Major Tropical Cyclone Zones - World | Oxford Student ATLAS: Maps & Tests - UPSC PDF Download

 Page 1


Major Tropical Cyclone Zones
Introduction
Tropical cyclones, also known as hurricanes, typhoons, or cyclones, are powerful
low-pressure systems that originate over warm tropical waters. These weather
phenomena can last for days, even weeks, and have a significant impact on
coastal regions. In this article, we will delve into the intricacies of tropical
cyclones, exploring their formation, characteristics, stages, and more. Whether
you're preparing for the UPSC Civil Service exam or simply interested in
understanding these natural disasters, this guide will provide valuable insights.
Cyclones
Cyclones are low-pressure systems characterized by rapid inward air circulation.
In the Northern Hemisphere, air flows counterclockwise, while in the Southern
Hemisphere, it circulates clockwise. Cyclones are often associated with storms
and inclement weather conditions. The term "Cyclone" originated from the Greek
word "Cyclos," meaning snake coils, coined by Henry Paddington due to the
Page 2


Major Tropical Cyclone Zones
Introduction
Tropical cyclones, also known as hurricanes, typhoons, or cyclones, are powerful
low-pressure systems that originate over warm tropical waters. These weather
phenomena can last for days, even weeks, and have a significant impact on
coastal regions. In this article, we will delve into the intricacies of tropical
cyclones, exploring their formation, characteristics, stages, and more. Whether
you're preparing for the UPSC Civil Service exam or simply interested in
understanding these natural disasters, this guide will provide valuable insights.
Cyclones
Cyclones are low-pressure systems characterized by rapid inward air circulation.
In the Northern Hemisphere, air flows counterclockwise, while in the Southern
Hemisphere, it circulates clockwise. Cyclones are often associated with storms
and inclement weather conditions. The term "Cyclone" originated from the Greek
word "Cyclos," meaning snake coils, coined by Henry Paddington due to the
Major Tropical Cyclone Zones
resemblance of tropical storms to coiled sea serpents in the Bay of Bengal and the
Arabian Sea.
Tropical Cyclones - Concept
The term "Tropical Cyclone" is used by the World Meteorological Organization to
describe weather systems with winds greater than "Gale Force" (minimum of 63
km per hour). These cyclones form over tropical or subtropical oceans and
coalesce into surface wind circulation. They are powerful storms that bring violent
winds, heavy rainfall, and storm surges, making them one of the world's most
destructive natural disasters.
Favorable Conditions for the Formation
Several factors contribute to the formation of tropical cyclones, including:
· Warm water surface temperature above 27°C
· Strong Coriolis force to form a cyclonic vortex
· Minor variations in vertical wind speed
· Existence of a weak low-pressure area or low-level cyclonic circulation
· Higher divergence above the sea-level system
Origin of Tropical Cyclones
Tropical cyclones typically originate over tropical oceans during late summers and
have a thermal origin. The Coriolis effect causes the powerful local convectional
currents to take on a whirling motion, resulting in the formation of cyclones.
These cyclones form and move until they reach a weak place in the trade wind
belt.
Developmental Stages of Tropical Cyclone
The lifecycle of a tropical cyclone can be categorized into three stages:
1. Formation and Initial Development Stage: The transfer of water vapor and
heat from the warm ocean to the overlying air is crucial for the creation and
early development of a cyclonic storm.
2. Mature Stage: As a tropical storm intensifies, powerful thunderstorms
cause the air to rise and spread out horizontally. This creates an "Eye" (low-
pressure center) surrounded by an "Eyewall," characterized by strong
surface winds.
Page 3


Major Tropical Cyclone Zones
Introduction
Tropical cyclones, also known as hurricanes, typhoons, or cyclones, are powerful
low-pressure systems that originate over warm tropical waters. These weather
phenomena can last for days, even weeks, and have a significant impact on
coastal regions. In this article, we will delve into the intricacies of tropical
cyclones, exploring their formation, characteristics, stages, and more. Whether
you're preparing for the UPSC Civil Service exam or simply interested in
understanding these natural disasters, this guide will provide valuable insights.
Cyclones
Cyclones are low-pressure systems characterized by rapid inward air circulation.
