The magnetic fields loop around, and cross over each other, cutting each other off, and reconnecting. You have probably seen what happens when you sprinkle iron filings on a bar magnet.
The iron filings line up along the magnetic lines of force. Similarly, the hot plasma on the Sun's surface is at the mercy of the magnetic lines of force. Sometimes the plasma gets disconnected from the magnetic fields when the fields interact with each other. Then particles in the hot, charged plasma can be accelerated to great speed and send powerful radiation into space.
This is a solar flare. The frequency of solar flares coincides with the Sun's year cycle. When the solar cycle is at a minimum, active regions are small and rare and few solar flares are detected. These increase in number as the Sun approaches the maximum part of its cycle. Sometimes, the Sun throws off huge amounts of matter. These events are called coronal mass ejections, or CMEs.
A CME can release up to 20 billion tons of this material. If that material were rock, it would make a mountain roughly 2. Solar flares and CMEs are the biggest, most violent "explosions" in our solar system, releasing the power of around one billion hydrogen bombs! Fast CMEs occur more often near the peak of the year solar cycle, and can trigger major disturbances in Earth's magnetosphere.
When Earth is in the path of a CME, we get "space weather. They occur when the charged solar particles follow the Earth's magnetic lines of force right down into the atmosphere at the poles.
The number of sunspots observed on the " surface " of the Sun varies from year to year. This rise and fall in sunspot counts varies in a cyclical way; the length of the cycle is around eleven years on average. The cyclical variation in sunspot counts, discovered in by the amateur German astronomer Samuel Heinrich Schwabe, is called "the Sunspot Cycle".
A peak in the sunspot count is referred to as a time of "solar maximum" or "solar max" , whereas a period when few sunspots appear is called a "solar minimum" or "solar min". An example of a recent sunspot cycle spans the years from the solar min in , when 13 sunspots were seen, through the solar max in when more than sunspots appeared, on to the next solar min in ten years after the solar min when the sunspot count had fallen back down to fewer than 9.
Along with the number of sunspots, the location of sunspots varies throughout the sunspot cycle. There is often an overlap in this latitudinal migration trend around solar min, when sunspots of the outgoing cycle are forming at low latitudes and sunspots of the upcoming cycle begin to form at high latitudes once again. In another English astronomer, Edward Walter Maunder, constructed the first "butterfly diagram", a graphical plot of this sunspot migration trend. The duration of the sunspot cycle is, on average, around eleven years.
However, the length of the cycle does vary. Between and the present, the sunspot cycle from one solar min to the next solar min has varied in length from as short as nine years to as long as fourteen years.
Note, however, that of the 26 solar cycles during that three-century span, 21 had a length between ten and twelve years. Arriving at a precise count of sunspots is not as straightforward as it might appear. A typical spot consists of a dark region called the umbra , surrounded by a lighter region known as the penumbra. The sunspots appear relatively dark because the surrounding surface of the Sun the photosphere is about 10, degrees F.
Sunspots are quite large as an average size is about the same size as the Earth. 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. In just a few minutes, the flares heat to several million degrees F. They occur near sunspots, usually at the dividing line between areas of oppositely directed magnetic fields.
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. Solar flares emit x-rays and magnetic fields which bombard the Earth as geomagnetic storms. 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. The Solar Cycle: Sunspots increase and decrease through an average cycle of 11 years.
Dating back to , 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. Daily observations of sunspots began in 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 to This period of sunspot minima is called 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 s of years. Times of maximum sunspot activity are associated with a very slight increase in the energy output from the sun.
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