The converse is true during minimum sunspot activity. Ultraviolet radiation increases dramatically during high sunspot activity, which can have a large effect on the Earth's atmosphere. Times of maximum sunspot activity are associated with a very slight increase in the energy output from the sun. 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. 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. The "Little Ice Age" occurred over parts of Earth during the Maunder Minimum. This period of sunspot minima is called the Maunder Minimum. One interesting aspect of solar cycles is that the sun went through a period of near zero sunspot activity from about 1645 to 1715. (Daily observations of sunspots began in 1749 at the Zurich, Switzerland observatory.) 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. This chart from the NASA/Marshall Space Flight Center shows the sunspot number prediction for solar cycle 24.
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. The Solar Cycle: Sunspots increase and decrease through an average cycle of 11 years. 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. The storms can even change polarity in satellites which can damage sophisticated electronics. 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. If sunspots are active, more solar flares will result creating an increase in geomagnetic storm activity for Earth. Solar flares emit x-rays and magnetic fields which bombard the Earth as geomagnetic storms. Hot matter called plasma interacts with the magnetic field sending a burst of plasma up and away from the Sun in the form of a flare. They occur near sunspots, usually at the dividing line between areas of oppositely directed magnetic fields. and release as much energy as a billion megatons of TNT. In just a few minutes, the flares heat to several million degrees F. Sunspots, Solar Flares, Coronal Mass Ejections and their influence on Earth: Coronal Mass Ejections (shown left) and solar flares are extremely large explosions on the photosphere. Sunspots are quite large as an average size is about the same size as the Earth.
The sunspots appear relatively dark because the surrounding surface of the Sun (the photosphere) is about 10,000 degrees F., while the umbra is about 6,300 degrees F. A typical spot consists of a dark region called the umbra, surrounded by a lighter region known as the penumbra. Sunspots tend to occur in pairs that have magnetic fields pointing in opposite directions. This in turn lowers the temperature relative to its surroundings because the concentrated magnetic field inhibits the flow of hot, new gas from the Sun's interior to the surface. Because of the strong magnetic field, the magnetic pressure increases while the surrounding atmospheric pressure decreases. Sunspots are areas where the magnetic field is about 2,500 times stronger than Earth's, much higher than anywhere else on the Sun. Sunspots: One interesting aspect of the Sun is its sunspots.
After the red giant phase, the Sun will shrink to a white dwarf star (about the size of the Earth) and slowly cool for several billion more years.
The Sun at this point will be a "red giant" and 10,000 times brighter than its present luminosity. When the hydrogen is exhausted, the Sun's temperature at the surface will begin to cool and the outer layers will expand outward to near the orbit of Mars. This took roughly 4.5 billion years to accomplish. Right now, about half the amount of hydrogen in the core of the Sun has been fused into helium. Under these conditions, hydrogen atoms come so close together that they fuse. The Sun's core is an astonishing 29,000,000 degrees F., while the pressure is about 100 billion times the atmospheric pressure here on Earth. Can an increase or decrease in sunspot activityĪ typical star, the Sun has a diameter of approximately 865,000 miles (nearly 10 times larger than the diameter of Jupiter) and is composed primarily of hydrogen.