In the Northern Hemisphere, air flows counterclockwise, while in the Southern
Hemisphere, it circulates clockwise. Cyclones are often associated with storms
and inclement weather conditions. The term "Cyclone" originated from the Greek
word "Cyclos," meaning snake coils, coined by Henry Paddington due to the
Major Tropical Cyclone Zones
resemblance of tropical storms to coiled sea serpents in the Bay of Bengal and the
Arabian Sea.
Tropical Cyclones - Concept
The term "Tropical Cyclone" is used by the World Meteorological Organization to
describe weather systems with winds greater than "Gale Force" (minimum of 63
km per hour). These cyclones form over tropical or subtropical oceans and
coalesce into surface wind circulation. They are powerful storms that bring violent
winds, heavy rainfall, and storm surges, making them one of the world's most
destructive natural disasters.
Favorable Conditions for the Formation
Several factors contribute to the formation of tropical cyclones, including:
· Warm water surface temperature above 27°C
· Strong Coriolis force to form a cyclonic vortex
· Minor variations in vertical wind speed
· Existence of a weak low-pressure area or low-level cyclonic circulation
· Higher divergence above the sea-level system
Origin of Tropical Cyclones
Tropical cyclones typically originate over tropical oceans during late summers and
have a thermal origin. The Coriolis effect causes the powerful local convectional
currents to take on a whirling motion, resulting in the formation of cyclones.
These cyclones form and move until they reach a weak place in the trade wind
belt.
Developmental Stages of Tropical Cyclone
The lifecycle of a tropical cyclone can be categorized into three stages:
1. Formation and Initial Development Stage: The transfer of water vapor and
heat from the warm ocean to the overlying air is crucial for the creation and
early development of a cyclonic storm.
2. Mature Stage: As a tropical storm intensifies, powerful thunderstorms
cause the air to rise and spread out horizontally. This creates an "Eye" (low-
pressure center) surrounded by an "Eyewall," characterized by strong
surface winds.
Major Tropical Cyclone Zones
3. Modification and Decay: When the source of warm moist air diminishes,
tropical cyclones start to weaken, losing core low pressure, internal
warmth, and speed. This occurs when they reach land or cooler waters.
Structure of a Tropical Cyclone
A tropical cyclone comprises distinct parts:
· Eye: The central area of the cyclone characterized by calm winds, clear
skies, and relatively low pressure. The eye is typically circular and ranges in
size from a few kilometers to tens of kilometers.
· Eyewall: Surrounding the eye is the eyewall, which is the region of most
intense winds and heaviest rainfall in the cyclone. The eyewall is where the
strongest convection occurs and is associated with severe weather
conditions.
· Rainbands: Spiral bands of clouds and thunderstorms extend outward from
the eyewall. These rainbands can produce heavy rainfall and gusty winds,
contributing to the overall impact of the cyclone.
· Outflow: Above the cyclone, there is an upper-level outflow of air. This
outflow is essential for maintaining the cyclone's circulation and preventing
it from weakening.
Vertical Structure of a Tropical Cyclone
The vertical structure of a tropical cyclone consists of different layers:
· Low-Level Layer: This layer extends from the surface up to a few kilometers
and is characterized by inflow of moist air towards the center of the
cyclone.
· Mid-Level Layer: Above the low-level layer, there is a layer of rising air that
fuels the development and intensification of the cyclone. This layer is
associated with the formation of the eyewall and the release of latent heat.
· Upper-Level Layer: At the upper levels of the cyclone, there is an outflow of
air, which allows for the removal of excess heat and helps maintain the
cyclone's structure. Strong vertical wind shear in this layer can weaken or
disrupt the cyclone.
Favorite Breeding Grounds
Tropical cyclones have specific regions where they tend to form and intensify.
Page 4


Major Tropical Cyclone Zones
Introduction
Tropical cyclones, also known as hurricanes, typhoons, or cyclones, are powerful
low-pressure systems that originate over warm tropical waters. These weather
phenomena can last for days, even weeks, and have a significant impact on
coastal regions. In this article, we will delve into the intricacies of tropical
cyclones, exploring their formation, characteristics, stages, and more. Whether
you're preparing for the UPSC Civil Service exam or simply interested in
understanding these natural disasters, this guide will provide valuable insights.
