Results 31 to 40 of about 3,012 (284)
TWO REGIMES IN THE REGULARITY OF SUNSPOT NUMBER
The Astrophysical Journal, 2013 Sunspot numbers WN display quasi-periodical variations that undergo regime changes. These irregularities could indicate a chaotic system and be measured by Lyapunov exponents. We define a functional λ (an "irregularity index") that is close to the (maximal) Lyapunov exponent for dynamical systems and well defined for series with a random component ...
Shapoval, A. +3 more
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The Astrophysical Journal, 2023 We report on the annual variation of quiet-time suprathermal ion composition for C through Fe using Advanced Composition Explorer (ACE)/Ultra-Low Energy Isotope Spectrometer data over the energy range 0.3–1.28 MeV nuc ^−1 from 1998 through 2019, covering
B. L. Alterman +4 more
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Quantitative Forecasting of Sunspot Numbers: Statistical Methods and Deep Learning Models [PDF]
EPJ Web of ConferencesForecasting sunspot numbers is fundamental for understanding solar variability and its implications for space weather. However, most existing studies predominantly rely on Total Sunspot Number (TSN), thereby neglecting hemispheric asymmetry and limiting ...
Singha Tiasha +3 more
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Sunspot Number Second Differences as a Precursor of the Following 11-year Sunspot Cycle [PDF]
The Astrophysical Journal, 2017 Abstract Forecasting the strength of the sunspot cycle is highly important for many space weather applications. Our previous studies have shown the importance of sunspot number variability in the declining phase of the current 11-year sunspot cycle to predict the strength of the next cycle when the minimum of the current cycle has been ...
Tatiana Podladchikova +2 more
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Solar Cycle 25 Prediction Using N-BEATS
The Astrophysical Journal, 2023 Solar activities lead to Sun variation with an 11 yr periodicity. The periodic variation affects space weather and heliophysics research. So it is important to accurately predict solar cycle variations. In this paper, we predicted the ongoing Solar Cycle
Xu Su +4 more
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IEEE Access, 2022 Sunspot number is the most basic parameter to describe the level of solar activity. The accurate prediction of sunspot number can reflect the electromagnetic disturbance level of the electromagnetic layer, ionosphere and the middle and high layers in the
Beijia Zhang, Lin Sun, Wenbo Wang
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A Reconstruction of Total Solar Irradiance Based on Wavelet Analysis
Earth and Space Science, 2021 As an important indicator of solar activity, the long‐term total solar irradiance (TSI) observations are needed to uncover the impact of solar activity on Earth's climate.
Haijun Xu, Bin Lei, Zhen Li
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On forecasting the sunspot numbers
Solar Physics, 1990 We have applied a technique recently proposed basing on learning nonlinear dynamics locally to describe the annual sunspot relative numbers. It is proved that the number of past points for prediction should be greater than 4 but less than 10. This rather simple approach yields in average relatively good results for short-term forecasts (< 11 yr ...
J. Kurths, A. A. Ruzmaikin
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Active Days around Solar Minimum and Solar Cycle Parameter
Journal of Astronomy and Space Sciences, 2021 Utilizing a new version of the sunspot number and group sunspot number dataset available since 2015, we have statistically studied the relationship between solar activity parameters describing solar cycles and the slope of the linear relationship ...
Heon-Young Chang
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Journal of Space Weather and Space Climate, 2023 The Madrid Astronomical Observatory implemented a solar observation program from 1876 to 1986. In addition to sunspots, the observers at this observatory recorded other solar features such as prominences.
Aparicio Alejandro Jesús Pérez +3 more
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