1. CYCLONES AND TROPICAL CYCLONE
| HOW ARE CYCLONES FORMED |
CAUSES AND EFFECTS OF CYCLONES
Class 7 Science
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2. How are cyclones formed |
Causes and effects of cyclones
What is a cyclone?
A cyclone is a system of wind that moves rapidly inward
with a low-pressure area in the middle. In meteorology,
it refers to the large mass of air that surrounds a strong
atmospheric center.The internal winds moving over an
area of low pressure allow us to view the storm in a spiral
shape.The large-scale (synoptic scale) polar vortex and
extra-tropical cyclones are the largest low-pressure
systems.The synchronous scale also includes tropical
cyclones such as tropical cyclones and subtropical
cyclones.
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3. How are cyclones formed |
Causes and effects of cyclones
How are cyclones formed?
Tropical cyclones form only near the equator, in warm ocean waters. A
cyclone is formed when warm, moist air near the ocean’s surface
rises upward. When air rises away from the ocean’s surface, it
generates a low-pressure zone beneath it. It causes air from higher-
pressure places to travel towards the low-pressure area, warming
the air and causing it to climb above.
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4. How are cyclones formed |
Causes and effects of cyclones
What is a tropical cyclone?
Tropical cyclones are familiar to most people because they occur in tropical
oceans.Cyclones and tornadoes are actually tropical cyclones, but they
have different names that indicate where the storm is occurring.
Tropical cyclones only form in warm ocean waters near the equator.
A hurricane forms when warm, humid air rises above the surface of the
ocean.As the air rises above and above the ocean surface, it creates an
area of low pressure. This causes air to move from areas of high pressure
to areas of low pressure, causing the air to heat up and rise.
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5. How are cyclones formed |
Causes and effects of cyclones
When warm and humid air rises and cools, the water in the air turns into
clouds.As ocean heat and water evaporate from the surface of the
ocean, the entire system of clouds and winds rotates and rises. As the air
system spins at increasing speed, an eye forms in the middle. The center
of the storm is very calm and clear.The difference in temperature
between the warm and rising atmosphere causes the air to rise up and
become more energetic. When the wind speed is 39 mph (63 km/h), it
is called a “tropical storm”.
When wind speeds reach 74 mph (119 km/h), the storm is officially called a
“tropical cyclone” or hurricane. Every year 70 to 90 hurricane systems
develop around the world.The Coriolis force causes air to spiral in a
region of low pressure.
Typically, cyclones occur in the Atlantic and Northeast Pacific, while they
occur in the Northeast Pacific.We can define tropical cyclones on the
basis of their wind rate. Cyclones are classified according to wind speed
and the damage they cause.
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6. How are cyclones formed |
Causes and effects of cyclones
 Category 1:Wind speed between 90 and 125 kmph, with some
damage to buildings and trees.
 Category II: Wind speed 125 to 164 kmph, habitat damage,
significant crop, and forest damage.
 Category III: Wind speed 165224 kmph, Structural damage to homes,
extensive damage to plants and uprooted trees, repaired cars,
building damage.
 Category IV: Wind speed between 225 and 279 kilometers per hour,
with power outages and significant damage to cities and towns.
 CategoryV: Wind speed greater than 280 kmph, with extensive
damage.
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7. How are cyclones formed |
Causes and effects of cyclones
PolarCyclone
Cyclones are common in the polar regions of Greenland, Siberia, and
Antarctica. Polar winds are heavier than tropical cyclones in
winter.As you can see, these storm travelers love good weather!
In areas of the field, they are not very common and occur only
very rarely, which is why the damage they do is minimal.
Mesocyclone
The mesocyclone gradually moves into a vortex as part of the
lightning cloud begins to spin.The ‘center’ refers to the ‘meso’,
which we can consider as the midpoint between one climatic
form and another.All storms are thunderstorms, but not all parts
of the thunderstorm are caused by cyclones.
Part of that cloud turns into a storm, even if you can’t actually see it
happening, it’s an intermediate or ‘meso’ step from a normal
cloud to a dangerous spinning cloud moving to the ground.
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8. How are cyclones formed |
Causes and effects of cyclones
What are the causes and effects of cyclones?
 Tropical cyclones cause heavy rainfall and landslides.They cause
serious damage to towns and villages. In addition, they destroy
coastal companies such as shipyards and oil wells.
 When these storms blow in the distance, they cause great
damage to human settlements.
 They destroy a lot of crops and a lot of forests.
 They disturb the entire civilian life, especially when they hit the
power and telephone lines.
 These cyclones often cause tornadoes, which can lead
toflooding.
 They cause great damage not only to property but also to the
lives of the people.Civil institutions are being demolished
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9. How are cyclones formed |
Causes and effects of cyclones
What are the local names of cyclones?
 Typhoons – China Sea
 TropicalCyclones – Indian Ocean
 Hurricanes -Caribbean Sea
 Tornadoes-USA
 WilyWillies – Northern Australia
 Baguio- Philippines
 Taifu- Japan
What are the Cyclone prone areas in India?
India is prone to natural calamities like earthquakes, floods, droughts,
cyclones and landslides. According to the Meteorological Department,
there are 13 coastal states and UnionTerritories of India prone to
cyclones.The four states at risk areWest Bengal, Andhra Pradesh,
Odisha,Tamil Nadu, and one union territory on the east coast,
Pondicherry, and one on the west coast, Gujarat.
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10. How are cyclones formed |
Causes and effects of cyclones
What is the cyclone warning system in India?
The Meteorological Department of India is the nodal agency in India
responsible for weather monitoring, weather forecasting, and
seismology.The CycloneWarning Center (ACWC) predicts a storm area
in the Bay of Bengal and the CycloneWarning Center (CWC) in the
Arabian Sea.The ACWC andCWC sent their reports to the coordinating
center, National CycloneWarningCenter (NCWC).
Every year, Cyclones transmit energy equivalent to several megatons of
nuclear bombs from the ocean into the atmosphere. Every year 70 to 90
hurricane systems develop around the world. Cyclonic systems do not
develop in this region because the Coriolis force is low between latitudes
5degrees north and 5degress south at the equator.
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