How and Why Cyclones are Formed

The torrential, unseasonal rains we all saw in the middle of May this year weren’t just a random product of climate change, but due to Cyclone Asani. This cyclone was created in the Bay of Bengal and consequently, brought rains to many parts of the country.

So, how are cyclones created? And how do they spin so fast, causing rain across the country? Let’s have a look.

What is a cyclone?

A cyclone is a system of winds that are rotating inwards to an area of low barometric pressure. Warm air, full of moisture, gathers above the surface of the ocean whenever there is less density in the atmosphere. As this air moves upwards, away from the surface of the ocean, it creates an area of low pressure below.

This area then is filled with high-pressure air that is around it and warms up, once again. This forms a cycle of warm, moist air rising from the water and creating low-pressure areas. Now, this water cycle eventually produces clouds over the water that spin and grow fast thanks to the rapid heating of air and cooling of water.

As this cycle grows faster and the clouds spin faster, a central point of very low-pressure forms in the middle, thus forming a cyclone.

Also read: Strangest Natural Wonders That Look Like They’re Straight Out Of A Movie

What the coriolis?

You may be wondering what makes the clouds and the air above the water spin faster and faster. It’s a phenomenon called the Coriolis force. The Coriolis force is the apparent acceleration of an object that is on or near Earth, due to the Earth’s rotation. While this has many applications in physics, its most important effect is on the wind. The way the wind moves anywhere in the world is affected by the Earth’s rotation and produces a very interesting effect. Any winds blowing toward the equator in the northern hemisphere are moved toward the west, while any winds moving upward toward the equator in the southern hemisphere are deflected to the east. It has the inverse effect on winds blowing from the equator toward either pole.

You may have also heard that the Coriolis effect makes the water going down the drain spin in a clockwise direction in the northern hemisphere and anticlockwise in the southern. This is a topic of debate, even among some physicists. But what is most widely believed is that it is a myth as a drain is too small a space for the Earth’s rotation to affect it.

Also read: After Yaas and Tauktae, the next cyclone will be named Gulab. Do you know why?

Types of cyclones

There are 4 main types of cyclones: Tropical, polar, mesocyclone and extratropical cyclones.

Tropical regions like India experience tropical cyclones like hurricanes and typhoons, which are types of cyclones. Polar cyclones, as the name suggests, take place in the Arctic and Antarctic regions and are difficult to predict as they tend to form within 24 hours. Mesocyclones are super strong thunderstorms, where the air and heat rise on a vertical axis instead of a slanting one that tropical cyclones see. Extratropical cyclones take place in the middle latitudes, which are regions between the Tropic of Cancer and the Arctic Circle, and the Tropic of Capricorn and the Antarctic. Its winds are usually weaker than a tropical cyclone.

The Earth sees about 70-90 cyclonic systems form every year, which is why we have at least one major cyclone annually, just before the monsoons begin. The extreme heat in the summer makes for perfect cyclonic conditions around India. Strong winds carry these cyclonic clouds, and the cyclone itself too, sometimes, towards land. Hence, we experience unseasonal showers even if we’re not close to the coast.

Unfortunately, due to climate change increasing temperatures everywhere, the number of cyclones and cyclonic storms have increased. This has also led to more destruction in coastal areas and longer lasting effects.