Cyclones
Cyclones are low-pressure systems characterized by rapid inward air circulation.
In the Northern Hemisphere, air flows counterclockwise, while in the Southern
Hemisphere, it circulates clockwise. Cyclones are often associated with storms
and inclement weather conditions. The term "Cyclone" originated from the Greek
word "Cyclos," meaning snake coils, coined by Henry Paddington due to the
Major Tropical Cyclone Zones
resemblance of tropical storms to coiled sea serpents in the Bay of Bengal and the
Arabian Sea.
Tropical Cyclones - Concept
The term "Tropical Cyclone" is used by the World Meteorological Organization to
describe weather systems with winds greater than "Gale Force" (minimum of 63
km per hour). These cyclones form over tropical or subtropical oceans and
coalesce into surface wind circulation. They are powerful storms that bring violent
winds, heavy rainfall, and storm surges, making them one of the world's most
destructive natural disasters.
Favorable Conditions for the Formation
Several factors contribute to the formation of tropical cyclones, including:
· Warm water surface temperature above 27°C
· Strong Coriolis force to form a cyclonic vortex
· Minor variations in vertical wind speed
· Existence of a weak low-pressure area or low-level cyclonic circulation
· Higher divergence above the sea-level system
Origin of Tropical Cyclones
Tropical cyclones typically originate over tropical oceans during late summers and
have a thermal origin. The Coriolis effect causes the powerful local convectional
currents to take on a whirling motion, resulting in the formation of cyclones.
These cyclones form and move until they reach a weak place in the trade wind
belt.
Developmental Stages of Tropical Cyclone
The lifecycle of a tropical cyclone can be categorized into three stages:
1. Formation and Initial Development Stage: The transfer of water vapor and
heat from the warm ocean to the overlying air is crucial for the creation and
early development of a cyclonic storm.
2. Mature Stage: As a tropical storm intensifies, powerful thunderstorms
cause the air to rise and spread out horizontally. This creates an "Eye" (low-
pressure center) surrounded by an "Eyewall," characterized by strong
surface winds.
Major Tropical Cyclone Zones
3. Modification and Decay: When the source of warm moist air diminishes,
tropical cyclones start to weaken, losing core low pressure, internal
warmth, and speed. This occurs when they reach land or cooler waters.
Structure of a Tropical Cyclone
A tropical cyclone comprises distinct parts:
· Eye: The central area of the cyclone characterized by calm winds, clear
skies, and relatively low pressure. The eye is typically circular and ranges in
size from a few kilometers to tens of kilometers.
· Eyewall: Surrounding the eye is the eyewall, which is the region of most
intense winds and heaviest rainfall in the cyclone. The eyewall is where the
strongest convection occurs and is associated with severe weather
conditions.
· Rainbands: Spiral bands of clouds and thunderstorms extend outward from
the eyewall. These rainbands can produce heavy rainfall and gusty winds,
contributing to the overall impact of the cyclone.
· Outflow: Above the cyclone, there is an upper-level outflow of air. This
outflow is essential for maintaining the cyclone's circulation and preventing
it from weakening.
Vertical Structure of a Tropical Cyclone
The vertical structure of a tropical cyclone consists of different layers:
· Low-Level Layer: This layer extends from the surface up to a few kilometers
and is characterized by inflow of moist air towards the center of the
cyclone.
· Mid-Level Layer: Above the low-level layer, there is a layer of rising air that
fuels the development and intensification of the cyclone. This layer is
associated with the formation of the eyewall and the release of latent heat.
· Upper-Level Layer: At the upper levels of the cyclone, there is an outflow of
air, which allows for the removal of excess heat and helps maintain the
cyclone's structure. Strong vertical wind shear in this layer can weaken or
disrupt the cyclone.
Favorite Breeding Grounds
Tropical cyclones have specific regions where they tend to form and intensify.
Major Tropical Cyclone Zones
These regions are known as the "breeding grounds" of tropical cyclones. Some of
the favorite breeding grounds include:
· Atlantic Basin: The tropical and subtropical regions of the Atlantic Ocean,
Caribbean Sea, and Gulf of Mexico.
· Eastern Pacific Basin: The eastern portion of the Pacific Ocean, from the
coast of Central America to the west coast of Mexico.
