Life on earth depends on the sun. In particular, it is solar activity can affect the Earth's climate changes. Now the solar cycle moves to its maximum. How this can be fraught with us? However, no major accidents should not happen, promise scientists as they happened in the previous four hundred years of observations.
By solar activity implies the appearance of sunspots, whose number may at certain times to peak and then fall to a minimum. For the first time such a spot was recorded in 1611. The discovery has astonished astronomers previously considered our star something changed.
It was later revealed that the number of sunspots varies, but not randomly: first increases and then starts to go down. This cycle can last from eight to fourteen years old, but most of all — about odinnadtsati.Chem more spots, the more frequently occurring coronary emissions solar masses, and then we can talk about the increased solar activity.
Meanwhile, solar cycles may differ significantly from each other in intensity. Sometimes up this cycle is very difficult to distinguish from the minimum. For example, this situation occurred in the years 1645-1715 (the so-called Maunder minimum, named after the English astronomer Edward Walter Maunder, who discovered the phenomenon). The number of spots on the sun then significantly decreased. During this period, it was only about 50 instead of the usual 40-50 thousand. The vast majority of spots observed in the southern hemisphere of the Sun.
This coincided with the so-called small ice age that lasted roughly from the XIV to XIX century: whereas in Europe and America has an unusually cold weather (average temperature over the last two thousand years has been minimal). If the X-XIII centuries, the weather was relatively smooth and warm, with mild winters and no droughts, already in 1310's of the heavy rains and severe winters have contributed to the death of crops and freezing of fruit gardens in England, Scotland, Northern France, and Germany.
Frequent frosts and snowfalls were observed even in the south of Europe. On the east coast of America, apparently, had a strong cooling, and in the central and western regions of the United States today — very dry weather with dust storms. Since the end of XV century in many mountain regions and polar glaciers offensive began.
In the XVI century, the average annual temperature increased slightly, the winters are milder. But in the next century, global temperatures fell by 1-2 degrees Celsius. Thames, the Danube, the Bosphorus and the Adriatic Sea during the winter freeze. Also decreased the intensity of the aurora and reduce the speed of the sun.
Despite the fact that the Little Ice Age lasted longer than the solar Maunder minimum, one of his main reasons (along with a slowing Gulf Stream and volcanic activity), researchers still believe decrease in solar activity. This was later confirmed by the analysis of carbon-14, and a number of other isotopes, such as beryllium-10, in the trees and glaciers. It is also interesting that the Maunder minimum coincides almost exactly with the period of the last French monarch Louis XIV (1643-1715), which, as you know, called the "Sun King."
So, according to scientists in the past 8,000 years have been found to be 18 minimum solar activity. The most famous of them — at least Sporer (1450-1540) and the Dalton minimum (1790-1820). By the way, not so long ago, our star is also characterized by minimal activity.
Causes of sunspots became clear to scientists only in the first half of the XX century. It turned out that these spots are magnetic in nature. As shown gelioseysmicheskoe study magnetized material inside the sun unstable: it moves, rising to the surface, and will eventually result in a change of the poles. Full cycle, when the poles "return" to his place in 22 years, but the 11-year-old is better known because it is easier to "catch" with the calculations and observations.
Today, say the researchers, the solar cycle moves to the maximum, so the flare and coronal mass ejections are more often than a few years ago. By the end of 2013 or beginning of 2014, solar activity will reach its peak and then starts to decline. Minimum expected in 2020.
The current cycle is different in that it is the slowest in the history of space-based observations. This allowed the scientists to suggest that the next solar maximum can be characterized by a relatively small number of spots. However, this is unlikely to have a serious impact on the Earth and humanity.