate over the existence of branches in the stellar activity-rotation diagrams continues. Application of modern time series analysis tools to study the mean cycle periods in chromospheric activity index is lacking. We develop such models,…

Solar and Stellar Astrophysics · Physics 2018-11-07 N. Olspert , J. Lehtinen , M. J. Käpylä , J. Pelt , A. Grigorievskiy

The convectively driven, weakly magnetized regions of the solar photosphere dominate the Sun's surface at any given time, but the temporal variations of these quiet regions of the photosphere throughout the solar cycle are still not well…

Solar and Stellar Astrophysics · Physics 2025-05-05 James Crowley , Ivan Milic , Gianna Cauzzi , Kevin Reardon

In order to probe the mechanism of variations of the Solar Constant on the inter-solar-cycle scale, total solar irradiance (TSI, the so-called Solar Constant) in the time interval of 7 November 1978 to 20 September 2010 is decomposed into…

Solar and Stellar Astrophysics · Physics 2015-06-03 K. J. Li , W. Feng , J. C. Xu , P. X. Gao , L. H. Yang , H. F. Liang , L. S. Zhan

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

In addition to the well-known 11-year solar cycle, the Sun's magnetic activity also shows significant variation on shorter time scales, e.g. between one and two years. We observe a quasi-biennial (2-year) signal in the solar p-mode…