Results 21 to 30 of about 3,105 (240)
Heartbeat of the sun from principal component analysis and prediction of solar activity on a millenium timescale [PDF]
, 2015 We derive two principal components (PCs) of temporal magnetic field variations over the solar cycles 21-24 from full disk magnetograms covering about 39% of data variance, with σ = 0.67. These PCs are attributed to two main magnetic waves travelling from
Shepherd, Simon J. +10 more
core +1 more source
Legal restrictions, “sunspots,” and cycles [PDF]
Journal of Economic Theory, 1989 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
openaire +3 more sources
A Representation of the Sunspot Cycle* [PDF]
Bell System Technical Journal, 1939 ALTHOUGH sunspots had been observed occasionally back to ancient times, their study may be said to date from their rediscovery by Galileo in the spring of 1610 with the then newly invented telescope. Since then much has been written about their nature, their periodicities and possible influence on human affairs.
openaire +3 more sources
Re-examining sunspot tilt angle to include anti-Hale statistics [PDF]
, 2014 Sunspot groups and bipolar magnetic regions (BMRs) serve as an observational diagnostic of the solar cycle. We use Debrecen Photohelographic Data (DPD) from 1974-2014 that determined sunspot tilt angles from daily white light observations, and data ...
Li, J., McClintock, B. H., Norton, A. A.
core +1 more source
Prediction of solar activity on the basis of spectral characteristics of sunspot number [PDF]
Annales Geophysicae, 2004 Prediction of solar activity strength for solar cycles 23 and 24 is performed on the basis of extrapolation of sunspot number spectral components. Sunspot number data during 1933-1996 periods (solar cycles 17-22) are searched for periodicities by ...
E. Echer +4 more
doaj +1 more source
Timing terminators : forecasting sunspot cycle 25 onset [PDF]
, 2020 Recent research has demonstrated the existence of a new type of solar event, the “terminator.” Unlike the Sun’s signature events, flares and coronal mass ejections, the terminator most likely originates in the solar interior, at or near the tachocline ...
McIntosh, Scott W. +3 more
core +1 more source
Differential Rotation for Different-sized Sunspot Groups Early Observed by the OGAUC
The Astrophysical Journal, 2023 Solar differential rotation is an important ingredient of the solar dynamo model, not only because the solar rotation profile is one of the key inputs in a solar dynamo model, but also because it imposes constraints for the solar dynamo model.
Miao Wan +3 more
doaj +1 more source
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
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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Sunspot numbers: Implications on Eastern African rainfall
South African Journal of Science, 2014 Following NASA’s prediction of sunspot numbers for the current sunspot cycle, Cycle 24, we now include sunspot numbers as an explanatory variable in a statistical model. This model is based on fitting monthly rainfall values with factors and covariates
Francis Gachari +2 more
doaj +1 more source