Mushroom clouds can only be formed out of explosions occurring in a gravitational field. Without the gravitational force found in the environment, the resulting gas cloud will retain its initial form, which is in the shape of a sphere. As for the nuclear detonation, it is conducted at a certain distance and above the ground to maximize its full impact. After the explosion, a type of cloud called the pyrocumulus is formed immediately. Its name may have been derived from the words “pyro,” meaning fire, and “cumulus,” a name given to thicker clouds in the Earth’s atmosphere. This massive fireball is made up of hot gases that spread outward swiftly. Since the fireball is much hotter and less dense than the air surrounding it, the cloud will begin to rise rapidly. This principle is also the cause behind how a hot-air balloon rises fast and continues to float in the air since it uses hot gas that allows it to rise on the surrounding air that is much colder in temperature. And it is this rising ball of burning gases that eventually forms the mushroom cap.
As the fireball rises, a scientific phenomenon called the Rayleigh–Taylor instability is occurring. The phenomenon happens when two fluids of different densities are merged and then subjected to acceleration. As a result, it propels the lighter fluid upwards. The hotter air would be drawn upwards and into the cloud, similar to how smoke rises from a chimney. In addition, it causes the volume of gases to form the shape of an inverted cup or a funnel. The upward acceleration of the fireball produces very strong air currents known as afterwinds, and these winds will often draw debris from the ground to form what is supposed to be the stem of the mushroom. Once the rising fireball has reached an altitude where its density will be equal to that of the surrounding air, it will begin to disperse, and the debris that it has drawn upward from the ground will then scatter and drift back down. The stabilization point of the cloud will depend upon the features of the atmosphere in the area where it formed, as well as the altitude at which the detonation takes place.
Mushroom clouds would mainly consist of fission materials and debris. The cloud would not be formed out of explosions that take place above the Earth’s surface and even underground. Also, these mushroom clouds are often accompanied by short-lived vapor clouds known as “Wilson clouds,” which is responsible for the ring around the mushroom cap. The Wilson cloud is a result of the low pressure that is created by the negative phase of the shockwaves coming from an explosion, which typically lowers the dew point in the environment, thus triggering the formation of temporary clouds.
What was the largest mushroom cloud ever recorded?
The largest mushroom cloud was caused by the Tsar Bomba, a bomb created by the Soviet Union around 1961 and is considered to be the most powerful nuclear weapon in the history of mankind. The bomb was tested on October 30, 1961, above the Sukhoy Nos (or “Dry Nose”) cape, which is located in Mityushikha Bay, a small bay situated in Russia’s Far North or the Extreme North. It was supposed to be a secret nuclear test for the Soviet Union until US Intelligence agencies detected an abnormal nuclear explosion to the north of Russia using a KC-135R aircraft that is fitted with nuclear-detecting instruments.