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Related papers: Long-term changes in solar activity and irradiance

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How has the solar wind evolved to reach what it is today? In this review, I discuss the long-term evolution of the solar wind, including the evolution of observed properties that are intimately linked to the solar wind: rotation, magnetism…

Solar and Stellar Astrophysics · Physics 2021-03-30 A. A. Vidotto

Additional experimental evidence is presented in support of the recent hypothesis that a possible solar influence could explain fluctuations observed in the measured decay rates of some isotopes. These data were obtained during routine…

We study intermittency as a departure from self-similarity of the solar wind magnetic turbulence and investigate the evolution with the heliocentric distance and latitude. We use data from the Ulysses spacecraft measured during two solar…

Space Physics · Physics 2016-08-24 Anna Wawrzaszek , Marius Echim , Wiesław M. Macek , Roberto Bruno

Starting from December 2004, a program for the monitoring of intraday variable sources at a frequency of 5 GHz was performed at the Urumqi Observatory. The analysis of the variability characteristics of the flat-spectrum radio source AO…

Solar and Stellar Astrophysics · Physics 2015-05-27 N. Marchili , T. P. Krichbaum , X. Liu , H. -G. Song , J. M. Anderson , A. Witzel , J. A. Zensus

We use archival daily spot coverage measurements from Howard et al. (1984) to study the rotational modulation of the Sun as though it were a distant star. A quasi-periodic Gaussian process measures the solar rotation period $P_\mathrm{rot}…

Information on the rotation rate of the corona, and its variation over latitude and solar cycle, is valuable for making global connections between the corona and the Sun, for global estimates of reconnection rates, and as a basic parameter…

Solar and Stellar Astrophysics · Physics 2022-04-06 Liam T. Edwards , David Kuridze , Thomas Williams , Huw Morgan

Advances in understanding of the white light faculae measured at the Royal Greenwich Observatory from 1874 to 1976 suggest that they offer a more direct measure of solar brightening by small diameter photospheric magnetic flux tubes than do…

Solar and Stellar Astrophysics · Physics 2015-12-09 Peter Foukal

On 12 March 1996 we obtained observations of the quiet Sun with the SUMER instrument. The observa- tions were sequences of 15-20 second exposures of ultraviolet emission line profiles and of the neighboring continua. These data contain…

Astrophysics · Physics 2009-10-30 Mats Carlsson , Philip G. Judge , Klaus Wilhelm

Global and regional climate model projections are useful for gauging future patterns of climate variables, including solar radiation, but data from these models is often too coarse to assess local impacts. Within the context of solar…

Applications · Statistics 2024-05-21 Maggie Bailey , Doug Nychka , Manajit Sengupta , Jaemo Yang , Soutir Bandyopadhyay

In this paper, I present the results on large-scale evolution of density turbulence of solar wind in the inner heliosphere during 1985 - 2009. At a given distance from the Sun, the density turbulence is maximum around the maximum phase of…

Solar and Stellar Astrophysics · Physics 2011-04-04 P. K. Manoharan

The solar disk is among the brightest gamma-ray sources in the sky. It is also among the most mysterious. No existing model fully explains the luminosity, spectrum, time variability, and morphology of its emission. We perform the first…

High Energy Astrophysical Phenomena · Physics 2020-12-15 Tim Linden , John F. Beacom , Annika H. G. Peter , Benjamin J. Buckman , Bei Zhou , Guanying Zhu

We analyze intermediate degree p-mode eigenfrequencies measured by GONG and MDI/SOHO over a solar cycle to study the source of their variability. We carry out a correlation analysis between the change in frequencies and several measures of…

Solar and Stellar Astrophysics · Physics 2011-02-11 Kiran Jain , S. C. Tripathy , F. Hill

The energy balance for an atmospheric layer near the soil is evaluated. By integrating it over the whole day period a linear relationship between the global daily solar radiation incident on a horizontal surface and the product of the…

Atmospheric and Oceanic Physics · Physics 2014-01-31 Antonio Dumas , Andrea Andrisani , Maurizio Bonnici , Mauro Madonia , Michele Trancossi

There is a pressing need to model X-ray Ultra-Violet (XUV: 1-30 nm) stellar irradiances, given the scarcity of current measurements. One of the measurable effects of a stellar cycle is the significant (more than one order of magnitude)…

Solar and Stellar Astrophysics · Physics 2025-04-14 E. Deliporanidou , G. Del Zanna , T. N. Woods , D. Woodraska

Computed color indices and spectral shapes for individual stars are routinely compared with observations for essentially all spectral types, but absolute fluxes are rarely tested. We can confront observed irradiances with the predictions…

Astrophysics · Physics 2007-09-17 Carlos Allende Prieto

The Sun is an extraordinary workbench, from which several fundamental astronomical parameters can be measured with high precision. Among these parameters, the solar radius $R_{\odot}$ plays an important role in several aspects, such as in…

The Solar Cycle is reviewed. The 11-year cycle of solar activity is characterized by the rise and fall in the numbers and surface area of sunspots. A number of other solar activity indicators also vary in association with the sunspots…

Solar and Stellar Astrophysics · Physics 2015-10-01 David H. Hathaway

The solar activity displays variability and periodic behaviours over a wide range of timescales, with the presence of a most prominent cycle with a mean length of 11 years. Such variability is transported within the heliosphere by solar…

Solar and Stellar Astrophysics · Physics 2022-10-17 R. Reda , L. Giovannelli , T. Alberti

Solar activity is a process driven by many independent but interconnected phenomena. Although the 11-year cycle is the result of operation of the dynamo mechanism, the cause of longer secular variations is not clear. In search of such a…

Solar and Stellar Astrophysics · Physics 2025-11-07 M. M. Katsova , V. N. Obridko , D. D. Sokoloff , N. V. Emelianov

Recently, the study of the influence of solar activity on the Earth's climate received strong attention, mainly due to the possibility, proposed by several authors, that global warming is not anthropogenic, but is due to an increase in…

Atmospheric and Oceanic Physics · Physics 2017-10-11 P. J. D. Mauas , A. P. Buccino , E. Flamenco
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