How Do Clouds Form

An interesting natural phenomenon, clouds are very helpful in predicting the weather to a certain level. They exist in all planets that have an atmosphere in the solar system. Apart from earth, other planets that have clouds are Venus, Mars, Jupiter and Saturn. Clouds are the outcome of the condensed droplets suspended in the atmosphere above the surface of land or water. Although they can be seen in different shapes and sizes, they all are made up of the same thing - condensed water or ice. There are different types of clouds, the most common being stratus, cirrus and cumulus. Read through the following lines to know how do clouds exactly form.

 

 

The first step in the formation of clouds includes evaporation, transpiration and heating of air. Collectively known as evapotranspiration, evaporation and transpiration are the most vital parts of the hydrologic cycle. When a body of water such as lake or ocean is heated by sun, the water on the surface sublimates and turns into a vapor. This process is called evaporation. Transpiration occurs when plants sweat water through leaves and stems, which then turns into vapors and mixes with the air. Similarly, the soil also vaporizes when exposed to heat and air.

 

When ground and water surfaces get warm, they heat up the air also. Since, hot air is less dense than cool air; the heated air begins to rise into the atmosphere. With the rise in vapor, the atmospheric pressure drops and the vapor begin to expand. This result in cooling of the vapors, which condense or clump together, out of the air. The heat causes the vapors to rise further. The air expands with a drop in pressure at increasing altitudes, which causes it to cool. This cooling causes the air to condense, which results in the formation of liquid droplets.

 

The temperature at which the air begins to condense is called the dewpoint. Dewpoint occurs when the air is saturated at a given temperature and pressure. Eventually, more air condenses to form water, till the air reaches the same temperature as the surrounding atmosphere, or equilibrium temperature. The water vapor that condenses to form enough liquid water to become visible is called a cloud. Clouds can vary in different shapes and types, depending upon how long the cloud rises after reaching the dewpoint i.e., the distance the cloud covers between dewpoint temperature and equilibrium temperature.

 

The air that rises for a longer time after reaching dewpoint will form tall, fluffy cloud, such as a cumulus cloud. On the other hand, the air that reaches equilibrium will result in a flatter, layered cloud, such as a stratus cloud. The colors of the clouds also vary from cloud to cloud. A white cloud means that it is formed with warm air, which contains water vapor. Grey or black clouds are formed when droplets combine to form larger drops. Other colors like blue, green and yellow are formed naturally in the clouds.