Cloud comes

Our country has been blessed with diverse climatic conditions. When people living up in the north may be having endless rains, others living in rainless tracts of Thar, Cholistan and part of Balochistan that are situated at the tail end of monsoon regions may be looking at the skies as if petitioning for clouds to appear.

Clouds are essential atmospheric components of the life supporting water cycle, producing the rain and snow that return water to the earth’s surface. They are a permanent feature of the earth’s atmosphere. The atmosphere contains a mixture of invisible gases, primarily nitrogen and oxygen. A small portion of the mixture is always water vapours, although the amount varies widely. Clouds may not be visible but they are present even in apparently rainless and dry expanses.

The natural process of cloud formation is very complex. Simply put, clouds are formed when air moves upward in the atmosphere when the sun warms up the earth’s surface. Air may move up for many other natural reasons as well. The cooling occurs when rising air comes across lower air pressures at higher altitudes and thus expands. Continued cooling eventually causes saturation after which the condensation of water vapours to cloud droplets begins. Tiny water droplets in the atmosphere are seen in different forms. Water vapours are the only atmospheric component that can change its state from a gas to a liquid or solid under temperature and pressure conditions that occur naturally in the atmosphere.

When cooled sufficiently, the invisible water vapour change into a visible appearance, water droplets or ice crystals, thus forming clouds and or fog. The vapours also become visible in the shape of clouds when they interact with rays of light coming from the sun. Ice crystals collide with each other or with droplets that freeze on them, causing further enlargement, sometime thunderstorm or lightening. When the drops cling together and get heavy enough, they fall to earth as rain or snow, or sometimes hail storm.

Each cloud variant has individual properties that characterize the environment in which it forms. On very windy days, the fair weather clouds may be torn and sprinkled, while calmer days produce the classic cotton puffs that look as if they are hanging motionless in the sky. Strong winds at higher altitudes can cause cloud tops to tip as compared to their bases. Wave patterns may even form on cloud tops or in bands of clouds as the air moves up and down in its travels. Often such patterns can be seen in air crossing mountains or similar topographical features. Those who have traveled by air above the clouds may have seen this awe-inspiring phenomenon. Other forms are thin, rain, and wispy clouds in widespread, smooth, layered formations.

Besides endless benefits of clouds that sustain life on the earth planet, watching them is fun and may people do it as an active leisure pursuit. When you devote enough time to look at these natural wonders, you do not get tired of seeing the play of sun and clouds. Some are keen photographers of the cloud formations. Similarly, clouds (also monsoon season called as sawan) are part of our literature. Remember the songs based on themes woven around clouds and sawan.

Have you ever had a break from humdrum of life and watched clouds changing seamlessly forms?


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