The water vapor in the air is not visible most of the time. When it collects and condenses, a cloud is the end result. Clouds are actually a product of moisture. This is why the sky is full of clouds when it is raining or snowing. There is a specific process that leads to cloud formation and for this process to be successful certain atmospheric ingredients must be present and brought together.
Atmospheric ingredients are the elements in the atmosphere responsible for cloud formation. When these ingredients come together in the right quantities and the right time, cloud formation occurs. The atmospheric ingredients needed in order for clouds to form include water, pressure or temperature changes and dust particles.
Water is one of the atmospheric ingredients used during cloud formation. In order for water molecules to collect, they must have a surface. Once water molecules collect they mix with the other atmospheric ingredients to form a cloud.
Dust particles are a necessary atmospheric ingredient in cloud formation. Unless relative humidity exceeds 100%, dust particles must be present in order for a cloud to form. This dust can come from a number of sources such as ocean sea spray, volcanoes, fires or cars. Other atmospheric particles can play the role of dust such as bacteria.
Pressure and Temperature Changes
As air pressure or air temperature decreases it causes the air to be able to hold less water. As the temperature decreases, the process of gaseous water condensing into liquid water has a greater chance of happening.
Processes that Cause Cloud Formation
Several different processes can cause clouds to form. They include radiative cooling, convergence, orographic uplift and convectional lifting. Radiative cooling is a process in which the sun stops supplying the air and ground with any solar insolation related derived energy. Convergence is a process in which two masses of air meet. Convectional lifting is a process in which the air at the ground surface is surface heated. Orographic uplift is a process in which the physical presence of elevated land forces the air to rise.
So, the next time you look up at the sky think about the process in which clouds are formed. Think about what they mean and how they came to be.
Pidwirny, M. (2006). Cloud Formation Processes. Fundamentals of Physical Geography, 2nd Edition. Retrieved on May 12, 2010 from Physical Geography: https://www.physicalgeography.net/fundamentals/8e.html
Clouds: leokrol – sxc.hu