· Western Pacific Basin: The western portion of the Pacific Ocean, including
the Philippine Sea and the South China Sea.
· Indian Ocean: The Bay of Bengal and the Arabian Sea are prime locations
for the formation of tropical cyclones.
Local Names of Tropical Cyclones
In different regions of the world, tropical cyclones are given local names to aid in
identification and communication. For example:
· North Atlantic and Northeast Pacific: Hurricanes
· Northwest Pacific: Typhoons
· South Pacific and Indian Ocean: Cyclones
Characteristics of Temperate Cyclones
Temperate cyclones, also known as extratropical cyclones or mid-latitude
cyclones, differ from tropical cyclones in several ways. Some of their
characteristics include:
· Formation: Temperate cyclones form in the middle latitudes, away from
the equator, and are associated with the clash of warm and cold air masses.
· Fronts: These cyclones are often accompanied by fronts, which are
boundaries between different air masses. Common fronts include cold
fronts, warm fronts, and occluded fronts.
· Duration: Temperate cyclones tend to last for shorter durations compared
to tropical cyclones.
· Impact: While tropical cyclones primarily affect coastal regions, temperate
cyclones can impact a larger area, including continental interiors.
Warning of Tropical Cyclone
To mitigate the potential damage caused by tropical cyclones, timely warnings
and forecasts are crucial. Meteorological agencies around the world employ
various methods to issue cyclone warnings, including:
Page 5


Major Tropical Cyclone Zones
Introduction
Tropical cyclones, also known as hurricanes, typhoons, or cyclones, are powerful
low-pressure systems that originate over warm tropical waters. These weather
phenomena can last for days, even weeks, and have a significant impact on
coastal regions. In this article, we will delve into the intricacies of tropical
cyclones, exploring their formation, characteristics, stages, and more. Whether
you're preparing for the UPSC Civil Service exam or simply interested in
understanding these natural disasters, this guide will provide valuable insights.
Cyclones
Cyclones are low-pressure systems characterized by rapid inward air circulation.
In the Northern Hemisphere, air flows counterclockwise, while in the Southern
Hemisphere, it circulates clockwise. Cyclones are often associated with storms
and inclement weather conditions. The term "Cyclone" originated from the Greek
word "Cyclos," meaning snake coils, coined by Henry Paddington due to the
Major Tropical Cyclone Zones
resemblance of tropical storms to coiled sea serpents in the Bay of Bengal and the
Arabian Sea.
Tropical Cyclones - Concept
The term "Tropical Cyclone" is used by the World Meteorological Organization to
describe weather systems with winds greater than "Gale Force" (minimum of 63
km per hour). These cyclones form over tropical or subtropical oceans and
coalesce into surface wind circulation. They are powerful storms that bring violent
winds, heavy rainfall, and storm surges, making them one of the world's most
destructive natural disasters.
Favorable Conditions for the Formation
Several factors contribute to the formation of tropical cyclones, including:
· Warm water surface temperature above 27°C
· Strong Coriolis force to form a cyclonic vortex
· Minor variations in vertical wind speed
· Existence of a weak low-pressure area or low-level cyclonic circulation
· Higher divergence above the sea-level system
Origin of Tropical Cyclones
Tropical cyclones typically originate over tropical oceans during late summers and
have a thermal origin. The Coriolis effect causes the powerful local convectional
currents to take on a whirling motion, resulting in the formation of cyclones.
These cyclones form and move until they reach a weak place in the trade wind
belt.
Developmental Stages of Tropical Cyclone
The lifecycle of a tropical cyclone can be categorized into three stages:
1. Formation and Initial Development Stage: The transfer of water vapor and
heat from the warm ocean to the overlying air is crucial for the creation and
early development of a cyclonic storm.
2. Mature Stage: As a tropical storm intensifies, powerful thunderstorms
cause the air to rise and spread out horizontally. This creates an "Eye" (low-
pressure center) surrounded by an "Eyewall," characterized by strong
surface winds.
Major Tropical Cyclone Zones
3. Modification and Decay: When the source of warm moist air diminishes,
tropical cyclones start to weaken, losing core low pressure, internal
warmth, and speed. This occurs when they reach land or cooler waters.
