ANATOMY OF A SUNSPOT

Jan 27, 2020
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National Weather Service
NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION
Spaceweather.com
07 September 21

For the first time in years, there are multiple large spots on the sun. Yesterday in Austria, astronomer Michael Karrer zoomed in on one of them, and this is what he saw:

"It took some patience," he says. "I waited until the air was perfectly still and free of turbulence, then took a high-resolution picture of sunspot AR2868." He used a 14-inch Celestron telescope, safely filtered.

In fact, the image above is only a fraction of the total. The whole sunspot is enormous. AR2868 sprawls more than 110,000 km from end to end.

Austria's moment of atmospheric clarity combined with the sheer scale of the sunspot allowed Karrer to capture details rarely seen in amateur photos. There's the dark umbra, the filamentary penumbra, a crack in the sunspot known as a "light bridge," dark pores, and boiling granules the size of North America.

primarycore_lab.jpg
primary core_lab.jpg

Dating back to 1749, we have experienced 23 full solar cycles where the number of sunspots have gone from a minimum, to a maximum and back to the next minimum, through approximate 11 year cycles. We are now well into the 24th cycle. This chart from the NASA/Marshall Space Flight Center shows the sunspot number prediction for solar cycle 24. The NASA/Marshall Space Flight Center also shows the monthly averaged sunspot numbers based on the International Sunspot Number of all solar cycles dating back to 1750. (Daily observations of sunspots began in 1749 at the Zurich, Switzerland observatory.)

One interesting aspect of solar cycles is that the sun went through a period of near zero sunspot activity from about 1645 to 1715. This period of sunspot minima is called the Maunder Minimum. The "Little Ice Age" occurred over parts of Earth during the foregoing Maunder Minimum. So how much does the solar output affect Earth's climate? There is debate within the scientific community how much solar activity can, or does affect Earth's climate. There is research which shows evidence that Earth's climate is sensitive to very weak changes in the Sun's energy output over time frames of 10s and 100s of years. Times of maximum sunspot activity are associated with a very slight increase in the energy output from the sun.

If sunspots are active, more solar flares will result creating an increase in geomagnetic storm activity for Earth. Therefore during sunspot maximums, the Earth will see an increase in the Northern and Southern Lights and a possible disruption in radio transmissions and power grids. The storms can even change polarity in satellites which can damage sophisticated electronics. Therefore scientists will often times preposition satellites to a different orientation to protect them from increased solar radiation when a strong solar flare or coronal mass ejection has occurred.

Sunspots increase and decrease through an average cycle of 11 years. Dating back to 1749, we have experienced 23 full solar cycles where the number of sunspots have gone from a minimum, to a maximum and back to the next minimum, through approximate 11 year cycles. We are now well into the 24th cycle. This chart from the NASA/Marshall Space Flight Center shows the sunspot number prediction for solar cycle 24. The NASA/Marshall Space Flight Center also shows the monthly averaged sunspot numbers based on the International Sunspot Number of all solar cycles dating back to 1750. (Daily observations of sunspots began in 1749 at the Zurich, Switzerland observatory, see below.)

Sunspot_Numbers-400 yrs.jpg
theguardian.com

One interesting aspect of solar cycles is that the sun went through a period of near zero sunspot activity from about 1645 to 1715. This period of sunspot minima is called the Maunder Minimum. The "Little Ice Age" occurred over parts of Earth during the Maunder Minimum. So how much does the solar output affect Earth's climate? There is debate within the scientific community how much solar activity can, or does affect Earth's climate. There is research which shows evidence that Earth's climate is sensitive to very weak changes in the Sun's energy output over time frames of 10s and 100s of years.

Times of maximum sunspot activity are associated with a very slight increase in the energy output from the sun. Ultraviolet radiation increases dramatically during high sunspot activity, which can have a large effect on the Earth's atmosphere. The converse is true during minimum sunspot activity. But trying to filter the influence of the Sun's energy output and its effect on our climate with the "noise" created by a complex interaction between our atmosphere, land and oceans can be difficult. For example, there is research which shows that the Maunder Minimum not only occurred during a time with a decided lack of sunspot activity, but also coincided with a multi-decade episode of large volcanic eruptions. Large volcanic eruptions are known to hinder incoming solar radiation.

Finally, there is also evidence that some of the major ice ages Earth has experienced were caused by Earth being deviated from its average 23.5 degree tilt on its axis. Indeed Earth has tilted anywhere from near 22 degrees to 24.5 degrees on its axis. But overall when examining Earth on a global scale, and over long periods of time, it is certain that the solar energy output does have an affect on Earth's climate. However there will always be a question to the degree of affect due to terrestrial and oceanic interactions on Earth.


Ultraviolet radiation increases dramatically during high sunspot activity, which can have a large effect on the Earth's atmosphere. The converse is true during minimum sunspot activity. But trying to filter the influence of the Sun's energy output and its effect on our climate with the "noise" created by a complex interaction between our atmosphere, land and oceans can be difficult. For example, there is research which shows that the Maunder Minimum not only occurred during a time with a decided lack of sunspot activity, but also coincided with a multi-decade episode of large volcanic eruptions. Large volcanic eruptions are known to hinder incoming solar radiation.

The entire planet Jupiter could fit comfortably between the primary cores of AR2868 (on the right). AR2866 (on the left) might soon be even bigger. The active region has almost doubled in size since yesterday.

Big sunspots can produce big flares. For the rest of this week, the two will be squarely inside the Earth strike-zone. Any flare or CME will be a direct hit.

mdi_sunspots.9:7:21.jpg

Finally, there is also evidence that some of the major ice ages Earth has experienced were caused by Earth being deviated from its average 23.5 degree tilt on its axis. Indeed Earth has tilted anywhere from near 22 degrees to 24.5 degrees on its axis. But overall when examining Earth on a global scale, and over long periods of time, it is certain that the solar energy output does have an affect on Earth's climate. However there will always be a question to the degree of affect due to terrestrial and oceanic interactions on Earth.

See: https://spaceweather.com

See: https://www.weather.gov/phi/spacewx

See: https://www.noaa.gov/education/resource-collections/weather-atmosphere/space-weather

Sunspots are areas on the Sun's surface where the magnetic field is about 2,500 times stronger than Earth's, much higher than anywhere else on the Sun. Because of the strong magnetic field, the magnetic pressure increases while the surrounding pressure decreases. This in turn lowers the temperature relative to its surroundings because the strength of the concentrated magnetic field inhibits the inflow of hot, new gas from the Sun's interior to the surface. Sunspots often occur in pairs, where each one has a magnetic field with an opposite polarity. A typical spot consists of a dark region called the umbra, surrounded by a lighter region known as the penumbra and often have a light bridge, a narrow piece of the penumbra, spanning the umbra. The sunspots appear relatively dark because the surrounding photosphere is about 10,000 degrees F, while the umbra is about 6,300 degrees F. Sunspots are quite large as an average size is about the same size as the Earth, although two of the current sun spots are approaching that of Jupiter. Sunspots, our planet, weather, communications.
Hartmann352
 
Last edited:
Jul 29, 2021
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Recently stargazers in the same way paid a lot of attention to the Sun spots observation.
Yes, the sunspots are reported to be flaring.

AR2865 produced a B7-class solar flare.
The consequences are expected on September 8-9.
It is important to be heads up on different levels of observing and reporting such events.
All together, National/international monitoring (e. g. SOHO), any contributing companies monitoring.
Still, the Sun is unpredictable and dangerous.

Thank you.
 

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