Weather anomalies of the past and present: causes and consequences

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Weather anomalies of the past and present: causes and consequences
Weather anomalies of the past and present: causes and consequences
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Over the past 136 years, July 2016 has been the hottest month on the planet. This year is predicted to be the hottest in history. And this dynamic will continue. Is there a reason to sound the alarm? Or is it that what we call abnormal weather is actually a common occurrence. After all, temperature highs and lows, hurricane winds and floods have happened before. Naked Science looked into the climatic past of our planet and found some weather anomalies that can tell us something about the formation of weather.

Forest fires

Coldest year in history

If this year can go down in history as the hottest, then the coldest year for all the time of meteorological observations was 1816. This year went down in history as a “year without summer”. And the inhabitants of Europe and North America, that is, the Northern Hemisphere, were left without summer, and the cause of the anomaly, as it turned out later, was in the Southern.

The fact that something was going wrong was already felt in March. The first month of spring did not please with thaws, and winter continued. April and May were rainy as never before, hail often fell. And in Canada, many days of snowfalls begin in April. In early June, snow falls in Europe as well. Bavaria and England will be under the snow cover. June and July in America were marked by frost. At the end of August, frosts return to England again. Added to this are the rivers overflowing the banks. Potatoes are rotting on the vine, the wheat harvest is dying. By the next year, 1817, the price of grain was reaching unprecedented heights. In general, the temperature dropped by 0, 4–0, 7 ° C, but in some regions by all 3–5 ° C, but this was already enough to cause numerous disasters. Residents of many European countries are removed from their homes and, fleeing hunger, go across the ocean to America. But the Americans themselves, who also suffer no less than the Europeans, are leaving their homes. Immigrant carts moved from the east coast to the west and south.

A suitable explanation for the weather anomaly was found only in 1920. American climatologist and physicist William Humphreys suggested that the cause of the "year without summer" was the eruption of the Tambora volcano on the island of Sumbawa in Indonesia (at that time, the Dutch East Indies) that happened a year earlier. One of the largest eruptions in human history began on April 5, 1815 after a violent explosion, the thunderous sound of which was heard 1400 kilometers from the volcano. It lasted until April 12. By some estimates, 150-180 cubic kilometers of volcanic material were erupted. During the eruption, the height of the volcano decreased from 4300 meters to 2700-2800 meters. For two or three days, there was pitch darkness within a radius of 600 kilometers. But in Europe, the consequences of the eruption were not immediately felt; it took several more months for the ash to spread through the earth's atmosphere.

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In the Northern Hemisphere, such massive ash ejection into the atmosphere caused the effect of a volcanic winter. A volcanic winter, which has almost the same nature as a hypothetical nuclear winter, is a cooling of the planet's climate due to atmospheric pollution by ash from a very large volcanic eruption. Having reached the stratosphere, ash and sulfurous gases envelop the entire planet like a blanket.And even though this "blanket" looks quite transparent, it is quite enough for the solar radiation to be screened by the atmosphere more than usual. As a result, the Sun cannot adequately heat the planet. This is called the anti-greenhouse effect.

Another sharp drop in temperature in the Northern Hemisphere, which occurred in 535-536, is also associated with volcanic eruptions. Then the culprits were the volcanoes Krakatau (located again on the territory of modern Indonesia) and Tavurvur (in Papua New Guinea, neighboring Indonesia).

Temperature anomalies in Russia in 2010 and 2012

The abnormally hot summer of 2010 was, according to some estimates, the hottest in a thousand years. Unusually hot weather came first of all to the European territory of Russia. The thermometer rose to 40–45 degrees. Many cities and regions were shrouded in smog. The heat has become one of the causes of massive fires, primarily forest fires. The cause of the temperature anomaly was the so-called "blocking" anticyclone, which held out over the territory of Russia for more than two months. Blocking is called powerful anticyclones, which have the ability to prevent other air masses from entering the occupied territory. Although, as a rule, the average lifespan of such anticyclones varies from three to five days, and only rare of them can last up to 15 days.

It is noteworthy that the report of the US National Oceanic and Atmospheric Administration published in late August 2010 did not find a direct connection between the anomalous anticyclone and global warming.

The heat of 2012 in the number of temperature records yielded to the indicators of 2010, but exceeded in duration and coverage of the territory. However, the reasons for both weather anomalies were similar. The blocking anticyclone was formed in May and reached its peak in early July. But unlike the events of 2010, this time the heat affected less populated areas. A smaller number of the population fell under the influence of the temperature anomaly. It was noted that the heat of 2012 was less covered by the federal media, since it almost did not touch Moscow and the central regions.

Another thing is the consequences of these two seemingly similar temperature anomalies. If the heat of 2010 had negative consequences more for people, then the 2012 anomaly had a negative impact on nature. It affected the sensitive elements of natural systems: the mountain systems of the Urals, Altai, Sayan, ecosystems of the steppes of the south of Western Siberia, taiga, permafrost zones, glaciers, the Arctic and so on. In the Omsk Region and Altai Territory, the border of desertification has moved to the northeast by 20–40 kilometers. In the Tomsk region, soil erosion began in the burnt-out areas of the taiga. Self-healing of the affected ecosystems will require suitable climatic conditions for many years to come.

