October 7, 2011 10:07
Astronomers predict: 10 years on the planet can start an ice age. But whether the case comes to the extremes?
Solar activity seems to be decreasing. This may result in catastrophic changes on our planet. Such fears scare several research groups. Like, the sun came very late in the next 11 years, the cycle of its activity. In — 24th. Next — the 25th, which is expected in 2020, may be late for a year or two. Or does not start. This was reflected in a series of alleged anomalous processes now in our luminary.
For example, with the sun disappearing spots. According to Matthew Penn and William Livingston (Matt Penn and William Livingston) of the U.S. National Solar Observatory (NSO), accumulated since 1990, even in the current cycle of sunspots is halved. And for the 25th cycle of the light is completely cleared. Means significantly reduced and its activity.
The team, led by Richard Altroka (Dr Richard Altrock), Astrophysics Research Laboratory of the U.S. Air Force (Air Force Research Laboratory) found strangeness in the movement of plasma flows inside the Sun. And, as a result, abnormal changes in magnetic fields. And from them, principally, that depends on the formation of spots. As a result, Altrok colleagues also spotted the extreme weakness in the coming 25-cycle of solar activity.
Another group of scientists did not see in the solar corona — the most hot and hectic part of the light — a characteristic feature of preparation of the 25th cycle. Usually they are — signs — become visible long before it began, when still under the previous cycle. At this time the area of activity begins to shift from high latitudes to the equator of the Sun. A new magnetic field pushes the remnants of the previous cycle to the poles. Such processes would have already begun. But they are not. And this worries.
If precursors weakening of solar activity are correct, the Earth waiting frosts even in summer.
So-called small ice ages occurred from 1310 to 1370 years, from 1645 to 1715. At that time, the number of sunspots is rapidly decreased as compared to "normal" years. Frozen Thames and the Seine, snowfall was even in the south of Italy.
Scientists, of course, can not provide an accurate prediction. But if solar activity will continue to decline, the strong cooling could begin in 2020. Or even earlier. And no global warming, caused by the action of human civilization, it will not stop.
Little Ice Age, we, of course. Survive. A big one? A very large?
One hypothesis is called "snowball Earth," our planet, at least once — in the Neoproterozoic era, about 700-800 million years ago — frozen, so that turned into a ball of ice. This was evidenced by the glacial sedimentary rocks found almost on the equator. It turned out that the ice at the time covered the current tropical areas. And God forbid, this again … It is unlikely that such a civilization survive the cataclysm.
Recently icy perspective a little "warmed" the researchers from France, USA, Brazil, and Malaysia, which are studied in detail the very glacial rocks (in Brazil), and they estimated the carbon dioxide concentration in that distant time. It was that absolutely in the "snowball" Earth never turned. And even in the tropics probably remained open water, plants and animals are kept. There and waited cataclysm.
In other words, if in the distant past glaciation was not quite so extreme, and now do not expect extreme. It is somehow reassuring.
Hot or cold
— Penn and Livingston analyzed not all spots, but only the largest, of which only a few percent —
said a senior researcher at the Institute of Solar-zemnoyfiziki RAS, Director of the Astronomical observatoriiIrkutskogo State University Sergei Yazev. — Due to the cold snap than the forecasts so far do not seem justified. As predictions of further warming.
From my point of view, will not happen either one or the other. Go fluctuations of some parameters change, that have been, are and will always be. But, of course, to the glaciers will not come.
The hypothesis that the cooling associated with sunspots actually exists. While it is not proven. But nor disproved.
Yes, in the period from 1645 to 1715 sunspots were very few (so-called Maunder minimum). At the same time in Europe was quite frosty. Most experts in the sun, and I among them, suggest that these events are related. But it is unlikely that simple — there are fewer spots, and once cold. If these phenomena are related, it is much more difficult — several stages. There is still much work to figure out exactly how.
— Are there any calculations that show how much sun should change their activity to the Earth came the Ice Age?
— Here, too, it's not easy. The Earth "adapts" to changes in solar radiation. For example, due to the fact that our planet is orbiting the Sun is not a circle, but an ellipse, then we are the closest to the luminary, the farthest. Due to this, the total flow of light and heat from the sun varies in the range of about 5 percent. But so much depends, for example, cloud cover. For example, the planet Venus, which is much closer to the Sun, however, receives a much lower heat of the Earth? A huge part of the solar radiation is reflected back into space by a thick layer of Venusian clouds that never gleams …
So does the Earth. When it gets too hot, increasing evaporation, clouds are formed, reflecting the sun's rays. As a result, the heat comes less. But then decreases evaporation and therefore becomes less clouds and more heat again bubbling to the surface of our planet … Excellent system of automatic temperature control!
Therefore, not only from changes in solar radiation depends on the temperature of the Earth, but mainly on the processes in the atmosphere and in the ocean — both distributed and redistributed the heat in the Earth's shells. Compared to these factors, the Sun is a very stable source of energy. Due to fluctuations in solar activity, the fluctuations of the total heat flux vary by no more than 0.5 percent. This is 10 times less than, say, due to the motion of the Earth around the Sun.
On our planet, there are dozens of complex physical natural mechanisms that act in the line, and in the opposite direction, smoothing, and, conversely, increasing external influences. If they were not, the average temperature would be rocked with a large amplitude, of the terrible killing frosts to heat. The climate of the planet is well balanced car — because of that life on our planet has successfully existed for nearly 4 billion years …