On June 18, 1815, the last major battle of the French Emperor Napoleon I took place on the territory of modern Belgium, which was included in history books as the Battle of Waterloo. The battle was the result of Napoleon's attempt to regain power in France, lost after the war against the coalition of the largest European states and the restoration of the Bourbon dynasty in the country.
Napoleon lost the battle for a number of reasons, the most important of which the researchers of the wars of that era call the prolonged rains that began to flood Europe in May. Even on June 18, it also rained heavily, turning the ground into impenetrable mud, which completely deprived Napoleon's cavalry of mobility and he could not pursue and finish off the enemy troops fleeing from him. But what caused these heavy rains?
On August 21, 2018, the Geology journal published the results of a recent computer simulation, according to which the eruption of the Indonesian volcano Tambora was the cause of the rains in Europe and, as a result, the defeat of Napoleon.
The eruption began on April 5, 1815 and lasted about 4 months, becoming the largest eruption in the documented history of mankind. According to rough estimates, up to 200 cubic kilometers of ash were thrown into the atmosphere, which caused the so-called “year without summer”, described in historical chronicles around the world.
The ash from the eruption reached the stratosphere itself and covered almost the entire planet, causing the global average temperature to drop 5.4 degrees Fahrenheit (3 degrees Celsius) over the next year. Gloomy, cold weather lasted for months in Europe and North America, and 1816 became known as the Year Without Summer.
According to past calculations, it took the volcano many months to affect global weather, since ash particles are not air molecules, they are slowly transported in the atmosphere. However, new research led by Matthew J. Genge, professor in the Department of Geology at Imperial College London in the UK, suggests that this is not the case with volcanic ash.
Erupting large volcanoes can eject ash into the stratosphere, which extends 50 kilometers from the Earth's surface. Further, being dispersed throughout the planet, the ash delays solar radiation and, thereby, affects the global climate.
In addition, gases escaping from the volcano create aerosols in the atmosphere, which also begin to reflect light and have an effect similar to ash on the climate.
Promotional video:
However, if a volcano explodes not just large, but very, very large, the ash it throws out acquires a strong electrical charge. As a result, the ash particles begin to repel each other like two magnets, which are brought together by the same poles. The result is, as Matthew J. Genge writes, the so-called "levitating ash."
Computer simulation based on the measurement of charges of typical volcanic ash shows that "levitating ash" is capable of rising even into the ionosphere, that is, to a height of 80 kilometers or more, forming stable dark clouds there. Moreover, if the eruption is very strong, the charge imparted to the ash particles will be such that the ash will rise to a height of up to 1,000 kilometers!
The movement of streams of the ionosphere is much faster than the movement of air in the underlying layers, therefore, if Tambora began to erupt on April 5, according to the computer model of Matthew J. Genge, Europe should have felt the climate change no later than 2 weeks later. Naturally, Tambora was also to blame for the rains that fell on Waterloo.
To test his model, Matthew J. Genge retrieved the climate records of 1883, when the Krakatoa volcano erupted, comparable in strength to the eruption of Tambor. And as it turned out, the model works great, because 2 weeks after the eruption of Krakatoa, Europe was flooded with long-term precipitation. Thus, concludes Matthew J. Genge, the reason for Napoleon's defeat was not the general genius of the generals from the coalition, but the eruption of a volcano located 13,000 kilometers from France.
A comment
Although the research of Mr. Matthew J. Genge is interesting in itself, which was the reason for this translation, however, in addition to highlighting the old historical facts, the computer model of Matthew J. Genge has quite practical applications.
Now we know for sure that if Yellowstone "blows" in Europe for two months, it will be a terrible rain. The rains will begin about two weeks after the eruption and - in the most optimistic case.
In the most pessimistic case in Europe, it will not rain, but snow, and not snow from water, but snow from nitrogen and oxygen. Therefore, we, like everyone else, hope only for an optimistic development of events.