ARLA/CLUSTER: Recente estudo cientifico indica que o Ciclo Solar 25 pode estar entre os mais fortes de todos

[João Costa > CT1FBF]

Sunspot Cycle 25 could be among the strongest ever

The ARRL reports a research paper has concluded that Solar Cycle 25 will
stronger than the just-ended Solar Cycle 24 and likely stronger than Solar
Cycle 23

The League says:

A research paper, "Overlapping Magnetic Activity Cycles and the Sunspot
Number: Forecasting Sunspot Cycle 25 Amplitude," by Scott W. McIntosh,
Deputy Director of the National Center for Atmospheric Research in Boulder,
et al., has concluded that Solar Cycle 25 could be among the strongest
sunspot cycles ever observed, and will almost certainly be stronger than
the just-ended Solar Cycle 24 (sunspot number of 116). The scientists say
it will also most likely be stronger than Solar Cycle 23 (sunspot number of
180). As the abstract explains:

"The sun exhibits a well-observed modulation in the number of spots on its
disk over a period of about 11 years. From the dawn of modern observational
astronomy, sunspots have presented a challenge to understanding -- their
quasi-periodic variation in number, first noted 175 years ago, stimulates
community-wide interest to this day. A large number of techniques are able
to explain the temporal landmarks, (geometric) shape, and amplitude of
sunspot 'cycles;' however, forecasting these features accurately in advance
remains elusive.

"Recent observationally motivated studies have illustrated a relationship
between the sun's 22-year magnetic cycle and the production of the sunspot
cycle landmarks and patterns, but not the amplitude of the sunspot cycle.
Using (discrete) Hilbert transforms on more than 270 years of (monthly)
sunspot numbers, we robustly identify the so-called 'termination' events
that mark the end of the previous 11-year sunspot cycle, the
enhancement/acceleration of the present cycle, and the end of 22-year
magnetic activity cycles. Using these, we extract a relationship between
the temporal spacing of terminators and the magnitude of sunspot cycles.

"Given this relationship and our prediction of a terminator event in 2020,
we deduce that Sunspot Cycle 25 could have a magnitude that rivals the top
few since records began. This outcome would be in stark contrast to the
community consensus estimate of Sunspot Cycle 25 magnitude."

McIntosh's recorded presentation of the paper is available at *this link*
<http://www.southgatearc.org/news/2020/november/Sunspot%20Cycle%2025%20could%20be%20among%20the%20strongest%20ever>
Use passcode z7qCn  3G

The research paper is at
https://arxiv.org/pdf/2006.15263.pdf

Source ARRL Letter November 19, 2020
http://www.arrl.org/arrlletter
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