Solar Activity, Solar Cycle Predictions, and Sunspots

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Welcome to our page on solar flares and activity, solar cycle predictions, and sunspots. At The Old Farmer's Almanac, solar science is one of the disciplines we use to make our long-range weather predictions.

What is Solar Activity?

The Sun is always active. Sunspots are magnetic storms on the surface of the Sun.

Solar flares are intense bursts of radiation that come from the release of the magnetic energy associated with sunspots.

Other solar events include: coronal mass ejections (CMEs), clouds of plasma and magnetic fields that erupt from the sun; solar wind streams that come from the coronal holes on the Sun; and solar energetic particles that are primarily release by CMEs.

What is a Solar Cycle?

The solar cycle—also called the sunspot cycle—is approximately 11 years long. During a cycle, solar activity begins at a low point, rises to a peak, and then drops again. 

At solar minimum, the Sun may go for many days without any sunspots; at solar maximum, there can be 200 sunspots per day!

This rhythm is compared to the pulse of the Sun. Since the 18th century, we've been recording solar cycles, observing the Sun as it grows dimmer and quieter, then brighter and stormer, then dimmer again.

How Does Solar Activity Affect Earth?

Solar activity affects the Earth in many ways, some which we are still coming to understand.

1. An active Sun can generate geomagnetic storms that damage 21st-century satellites and other high-tech systems in space—from GPS navigation to power grids to air travel to financial services.
2. A quiet Sun usually means weak solar winds, which may allow more galactic cosmic rays into the inner solar system. This can pose radiation hazards for astronauts and satellites.
3. Weather on Earth can also be affected. Recently, NOAA scientists finally concluded that four factors determined global temperatures: carbon dioxide levels, volcanic eruptions, Pacific El Nino pattern, and the Sun's activity. 

At the Almanac, we believe solar cycles may also affect the ocean and the land, though the effects take time and are not immediately obvious. Sunlight that brings heat may influence El Nino, La Nina, and other weather events.

There is also historical evidence that long-term periods of global cold, rainfall, drought, and other weather shifts relate to solar cycle activity:

• Times of depressed solar activity seem to correspond with times of global cold. For example, during the 70-year period from 1645 to 1715, few if any sunspots were seen, even during expected sunspot maximums. Western Europe entered a climate period known as the "Little Ice Age." Temperatures dropped by 1.8 to 2.7 degrees Fahrenheit.
• Times of increased solar activity have corresponded with global warning. During the 12th and 13th centuries, the Sun was active, and the European climate was quite mild.

When is the Solar Minimum?

According to NOAA and NASA, sunspot activity reached an extremely unusual and deep "solar minimum" from 2007 to 2009.

In 2008 and 2009, there were almost no sunspots, a very unusual situation that had not happened for almost a century. Due to the weak solar activity, galactic cosmic rays were at record levels.

When is the Solar Maximum?

The Sun's record-breaking sleep ended in 2010. We are now in Solar Cycle 24, headed for a peak or maximum in mid-2013, as early as May. Most experts predict that the cycle will be exceptionally quiet, producing a lower number of sunspots than the average cycle. 

In addition, Cycle 24 took a long time to get under way. Some theorists believe there is not only a correlation between level of solar activity and Earth's temperatures, but also the length of the solar cycle. 

The low solar activity levels and the delayed start to the solar cycle reinforce our believe that we're in a cooling phase.

Of course, even a below-average sunspot count does not preclude a large solar flare—which could cause billions of dollars in damage to the world's high-tech infrastructure.

What's Up With the Sun Now?

Late 2009 brought a burst of activity, and December ended with a flurry of sunspots.

During 2010, solar activity increased with several intense periods of eruption, sometimes all at once. NASA stated that "the Sun is waking up from a deep slumber, and the next few years could bring much higher levels of solar activity.

As of mid-2011, however, the Sun seemed to be going into another quiet phase with solar readings with fading sunspots and low magnetic activity near the poles. Many researchers believe the upcoming solar maximum may be weak.

To quote Bob Berman, astronomer for The Old Farmer's Almanac, "If the upcoming solar max of cycle 24 is normal or robust, and especially if an El Nino follows it two years later (as often happens), then the middle of this decade will be the hottest period since humans arrived on Earth. However, if the upcoming maximum is wimpy, as most solar researchers expect, or if the sun is now entering an extended period of low activity, that is the best thing it could possibly do for us. Such a scenario would mitigate climate change. Essentially, the sun has been buying us time."

One could also argue that cooling from solar effects is masking effects of human activity. Many solar scientists believe that both Cycle 24 and the following cycle (25) may be relatively quiet ones, leading to a cooling pattern over the next few decades, and raise the question of whether an eventual warming cycle could lead to more rapid warming on Earth that expected. The question is the interplay between many factors; weather is a complex system.

Stay tuned. We'll continue to update this sunspot page to keep you abreast of new discoveries and learning!

In the meantime, enjoy the Sun's light show, otherwise known as the Northern Lights! This colorful event is caused by solar winds. Learn more about the Aurora Borealis.