Structure of a Tropical Cyclone
A tropical cyclone comprises distinct parts:
· Eye: The central area of the cyclone characterized by calm winds, clear
skies, and relatively low pressure. The eye is typically circular and ranges in
size from a few kilometers to tens of kilometers.
· Eyewall: Surrounding the eye is the eyewall, which is the region of most
intense winds and heaviest rainfall in the cyclone. The eyewall is where the
strongest convection occurs and is associated with severe weather
conditions.
· Rainbands: Spiral bands of clouds and thunderstorms extend outward from
the eyewall. These rainbands can produce heavy rainfall and gusty winds,
contributing to the overall impact of the cyclone.
· Outflow: Above the cyclone, there is an upper-level outflow of air. This
outflow is essential for maintaining the cyclone's circulation and preventing
it from weakening.
Vertical Structure of a Tropical Cyclone
The vertical structure of a tropical cyclone consists of different layers:
· Low-Level Layer: This layer extends from the surface up to a few kilometers
and is characterized by inflow of moist air towards the center of the
cyclone.
· Mid-Level Layer: Above the low-level layer, there is a layer of rising air that
fuels the development and intensification of the cyclone. This layer is
associated with the formation of the eyewall and the release of latent heat.
· Upper-Level Layer: At the upper levels of the cyclone, there is an outflow of
air, which allows for the removal of excess heat and helps maintain the
cyclone's structure. Strong vertical wind shear in this layer can weaken or
disrupt the cyclone.
Favorite Breeding Grounds
Tropical cyclones have specific regions where they tend to form and intensify.
Major Tropical Cyclone Zones
These regions are known as the "breeding grounds" of tropical cyclones. Some of
the favorite breeding grounds include:
· Atlantic Basin: The tropical and subtropical regions of the Atlantic Ocean,
Caribbean Sea, and Gulf of Mexico.
· Eastern Pacific Basin: The eastern portion of the Pacific Ocean, from the
coast of Central America to the west coast of Mexico.
· Western Pacific Basin: The western portion of the Pacific Ocean, including
the Philippine Sea and the South China Sea.
· Indian Ocean: The Bay of Bengal and the Arabian Sea are prime locations
for the formation of tropical cyclones.
Local Names of Tropical Cyclones
In different regions of the world, tropical cyclones are given local names to aid in
identification and communication. For example:
· North Atlantic and Northeast Pacific: Hurricanes
· Northwest Pacific: Typhoons
· South Pacific and Indian Ocean: Cyclones
Characteristics of Temperate Cyclones
Temperate cyclones, also known as extratropical cyclones or mid-latitude
cyclones, differ from tropical cyclones in several ways. Some of their
characteristics include:
· Formation: Temperate cyclones form in the middle latitudes, away from
the equator, and are associated with the clash of warm and cold air masses.
· Fronts: These cyclones are often accompanied by fronts, which are
boundaries between different air masses. Common fronts include cold
fronts, warm fronts, and occluded fronts.
· Duration: Temperate cyclones tend to last for shorter durations compared
to tropical cyclones.
· Impact: While tropical cyclones primarily affect coastal regions, temperate
cyclones can impact a larger area, including continental interiors.
Warning of Tropical Cyclone
To mitigate the potential damage caused by tropical cyclones, timely warnings
and forecasts are crucial. Meteorological agencies around the world employ
various methods to issue cyclone warnings, including:
Major Tropical Cyclone Zones
· Satellite imagery and remote sensing
· Doppler radar observations
· Weather buoys and ships
· Numerical weather prediction models
By monitoring and analyzing data from these sources, meteorologists can track
the development, movement, and intensity of tropical cyclones, providing
valuable information to the public and emergency management authorities.
Significance of Tropical Cyclone
· The global heat balance is influenced by tropical cyclones, which transfer
warm tropical air from the equator to the poles.
· Absence of tropical cyclones would result in increased temperatures in the
tropics and decreased temperatures in the poles.
· These weather systems excel at generating rainfall and thus can effectively
alleviate drought conditions.
Conclusion
While tropical cyclones can have destructive and alarming consequences for
human populations, they can also provide relief during drought conditions.
Additionally, cyclones are not confined to Earth alone; they are observed on other
planets such as Mars, Jupiter, and Neptune.