Since childhood, it’s my hobby to observe the sky and the clouds. It is mesmerising how the clouds form different shapes and patterns in the blue sky. I remember how I used to argue with my friends upon seeing a particular shape. But, not everyone can see the same shape of any clouds. Apart from that, have you ever wondered how such shapes of clouds are formed?
Cloud is a bunch of lightweight water vapours that are literally floating in the sky! Solar heating, cyclonic or wind circulation lifts water vapours up to the homosphere. The troposphere, stratosphere and mesosphere are together referred to as ‘Earth’s homosphere’. The temperature of the atmosphere starts reducing from mesosphere as we go upwards from the earth’s surface. Due to the low temperature in the homosphere, water freezes at its dew point, and droplets are formed. These droplets are condensed to form clouds.
The bunch of water vapor, droplets and ice crystals are called as ‘cloud’. Due to the wind present in the upper sky, clouds run in a horizontal direction. Clouds are classified depending on their size and density as shown in Fig. 1. Clouds are classified into low (below ~1,900m), middle (between ~1,900m to ~6,000m) and high (above ~6,000m to ~12,000+m) as per their altitude. Low clouds contain cumulus, stratocumulus and stratus clouds. Middle clouds consist of altocumulus and altostratus whereas high clouds include cirrus, cirrocumulus, and cirrostratus as shown in image 2.
When the weight of cloud becomes heavier than air, they fall on the earth in the form of rain or snowfall. Amount of rainfall varies everywhere depending on the environmental conditions. Cloudburst, is the infrequent natural disastrous phenomenon, occurs due to the extreme amount of precipitation in a short period of time. When air mass from low elevation is forced to high elevation the warm air parcel gets mixed with cooler air parcel. This sudden condensation causes heavy and rapid rainfall with thunder and lightning. Cloudburst occurred in Uttarakhand, India in 2013 damaged around 4,500 villages and more than 5000 people lost their lives. The frequency of irregular incidences of heavy or no rainfall has increased recently due to encroachment of people on natural resources for development leading to climate change.
As the earth has clouds of water, other planets also have clouds. But these are not necessarily only of water, but of methane, sulphur dioxide, or any other compound depending on the planetary properties. Clouds are spread from meters to kilometers in all directions. Next time you see the cloud, make sure to inspect and attempt to identify what type of cloud is that (Refer Fig. 1 for comparison)!
Edited by: Anomitra Dey