Results 231 to 240 of about 22,234 (267)

Statistical analysis and forecasting of solar wind parameters across solar cycles. [PDF]

Sci Rep
He M, Zhu H.
europepmc   +1 more source

A magnetohydrodynamic mechanism for the formation of solar polar vortices. [PDF]

Proc Natl Acad Sci U S A
Dikpati M, Raphaldini B, McIntosh SW, Korsos MB, Guerrero GA, Gilman PA.   +5 more
europepmc   +1 more source

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The Sunspot Number Series

Nature, 1953
SUNSPOT numbers form a quasi-periodic series (see Fig. 1, upper curve) going back for eighteen cycles to 1750. Very numerous attempts have been made to analyse the series, with little success. It does not appear to contain a truly periodic term, as do tides and weather records.
openaire   +3 more sources

Group Sunspot Numbers: Sunspot Cycle Characteristics

Solar Physics, 2002
We examine the "Group" sunspot numbers constructed by Hoyt and Schatten to determine their utility in characterizing the solar activity cycle. We compare smoothed monthly Group Sunspot Numbers to Zurich (International) Sunspot Numbers, 10.7-cm radio flux, and total sunspot area.
David H. Hathaway, Robert M. Wilson, Edwin J. Reichmann   +2 more
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Synchronization of Sunspot Numbers and Sunspot Areas

Solar Physics, 2009
Sunspot activity is usually described by either sunspot numbers or sunspot areas. The smoothed monthly mean sunspot numbers (SNs) and the smoothed monthly mean areas (SAs) in the time interval from November 1874 to September 2007 are used to analyze their phase synchronization.
K. J. Li, P. X. Gao, L. S. Zhan
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Investigation of Sunspot Area Varying with Sunspot Number

Solar Physics, 2016
The statistical relationship between sunspot area (SA) and sunspot number (SN) is investigated through analysis of their daily observation records from May 1874 to April 2015. For a total of 1607 days, representing $3~\%$
K. J. Li, F. Y. Li, J. Zhang, W. Feng
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Relationship between sunspot numbers during years of sunspot maximum and sunspot minimum

Solar Physics, 1980
A correlation analysis shows that the sunspot numbers at the peaks of the last eight solar cycles are well-correlated with the sunspot numbers in heliolatitudes 20°–40° (specially in the southern hemisphere) occurring in the solar minimum years immediately preceding the solar maximum years.
R. P. Kane, N. B. Trivedi
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Prediction of sunspot numbers

Eos, Transactions American Geophysical Union, 1949
A formula for predicting smoothed annual sunspot numbers is developed. A first approximation to the prediction of a future value in a cycle is the mean of all past values for that part of the cycle. This estimate can be improved by adding to the mean a correction proportional to the departure of earlier values of the cycle from the mean cycle.
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The sunspot areas and the relative sunspot numbers

Geofisica pura e applicata, 1960
Within each sunspot cycle the yearly means (A) of the daily sunspot areas increase faster than the corresponding sunspot numbers (R) from the minimum to the maximum of solar activity and then decrease also faster than these numbers till the next minimum.
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Monthly Mean Sunspot Numbers

1985
Daily relative sunspot numbers are based upon counts of spots and group entities of spots on the sun’s surface at some time each day. Wolf devised a relative number with the intent of reducing the spot counts of different observers and telescopes to a common basis.
D. F. Andrews, A. M. Herzberg
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