Tropical cyclones originate on the oceanic parts and as soon as they reach the terrestrial parts, these storms gradually weakened end Explain with reasons

Tropical cyclones are one of the most powerful and destructive weather systems on Earth. They are known by different names in different parts of the world—hurricanes in the Atlantic Ocean, typhoons in the western Pacific, and cyclones in the Indian Ocean and South Pacific. Despite the different names, their formation process, structure, and behavior remain largely the same.

One of the most interesting facts about tropical cyclones is that they form over warm ocean waters but start to weaken once they reach land. This article explains in simple terms why tropical cyclones originate over oceans and why they die down when they move over land, along with the scientific reasons behind this behavior.

How Do Tropical Cyclones Form?

Tropical cyclones do not appear out of nowhere. Certain conditions must be present for them to develop:

1. Warm Ocean Water

The first and most important requirement for a tropical cyclone to form is warm ocean water, generally with a temperature of at least 26.5°C (80°F).
This warm water acts like fuel for the cyclone. It provides the energy needed for the storm to grow stronger.

2. High Humidity in the Air

Along with warm water, the air above the ocean must also be humid.
When the warm, moist air rises from the ocean surface, it cools and condenses to form clouds. This process releases heat, which further powers the cyclone.

3. Low Pressure Area

Cyclones usually begin in areas where there is low atmospheric pressure.
This low pressure causes air to rush inwards, spinning due to the rotation of the Earth (Coriolis Effect), forming a spiral pattern.

4. Little Wind Shear

Wind shear means a change in wind speed or direction with height.
For a cyclone to grow, wind shear should be low. If wind speeds change too much from the surface to higher levels, it can tear the cyclone apart.

Why Do Cyclones Weaken After Reaching Land?

Once a cyclone reaches land, it begins to lose its strength. This happens due to several key reasons:

1. Loss of Moisture Source (Warm Ocean Water)

As mentioned, the cyclone’s fuel is the warm ocean water.
When the storm moves over land, it can no longer draw moisture and heat from the ocean. This cuts off the energy supply.
As a result, the storm begins to weaken gradually and eventually dies out.

2. Increase in Surface Friction

The ocean is smooth, allowing the storm to spin freely.
Land surfaces are rough, with trees, buildings, hills, and other obstacles.
When the cyclone moves over land, it encounters more friction. This slows down the winds and breaks the organized structure of the cyclone.

3. Dry Air Over Land

Compared to the moist air over the ocean, land air is generally drier.
Dry air enters the cyclone system and causes clouds to evaporate. This reduces the strength of the storm.

4. Terrain and Topography

Mountains, forests, and uneven ground disturb the cyclone’s flow of air.
This causes disruption in the cyclone’s circular motion, leading to weakening and disorganization.

Stages of a Tropical Cyclone

Understanding the life cycle of a tropical cyclone also helps in explaining why it weakens after landfall.

1. Formation Stage

Begins over warm ocean water.
A low-pressure area forms and starts drawing in moist air.
The storm begins to rotate due to Earth's rotation.

2. Maturing Stage

The cyclone becomes stronger.
It can grow in size and wind speed.
This is when the cyclone is most powerful and dangerous.

3. Landfall Stage

The cyclone moves towards the coast and reaches land.
As soon as it hits land, it starts weakening.

4. Dissipation Stage

The storm loses strength quickly.
Rain and wind decrease, and the storm dies out.

Scientific Explanation: Heat Engine Model

Scientists often compare tropical cyclones to a heat engine:

The ocean acts as a fuel tank, providing heat and moisture.
As the warm, moist air rises, it cools and releases heat, which drives the cyclone’s engine.
The more warm water available, the stronger the engine.
When the storm hits land, the fuel is cut off.
Just like a car stops running without fuel, the cyclone weakens without heat and moisture.

Examples of Cyclones Weakening After Landfall

Let us look at a few examples to understand this process better:

Cyclone Amphan (2020)

Formed in the Bay of Bengal.
Became a super cyclone over warm ocean waters.
Lost strength rapidly after it made landfall in West Bengal, India.

Cyclone Fani (2019)

Started in the Indian Ocean and became a very severe cyclone.
After hitting Odisha, it quickly weakened into a depression within a few hours.

Hurricane Katrina (2005)

Devastated parts of the USA.
Lost strength after reaching inland areas away from the Gulf of Mexico.

These examples show how common and predictable the weakening of cyclones over land is.

Why Are Coastal Areas More Vulnerable?

Since tropical cyclones get their energy from oceans, they are strongest near coastal regions. This makes coastal areas highly vulnerable to:

Strong winds
Heavy rainfall
Storm surges (rise in sea level)
Flooding

Therefore, places near the coast need better disaster planning and early warning systems.

Modern Tools to Track Cyclones

Thanks to technology, scientists can now track and predict cyclones better:

Satellites monitor storm formation and movement.
Doppler radars help in observing rainfall and wind speeds.
Computer models are used to forecast the path and intensity of the cyclone.

This information helps governments issue timely warnings and evacuations, saving many lives.

How Can We Prepare for Cyclones?

Although cyclones are natural events, we can reduce their impact through good planning:

1. Early Warning Systems

Accurate weather forecasting helps people evacuate before the storm hits.

2. Stronger Buildings

Coastal houses and structures should be cyclone-resistant.

3. Public Awareness

People should know what to do before, during, and after a cyclone.

4. Coastal Tree Planting

Trees such as mangroves help reduce wind speed and water surges.

To sum up, tropical cyclones are born over warm ocean waters because they need heat and moisture to grow. Once they move over land, they lose access to their energy source, face more friction, encounter dry air, and become disorganized. That is why cyclones always weaken and eventually die out after making landfall.

Understanding this behavior is important for scientists, governments, and communities, especially in cyclone-prone areas. With proper awareness, technology, and planning, we can reduce the damage caused by these powerful storms.