Oct 16, 2020
The Maunder minimum is the name given to the period that goes from about 1645 to 1715 and which was characterized by very low solar activity, i.e. a situation in which the number of sunspots became extremely low. It is named after the British solar astronomers Edward Walter Maunder and Annie Russell Maunder who lived between the nineteenth and twentieth centuries, who discovered the lack of sunspots at that time by studying the chronicles of the time. For example, over a 30-year period during the Maunder Minimum, astronomers observed only about 50 spots, instead of the normal 40,000 or 50,000.
Maunder Minimum of 1709
The beginning of the Maunder Minimum was abrupt and took place in a few years, without any precursor phenomenon, however during its final phase, between 1700 and 1712, solar activity gradually began to increase.
The Maunder Minimum coincided with the central and colder part of the so-called Little Ice Age, during which Europe and North America, and perhaps the rest of the world (for which there is no reliable data) experienced extremely cold winters .
Recently published data suggests that during the Maunder minimum the Sun expanded and its rotation slowed down. A larger, slower rotating Sun is also assumed to be a colder Sun, which provides less heat to the Earth (the reason for the expansion and contraction of the Sun is not yet known, but it could be a normal cycle of activity similar to the cycle. solar eleven years, only much longer).
A cause-and-effect relationship between low sunspot activity and colder winters is still under debate. A study conducted by Gerald Meehl and colleagues from the National Center for Atmospheric Studies of the United States of America in the first decade of the 2000s actually appears to show a correlation between sunspots (and therefore sun activity) with climate cycles, although the model has raised some criticisms related to the short period on which it was tested and on the simplifications it induced in the modeling of the ocean-atmosphere system.
Between January and April 1709 the European continent was hit by an abnormal cold wave that paralyzed the entire region, causing a high number of victims among the population
The great winter, remembered as the coldest and most disastrous of the last five centuries, began on the eve of the Epiphany of 1709. The following day, Western Europe and part of the Mediterranean basin woke up under a blanket of ice that remained for different months. Scandinavia and part of Turkey were excluded from the cold wave.
The reasons for this unexpected and extraordinary polar cold in most of these regions is to be found in some climatic changes of our planet. In addition to the eruption in previous years of several volcanoes, including that of Santorini, in Greece, Vesuvius, Fuji in Japan and the Teide of Tenerife, two phenomena occurred which, combined together, gripped the planet in the grip of ice: the culmination of the so-called “Little Ice Age” and the prevalence of the Russian thermal anticyclone.
The first term usually indicates the general and radical cooling that occurred in the Old Continent starting from the Middle Ages and which, from the mid-nineteenth century, gave way to the opposite phenomenon. Some argue that these glaciations are the consequence of periodic variations in solar intensity: every 250-300 years the Sun decreases its activity, as it happened in 1709, when the so-called Maunder Minimum was recorded and the emission of solar energy decreased. significantly.
The second factor, the Russian anticyclone, also called “bear” by experts, concerns a large area of high pressure and low temperatures: it is a phenomenon that always occurs in the atmosphere in western Asian regions, usually opposed by currents from the Atlantic. However, if these fail to prevail, temperatures plummet. In 1709, the anticyclone, which had heavily affected Russia during the previous winter, expanded and also invested Europe.
According to the reports we have received, the Paris thermometers recorded a temperature range of about 30 degrees in a few hours. In Italy, for about twenty days the Po Valley was stuck in an unusual grip of frost with temperatures that even reached -40 ° C. According to a story of the time: “So much snow fell that you could not leave the house and the roofs, due to the huge ponde, had incredible ruin, after which some opened and others fell”. The only existing meteorological observatory was that of Berlin which recorded an average temperature of the month of -8.7 ° C and a minimum of -29.4.
The rivers, the network of canals and even the seaports were blocked by ice. The Vistula, the Rhine, the Danube, the Meuse, the Garonne, the Ebro, the Seine, and even the mouth of the Tagus in Lisbon, as well as Lake Constance and Lake Zurich, and, partially, that of Geneva froze. The Mediterranean ports of Genoa, Marseille and Livorno also suffered the same fate. Snow completely covered the streets. They could no longer find basic necessities and, as firewood was scarce, the inhabitants burned their furniture to keep warm.
The whole continent in crisis
The great cold did not spare anyone, not even the stately homes, equipped with large windows that offered no thermal insulation. At Versailles, Elizabeth Charlotte of the Palatinate, Duchess of Orleans, sister-in-law of King Louis XIV, wrote to a relative in Hanover: “I am sitting here in front of a big fire, I have a screen in front of the door, I am barricaded in the house, with an ermine fur around the neck and a bear fur on the feet. I am so cold that I can barely hold the pen to write to you. I’ve never seen a winter like this in my life. ‘
The sudden drop in temperature made the wine in the cellars of Versailles freeze in the barrels. The consequences on animals and plants were dramatic: the fish froze in the rivers, thousands of birds died and, especially in our country, in Liguria and in Emilia Romagna, all fruit plants, such as apple trees, cherry trees, perished under the grip of frost. nuts that usually withstand very low temperatures. In Venice the peasants carried their food on foot on the frozen canals. Many rivers froze, including the Po, which was covered by a layer of ice of about 70 centimeters, over which men, chariots and horses passed. Rome and Florence remained isolated due to the intense snowfalls. In the countryside, the cultivation of olive trees, vines and citrus fruits were seriously compromised or destroyed. In many cases the land cultivated before 1709 could no longer be recovered. Even in the Adriatic, as in many other European ports, the frosts blocked the boats, whose crews died of cold and starvation.
In the rest of Europe the situation was even worse. The Thames froze, as did the canals and the port of Amsterdam, while the Baltic Sea remained frozen for four months. An anonymous chronicler of the time tells us that in the Loire Valley, France, “everything that had been sown was completely destroyed. Most of the hens died of cold, and so did the cattle in the stables. The few surviving poultry saw the ridge freeze and fall. Many birds, ducks, partridges, woodcocks and blackbirds, died and were found dead on the roads and on the thick layers of ice and snow. Oaks, ash trees and other lowland trees split in the frost: two thirds of the nuts died. Two thirds of the vines also perished, and among these the oldest ».
Hunger, epidemics and instability
With slight fluctuations, temperatures remained low until spring. But the cold was not the only plague to be faced: the frost was followed by hunger, floods and epidemics. The snow that had accumulated in the winter months caused intense floods when it melted and the epidemics were not long in coming. Broncho-pulmonary diseases increased and spread. The cold and hunger favored the spread of the flu, which had erupted in Rome the previous year, to the point of making it a pandemic that would spread to almost all of Europe between 1709 and 1710. Furthermore, from the Ottoman Empire the plague came.
The famine that followed was dramatic. The terrible cold spells had left a desolate landscape in the countryside, destroying most of the crops. Food was scarce in the cities, because food was no longer arriving from the countryside. This crisis consequently led to an increase in the price of wheat and basic necessities.
The difficult situation of survival also generated episodes of violence. The peasants gathered in gangs to storm the bakeries or attack the convoys of grain bound for the city. Authorities in some states tried to react to the dramatic situation. In France, Louis XIV arranged for the free distribution of bread and forced the aristocracy to open charity canteens. He lowered the price of bread and ordered that the quantity of grain owned be declared. In London, Queen Anne Stuart ordered the purchase of coal which she then distributed to the population. A period of high mortality and low birth rate began. It is difficult to measure the exact number of deaths. In January alone, Paris recorded 24,000 deaths. It is agreed that the exceptional cold and famine of that year caused an unprecedented number of victims: it is estimated that about one million people died out of a total of 22 million inhabitants.