Abnormal frosts in Russia and Europe in 2012

The rampant winter in Europe fell on the beginning of 2012. A snow blanket enveloped the cities, and ice bound reservoirs in those places where residents had not really seen snow before. In Venice and Holland, canals were frozen because of the abnormal cold weather. The Dutch went on skates, just like the heroes of the paintings by Pieter Bruegel the Elder. And the Venice Carnival, which takes place annually in February, almost became a holiday on ice. At night in Venice, the thermometer dropped to –15 ° C, during the day it was –5-8 ° C. But the carnival did take place. The heavy snowfall that fell on Rome covered the ancient Colosseum with snow. Even the famous "Manneken Pis" in Brussels stopped "doing his job." The authorities, fearing for the "health" of the monument, cut off the water supply.

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In the European part of Russia, the temperature dropped by 7-12 degrees below normal. In Smolensk, the temperature dropped to -30 ° C, in Dagestan - to -15 ° C, and at the cold pole of Oymyakon dropped to -53 ° C.The reason for the unprecedented frosts is the Siberian anticyclone, which this time spread far to the west. The Siberian anticyclone, also known as the Asian anticyclone, or the Asian maximum, is a stable cold area of ​​high atmospheric pressure, which is located over Central Asia and Siberia for almost the entire winter. It is he who has a serious impact on the formation of the climate in a significant part of Russia. The Siberian anticyclone is a seasonal phenomenon; it appears over the continent every winter. Just like its younger brother, the Canadian Anticyclone, which is cooling the territory of North America at this time. Sometimes the Canadian anticyclone overcomes the Rocky Mountains, which usually stop its spread, and brings cold air to the southwestern United States and Mexico, where, as in Europe, they are not used to cold winters.

Little Ice Age

In general, Europeans are certainly not used to cold winters. But in the history of the Earth there was a period of global cooling, which did not bypass Europe. Over time, when the glacier covered a significant part of Europe, it certainly cannot be compared, which is why it was called the Little Ice Age. It fell on the XIV-XIX centuries and had three phases. Its beginning is considered to be the second decade of the XIV century. If the summer of 1311 was traditionally warm, then the next four years in a row were marked by extremely gloomy and rainy summers and severe cold winters. Orchards and vineyards were frozen. Grain harvests were dying. Frosts and snowfalls even reached Italy. As a result, there was a mass famine in Europe in 1315-1317, which went down in history as the “Great Famine”. In Russia, this phase is marked by a succession of "rainy years". It was only from the 1370s that the temperature began to rise slowly.

The second phase was marked by a temporary rise in temperature. And if the Gulf Stream, which is the main "supplier" of heat to Europe, was blamed for the coming cold, then the reason for the "thaw" was probably a temporary increase in solar activity. It was she who partially repaid the effect of the slowing down of the Gulf Stream.

But the coldest period of the Little Ice Age was its third phase, which fell on the 17th - early 19th centuries. Here, not only was the lack of heat brought by the Gulf Stream affected, but also the decrease in the level of solar activity. These two factors have sharply lowered the average annual temperature in Europe. The Moskva River, the Thames and the Danube were also frozen. The winter of 1708–1709 became especially cold. Winter went down in the history of Great Britain as the "Great Frost". In France, it was named "The Great Winter".

This winter also played a big role in the history of our country. The army of Charles XII, which invaded in the fall of 1708, lost almost half of its soldiers in a few months of winter. And this had a significant impact on the outcome of the Battle of Poltava, which took place in the summer of 1709.

The Little Ice Age had a significant impact on culture. Winter scenes appear in the paintings and miniatures of European artists, which have become reliable evidence of that era. The famous violins of Antonio Stradivari cannot be repeated precisely because trees that survived the abnormal cold served as the material for their manufacture.

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2016 and beyond …

So, the entire current year, with a 99% probability, may become the hottest in the entire history of meteorological observations. What is the reason for the warming? If we take the month of July, then in comparison with the pre-industrial era, it has become 1, 3 degrees warmer. But only 0.2 degrees of this indicator, experts associate with El Niño - fluctuations in the temperature of the surface layer of water in the equatorial part of the Pacific Ocean, which has a significant impact on the climate of the planet. The remaining 1, 1 degree increase is caused by global warming. Which, in turn, is explained by anthropogenic influence on the climate. Combustion of hydrocarbon fuels, deforestation, and so on. Growth in greenhouse gas emissions, primarily CO2, leads to an increase in the greenhouse effect and, as a consequence, to an increase in temperature at the planet's surface.

Returning to the Little Ice Age, it is worth noting that critics of the concept of anthropogenic influence on the climate and the global warming caused by it use this period of human history as an argument that they are right. In their opinion, the warming now observed is nothing but the exit from the third phase of the Little Ice Age. There is nothing surprising in the fact that the beginning of the century was marked by temperature highs and exceeding "climatic norms". After all, the norms themselves were determined by the cold 19th century.

And, in fact, can the climate have norms? Perhaps there is only one norm - constant variability? However, this does not cancel the main trend - now the warming continues. Already the glaciers of Antarctica began to be covered with summer thawed lakes. And apparently during the lifetime of our generation, this dynamic will continue. Even if we do not know its true cause - the anthropogenic factor or the exit from the Little Ice Age, we should be patient, hot years are ahead of us. And this is already, if not a cause for alarm, then, at least, an incentive to start planting forests, it certainly will not be worse.

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