What are the Types of Earth’s Rarest Clouds? Why some clouds are so rare and how are they formed?
1. Asperitas Clouds
Asperitas clouds are very rare clouds which, in human history, have seen only four times. So naturally this question arises that why is it so rare? To understand this, first we discuss the model of their formation. Gravity waves and wind play the biggest role in the formation. Here gravity waves should not be confused with gravitational waves because when we talk about gravitational waves, we are talking about waves in the space-time fabric. When any obstacle like mountains comes in front of the air flowing in the atmosphere, then the waves formed by it are called gravity waves.
Formation of Asperitas Clouds:
Let’s try to understand how aspiring clouds are formed from gravity waves. For the sake of understanding just imagine, there are two points A and point B and the wind has to travel from A to B. If we put a mountain between the path, what will happen? Certainly on the peak of the mountain, where there is a collision of air, that air will create turbulence ahead of the mountain. As we experience when an airplane passes through clouds, the collision of its wings creates a turbulence and because of this, we see clouds there. And something similar happens in our mountain case as well. After which the air coming from behind starts passing over this turbulence and this air forms a very brilliant motion which looks brilliant, at that time, there should be clouds in that region for the formation of Asperitas.
Are the Aircrafts safe from Asperitas Clouds? Is there any danger from Asperitas Clouds presence?
Yes! Generally we do not face any danger from Asperitas because they fly around 6000 feet and our commercial aircraft fly between 31000-38000 feet and they are not exposed to these clouds. Although due to the density being 10 times more than that of a normal cloud, if these clouds are seen during the day, they cause darkness in the day like night. That’s why they look even more scary.
Note: All the discussion is based on a hypothesis which has been published in a research paper, till now no scientist can claim that these clouds exactly form like this because Asperitas are so rare.
2. Anthropogenic Clouds
Anthropogenic clouds are formed due to man made activities like thermal power plants, commercial aircrafts and chemical industries which are obviously polluting clouds and that is why they create a lot of problems. Harmful effects of Anthropogenic clouds are like breathing, itching skin, hair loss and reduction in hair growth and those are genetically transferred to the body i.e. if your father or grand father has taken exposure to these clouds then you will face this problem in future.
3. Roll Clouds
Roll clouds also called The Morning Glory clouds. The name of these clouds gives the idea that something concerns with the morning. These clouds are found at the height of 500 feet above of Asperitas clouds i.e. 6500 feet from Earth surface. Actually, Roll Clouds form in the early morning because due to the cold at night, the air condenses and gets saturated with water. Due to this it forms thunder in the clouds. These formed thunder play important role in cloud formation. Basically, what happens is that due to precipitation, the cold air above the cloud starts coming down and creates pressure on the air traveling from below to above. This pressure increases to such an extent that the warm air does not get any space to travel upwards and that is why the warm air starts traveling upwards from the front of the clouds. And then as soon as this process starts continuously, a roll form of cloud is formed. You can see these clouds mostly in the oceanic region in the months of September and October.
Is there any danger to airplanes and ships while travelling?
If you spot these clouds, it usually means a thunderstorm is on the way. However, if you are flying in an airplane, there is no need to worry because planes travel well above these clouds. But for those on ships or boats, it can be risky, as the storms can affect the ships.
4. Kelvin-Helmholtz clouds
These clouds are spotted at higher altitude around 16500 feet above the Earth surface. It looks like tsunami waves are passing through the sky. These are called Kelvin Helmholtz clouds. These clouds do not only seem swift like tsunami but are equally dangerous because if any airplane enters the clouds then it will have to face massive levels of turbulence. You must have seen ripples being created on water due to air flow. In a similar way these clouds are also formed.
How Kelvin Helmholtz clouds are formed?
Basically these clouds are formed due to two different layers of air in the atmosphere travelling at different velocity. Suppose two airstreams are traveling in opposite direction at different speeds. Then as soon as they move, due to the difference in speed, small wave like disturbances will be created between those two layers. Which will gradually become bigger as the speed of air increases. Due to the crust formed by the lower wave, the air above has very little space left to move forward and that is why the upper air will exert pressure belt on its crust due to which it gets pushed forward and C-shaped bent arc formed. This look likes tsunami like waves moving forward direction. Same pattern can be observed on Jupiter planet. The entire atmosphere is covered with these clouds. Even clouds have been observed on the Sun as well.
5. Lenticular clouds
These clouds are exactly look alike Alien Spaceship. Seeing these, many people got mislead and claimed that they have actually seen aliens. They were mislead actually because this is also a very rare phenomenon which has been seen only 10 to 12 times till now.
Formation of Lenticular Clouds:
Normal air flow takes place on a normally flat surface in such a way that as soon as a mountain or obstacle passes between these clouds, disturbances are created in them and the airflow is disrupted. The air which flows in the downward direction becomes warm and dry because the heat coming from the sun warms the Earth surface as well as the air which is transferred at the surface level and the air which flows in the upward direction cools down due to the higher altitude and keeps on condensing. You can imagine it is cool air, what does the condensation that is happening, actually, cloud formation.
As soon as a cloud forms, a disk shape is formed in it due to the upward and downward air flow and then our lenticular cloud is formed. This process continues so fast that we feel that this lenticular cloud is stationary.
Hazards of Lenticular Clouds:
This cloud looks like a cyclone because of which a sinking effect is created in the surrounding area of the cloud. It appears as if distant bodies are sinking in its part and that is why pilots of powered aircraft avoid flying near this cloud. This cloud is a danger only for the aircraft traveling in its surrounding area, which we can easily avoid.
6. Nacreous clouds
These clouds are also called Mother of Pearl clouds. These clouds look very beautiful and presents awesome panorama meanwhile Nacreous clouds are most dangerous among all and alarming for living beings. Actually, this cloud is an indicator of ozone layer depletion. The crystals in this close-up trigger a chemical reaction between ozone molecules and chlorine and bromine molecules in the atmosphere.
And this reaction is mostly seen in Stratosphere because for this reaction the temperature should be as low as almost -78 degree Celsius and then as soon as atoms are formed in this reaction, it starts destroying ozone molecules i.e. O3 and you want to suffer. A chlorine atom formed due to this cloud has the capability to destroy ozone molecules at once. We the humans are responsible for this ozon depletion who use refrigerator aerosols in our daily routine, due to this every day a huge amount of chlorofluorocarbons i.e. CFC is formed. These CFC release chlorine atoms in the atmosphere and the crystals of the cloud react with these chlorine atoms and the result is ozone layer depletion which is happening everyday. You can say that we are shooting ourselves in the foot because due to these chlorine atoms we may have to face diseases like skin cancer, immune system gets affected and even our brain tissues start getting damaged.
You can also read; How to Make Petrol from Air | How Aircela Machine Works
