Results 21 to 30 of about 1,269 (230)
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
openaire +1 more source
Maximum Sunspot Numbers and Active Days [PDF]
Journal of Astronomy and Space Sciences, 2013 Parameters associated with solar minimum have been studied to relate them to solar activity at solar maximum so that one could possibly predict behaviors of an upcoming solar cycle.
Heon-Young Chang
doaj +1 more source
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
doaj +1 more source
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
doaj +1 more source
Prediction of even and odd sunspot cycles
Journal of Space Weather and Space Climate, 2023 Here we study the prediction of even and odd numbered sunspot cycles separately, thereby taking into account the Hale cyclicity of solar magnetism. We first show that the temporal evolution and shape of all sunspot cycles are extremely well-described by ...
Asikainen Timo, Mantere Jani
doaj +1 more source
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
openaire +2 more sources
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
doaj +1 more source
Journal of Space Weather and Space Climate, 2017 We analyze the normalization factors (k′-factors) used to scale secondary observers to the Royal Greenwich Observatory (RGO) reference series of the Hoyt & Schatten (1998a, 1998b) group sunspot number (GSN).
Cliver Edward W.
doaj +1 more source
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
doaj +1 more source
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
doaj +1 more source