Results 11 to 20 of about 22,234 (267)
Revisiting the Sunspot Number [PDF]
Space Science Reviews, 2014 Our knowledge of the long-term evolution of solar activity and of its primary modulation, the 11-year cycle, largely depends on a single direct observational record: the visual sunspot counts that retrace the last 4 centuries, since the invention of the astronomical telescope.
Frédéric Clette +3 more
exaly +5 more sources
Long-term solar activity explored with wavelet methods [PDF]
Annales Geophysicae, 2006 Long-term solar activity has been studied with a set of wavelet methods. The following indicators of long-term solar activity were used; the group sunspot number, the sunspot number, and the 14C production rate.
H. Lundstedt +3 more
doaj +1 more source
Ratio Mathematica, 2020 The 11 year sunspot number cycle has been a fascinating phenomenon for many scientists in the last three centuries. Various mathematical functions have been used for modelling the 11 year sunspot number cycles.
Amaranathan Sabarinath +2 more
doaj +1 more source
Change of Sunspot Groups Observed from 2002 to 2011 at ButterStar Observatory [PDF]
Journal of Astronomy and Space Sciences, 2012 Since the development of surface magnetic features should reflect the evolution of the solar magnetic field in the deep interior of the Sun, it is crucial to study properties of sunspots and sunspot groups to understand the physical processes working ...
Sung-Jin Oh, Heon-Young Chang
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The Ratio Between the Number of Sunspot and the Number of Sunspot Groups [PDF]
Geomagnetism and Aeronomy, 2017 Data from three solar observatories, Learmonth, Holloman, and San Vito, are used to study the variations in the average number of sunspots per sunspot group. It is found that the different types of sunspot groups and the number of sunspots in these groups have different solar cycle and cycle to cycle variations.
Georgieva, K. +3 more
openaire +2 more sources
The Astrophysical Journal Supplement Series, 2023 In this paper, an optimized long short-term memory model is proposed to deal with the smoothed monthly F _10.7 and nonsmoothed monthly sunspot area (SSA) data, aiming to forecast the peak amplitude of both solar activities and the occurring time for ...
Hongbing Zhu +3 more
doaj +1 more source
Centennial Total Solar Irradiance Variation
Remote Sensing, 2022 Total Solar Irradiance (TSI) quantifies the solar energy received by the Earth and therefore is of direct relevance for a possible solar influence on climate change on Earth.
Steven Dewitte +2 more
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Relative Sunspot Number Observed from 2002 to 2011 at ButterStar Observatory [PDF]
Journal of Astronomy and Space Sciences, 2012 The ButterStar Observatory at the Dongducheon High School has been working for photographic observations of the Sun since October 16, 2002. In this study, we observed the Sun at the ButterStar observatory for 3,364 days from October 16, 2002 to December ...
Sung-Jin Oh, Heon-Young Chang
doaj +1 more source
Relation between Latitude-dependent Sunspot Data and Near-Earth Solar Wind Speed
The Astrophysical Journal, 2023 Solar wind is important for the space environment between the Sun and the Earth and varies with the sunspot cycle, which is influenced by solar internal dynamics.
Qirong Jiao +3 more
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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