Previously, I used to wonder, ‘Summers are supposed to be dry and hot with scorching Sun, making people soak in their sweat and drink litres of water as an aftermath. But why are some summer quite different, like the one in 2021?’
And today, I have found out the reason for my ‘tell me why’ question! And I shall try to break down the reason behind it in simple parts.
Firstly, let me give you the processes involved in a primitive water cycle studied in our middle schools; evaporation, condensation, and precipitation. And if any of these processes take place in dearth or excess, it could lead to destruction and devastation!
When the temperature of the ocean surface water reaches at least 270C due to solar heating, the warm air above the water rises quickly into the atmosphere, creating an area of low pressure. When the vapours move above the sea level, the amount of gas molecules decreases i.e., the air becomes less dense than the air near the sea level. This is what is meant by ‘thin air’ and as the air gets thinner, it tends to get cooler. As a matter of fact, cooler air can’t hold moisture and so it condenses into a cloud.
As the air rises quickly, warmer and moist air of high pressure around the low-pressure area, spirals further up, and again we have the same cycle. But when the cloud formation is quite alarmingly fast, the rotating, warm air drawn upward creates strong winds subsequently leading to the formation of fierce storms.
Such storm formations are more prominent in the oceans closer to the equator owing to the much warmer ocean surfaces and are called ‘tropical storms’ which are immensely powerful and can travel up to a wind speed of 65 kph (kilometres per hour). When it reaches way high as 119 kph and above, it is referred to as ‘tropical cyclones’ and when it further increases to 155 kph and above, that is when it is referred to as ‘super cyclones’.
A tropical storm
The devastating cyclones experienced by our Indian states are the tropical cyclones originating from the Bay of Bengal, and to name a few- Yaas, Amphan, and Fani. Before continuing further, I would like to pose a question,
‘Why is the Bay of Bengal a hotbed for cyclones?’
There are only 2 reasons. Firstly the winds of the ocean are very, very strong. Secondly, the surface temperature of the waters is high which leads to easy cloud formation.
Coming back, these devastating and destructive tropical cyclones formed in the Bay of Bengal occur during the late summers (April to mid-November) and every year we report one or the other cyclones ravaging India, Bangladesh, Myanmar, and Srilanka. These dangerous cyclones produce destructive winds, heavy rainfall with flooding, and damaging storms. The aftermath is overwhelmingly disastrous. Damaged houses, uprooted trees, disturbed civil facilities, and interrupted communication systems are to name a few.
‘We can’t stop natural disasters but we can arm ourselves with knowledge; so many lives wouldn’t have to be lost if there was enough disaster preparedness.’
Petra Nemcova, Czech model, entrepreneur, and the official UNDRR World Tsunami Awareness Advocate
Certain natural disasters could be avoided by modifying our reckless human activities while some disasters are inevitable. The nation has to cultivate enough disaster preparedness and act per ‘Zero Casualty’ to safeguard the lives of vulnerable classes. At present, the Indian states Orissa and West Bengal are hit by a very severe cyclonic storm, ‘Cyclone Yaas’, and the government of Orissa been exemplary for other nations to be disaster prepared. And tomorrow, I shall come up with a blog talking about the effective disaster preparedness of Orissa!
With the hope that this post would have made you understand the cyclone formation, I shall take my leave, ensuring that tomorrow I shall come up with a post on ‘disaster preparedness’.
Until then, happy reading other blogs!
PHYSICS LOVE 