Background.
Solar cycle 25 is recognized as having started in November. A solar cycle is marked by increased sunspot appearance and activity.
Leading-up to November, our sun had been active in tossing-out coronal mass. Although it is predicted that this solar cycle is not going to be overall very active (relative to past cycles); we have already seen a marked increase in activity, even before this one officially began.
As we head into Cycle #25, we are seeing increased solar activity. A variety of interesting phenomena is occurring, It's important to understand the basic vocabulary.
If we are identifying a solar cycle based on the prevalence of sunspots, it would be nice to know what one is.
Before this, it might be nice to know what a sunspot is...
Little introduction to this video. This is a reading of material I've collected from online. I needed to provide a common vocabulary (lexicon) of phrases, first and foremost, as the time is running short. This is simply the spoken text. a livestream is intended to show the images that would otherwise accompany this work.
Keywords: solar cycle, cme, solar flare, solar wind, plasma, magnetic field.
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- Solar Cycle: What is a 'solar cycle' ?
" Our Sun is a huge ball of electrically-charged hot gas. This charged gas moves, generating a powerful magnetic field. The Sun's magnetic field goes through a cycle, called the solar cycle.
" Every 11 years or so, the Sun's magnetic field completely flips.
" This means that the Sun's north and south poles switch places.
" Then it takes about another 11 years for the Sun’s north and south poles to flip back again.
" The solar cycle affects activity on the surface of the Sun, such as sunspots which are caused by the Sun's magnetic fields.
" As the magnetic fields change, so does the amount of activity on the Sun's surface. "
Source: Spaceplace updated September 10, 2020 [4). -link below]. [ 4). (https://spaceplace.nasa.gov/solar-cycles/en/) ]
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- Sunspot: What is a 'sunspot' ?
" Sunspots are darker, cooler areas on the surface of the sun in a region called the photosphere.
" The photosphere has a temperature of 5,800 degrees Kelvin. Sunspots have temperatures of about 3,800 degrees K.
" They look dark only in comparison with the brighter and hotter regions of the photosphere around them.
" Sunspots can be very large, up to 50,000 kilometers in diameter. They are caused by interactions with the Sun's magnetic field which are not fully understood.
" But a sunspot is somewhat like the cap on a soda bottle: shake it up, and you can generate a big eruption.
" Sunspots occur over regions of intense magnetic activity, and when that energy is released, solar flares and big storms called coronal mass ejections erupt from sunspots. "
Source: By Space.com Staff about 9 years ago [5). -link below]. [5). (https://www.space.com/14736-sunspots-sun-spots-explained.html)]
- " Sunspot, vortex of gas on the surface of the Sun associated with strong local magnetic activity.
" Spots look dark only by contrast with the surrounding photosphere, which is several thousand degrees hotter.
" The dark centre of a spot is called the umbra; the outer, lighter ring is the penumbra.
" Spots may be several times larger than Earth or so small that telescopic observation is difficult. They may last for months.
" Single spots do appear, but most are in pairs or groups, with the members of a pair (leader and follower in respect to the direction of the Sun’s rotation) having opposite magnetic polarity.
" This polarity reverses from one solar cycle (of 11 years duration) to the next; i.e., if leaders in one cycle are north magnetic poles, leaders in the succeeding cycle will be south poles.
" Leaders and followers in one hemisphere of the Sun are almost always opposite in polarity from their counterparts across the equator.
" By observing spots, English astronomer Richard C. Carrington found (c. 1860) that the Sun rotates not as a solid body but differentially, fastest at the equator and slower at higher solar latitudes.
" Sunspots are never seen exactly at the equator or near the poles.
" George Ellery Hale in 1908 discovered their magnetic fields, which are about 2,000–4,000 gauss in strength.
" (Earth’s magnetic field has a strength of 1 gauss.)
" John Evershed in 1909 detected the radial motion of gas away from sunspot centres.
" Annie Russel Maunder in 1922 charted the latitude drift of spots during each solar cycle.
" Her chart is sometimes called the butterfly diagram because of the winglike shapes assumed by the graph.
" Each solar cycle begins with small spots appearing in middle latitudes of the Sun.
" Succeeding spots appear progressively closer to the Sun’s equator as the cycle reaches its maximum level of activity and declines."
Source: By Richard Pallardy, Research Editor [6). -link below] [6). (https://www.britannica.com/science/sunspot)]
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- Solar Wind: What is the 'solar wind' ?
" The solar wind is a flow of particles that comes off the sun at about one million miles per hour and travels throughout the entire solar system.
" First proposed in the 1950s by University of Chicago physicist Eugene Parker, the solar wind is visible in the halo around the sun during an eclipse and sometimes when the particles hit the Earth’s atmosphere—as the aurora borealis, or northern lights.
" While the solar wind protects Earth from other harmful particles coming from space, storms can also threaten our satellite and communications networks.
" The surface of the sun is blisteringly hot at 6,000 degrees Fahrenheit—but its atmosphere, called the corona, is more than a thousand times hotter.
" It is also incredibly active; those flares and loops are the halo you see around the sun when there’s an eclipse.
" The corona is so hot that the sun’s gravity can’t hold it, so particles are flung off into space and travel throughout the solar system in every direction.
" As the sun spins, burns and burps, it creates complex swirls and eddies of particles. These particles, mostly protons and electrons, are traveling about a million miles per hour as they pass Earth.
" This flow of particles, called the “solar wind,” has an enormous impact on our lives. It protects us from stray cosmic rays coming from elsewhere in the galaxy—but the effects of storms on the sun’s surface can also affect our telecommunications networks.
" The wind would also pose a threat to astronauts traveling through space, so NASA wants to get a better understanding of its properties.
" The science behind what is happening on the sun’s surface is enormously complex; read more about it at [NASA_link: (https://www.nasa.gov/feature/goddard/2018/parker-solar-probe-and-the-birth-of-the-solar-wind) ].
Source: By Louise Lerner [7). -link below].
[7). (https://news.uchicago.edu/explainer/what-is-solar-wind)]
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schumann-resonances weblink: (https://www.schumann-resonances.com/post/26-29-may-2021-what-is-a-solar-cycle-the-solar-wind-and-sunspots)
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