Cyclones, hurricanes, and typhoons are powerful weather phenomena that can cause widespread destruction and loss of life. Despite their different names, these storms are essentially the same weather event, with the only difference being their location. In this comprehensive article, we will explore the science behind these storms, their formation, classification, and impacts on human life and the environment. We will also discuss the importance of early warning systems and preparedness measures to minimize the damage caused by these natural disasters.

What are hurricanes, typhoons and cyclones?

The terms “hurricane,” “typhoon,” and “cyclone” are regional names for tropical cyclones. All tropical cyclones share similar characteristics, such as drawing heat from warm ocean water to power their horizontal, rotating winds. The difference in their names is purely geographic:

• Hurricanes: Hurricanes are tropical cyclones that occur in the Atlantic Ocean and the northeastern Pacific Ocean. They typically develop in the Atlantic basin, affecting the Caribbean, the Gulf of Mexico, and the eastern coastlines of North and Central America. The term “hurricane” is commonly used in the United States to describe these storms.
• Typhoons: Typhoons are tropical cyclones that occur in the northwestern Pacific Ocean. They primarily affect the coastal regions of East and Southeast Asia, including countries such as Japan, China, Taiwan, the Philippines, and Vietnam. The term “typhoon” is commonly used in these areas to refer to these storms.
• Cyclones: Cyclones are tropical cyclones that occur in the Indian Ocean and the southwestern Pacific Ocean. They impact countries such as India, Bangladesh, Australia, and the islands of the Indian and Pacific Oceans. The term “cyclone” is commonly used in these regions to describe these storms. A recent Very Severe Cyclonic Storm (BIPARJOY) over the Northeast Arabian Sea is expected in June.2023

Formation of Tropical Cyclones

Tropical cyclones, also known as hurricanes or typhoons depending on the region, are powerful and organized storm systems that form over warm ocean waters. Here is an overview of the formation process:

1. Warm Ocean Waters: Tropical cyclones require warm ocean waters with temperatures typically above 26.5 degrees Celsius (80 degrees Fahrenheit). The warm waters provide the necessary heat and energy for the storm’s development.
2. Coriolis Effect: The Coriolis effect, caused by the Earth’s rotation, is another critical factor in the formation of tropical cyclones. It helps to create the spin necessary for the storm’s organization. The Coriolis effect is stronger farther away from the equator.
3. Low Atmospheric Pressure: A low-pressure system forms over warm ocean waters due to the rising air. This low-pressure area draws in surrounding air, creating a circulation pattern.
4. Spin and Organization: As the air converges toward the low-pressure centre, it starts to rotate due to the Coriolis effect. This rotation creates a cyclonic or counterclockwise flow in the Northern Hemisphere and an anticyclonic or clockwise flow in the Southern Hemisphere.
5. Vertical Stacking: For a tropical cyclone to strengthen, there should be a vertical stacking of warm, moist air. This allows for the release of latent heat, which further fuels the storm’s intensity.
6. Development of an Eye and Eyewall: As the cyclone intensifies, it develops a well-defined centre called the eye, which is a relatively calm area with clear skies. Surrounding the eye is the eyewall, a ring of intense thunderstorms with the strongest winds and heaviest rainfall.
7. Storm Classification: Depending on the maximum sustained wind speed, tropical cyclones are classified into different categories. The Saffir-Simpson Hurricane Wind Scale is commonly used in the Atlantic and Eastern Pacific basins, ranging from Category 1 (weakest) to Category 5 (strongest).

Tropical cyclones can bring destructive winds, heavy rainfall, storm surges, and flooding, making them dangerous and potentially catastrophic. Meteorological organizations worldwide monitor and track these storms to provide early warnings and help communities prepare and mitigate their impacts.

Classification of Tropical Cyclones

Tropical cyclones, also known as hurricanes or typhoons depending on the region, are classified based on their maximum sustained wind speeds.

The two commonly used classification scales are the Saffir-Simpson Hurricane Wind Scale and the Beaufort Scale. Here is an overview of both scales:

1. Saffir-Simpson Hurricane Wind Scale: 

The Saffir-Simpson Hurricane Wind Scale is primarily used in the Atlantic Ocean and Eastern Pacific Ocean basins. It categorizes tropical cyclones based on their sustained wind speeds and the associated potential for damage. The scale consists of the following categories:

Category 1:

Winds 74-95 mph (64-82 knots). These storms cause minimal damage, primarily to vegetation and unanchored mobile homes.

Category 2:

Winds 96-110 mph (83-95 knots). These storms can cause moderate damage, including damage to roofs, mobile homes, and small trees.

Category 3:

Winds 111-129 mph (96-112 knots). These storms are considered major hurricanes and can cause significant damage, including structural damage to small residences, uprooting of trees, and widespread power outages.

Category 4:

Winds 130-156 mph (113-136 knots). These storms can cause severe damage, including extensive damage to well-built homes, large trees uprooted, and power outages lasting weeks to months.

Category 5:

Winds 157 mph or higher (137 knots or higher). These storms are the most intense and cause catastrophic damage. They can destroy a high percentage of homes, with total roof failure and extensive flooding.

2. Beaufort Scale:

The Beaufort Scale is a more general scale used to estimate wind speeds based on observed conditions at sea or on land. It is not exclusive to tropical cyclones but is often referenced to describe wind strength associated with these storms. The scale ranges from 0 to 12, with corresponding descriptions:

• 0: Calm. Winds less than 1 knot (1 mph).
• 1: Light air. Winds 1-3 knots (1-3 mph).
• 4: Moderate breeze. Winds 11-16 knots (13-18 mph).
• 7: Near Gale. Winds 28-33 knots (32-38 mph).
• 10: Storm. Winds 55-63 knots (63-72 mph).
• 12: Hurricane force. Winds exceeding 64 knots (74 mph).

Both classification scales provide a way to communicate the potential impact and severity of a tropical cyclone based on its wind speeds. However, the Saffir-Simpson Hurricane Wind Scale is specifically designed to categorize and predict the potential damage caused by hurricanes.

Tracking and Forecasting Tropical Cyclones

Meteorologists use satellite imagery, weather radar, and computer models to track and forecast the movement and intensity of tropical cyclones. Early warning systems, such as the National Hurricane Center and the Joint Typhoon Warning Center, provide regular updates on the development and potential impacts of these storms. Accurate forecasting is crucial for issuing timely warnings and allowing communities to prepare for the arrival of a tropical cyclone.

Famous Cyclones, Hurricanes, and Typhoons in World

1. Hurricane Katrina (2005) – One of the most destructive hurricanes in US history, causing catastrophic damage along the Gulf Coast, particularly in New Orleans.
2. Typhoon Haiyan (2013) – The strongest typhoon ever recorded at landfall, Haiyan devastated the Philippines, causing widespread destruction and claiming thousands of lives.
3. Cyclone Nargis (2008) – This devastating cyclone struck Myanmar (formerly Burma), causing a humanitarian crisis with an estimated death toll of over 138,000 people.
4. Hurricane Sandy (2012) – A powerful hurricane that affected the Caribbean and the US East Coast, particularly impacting the New York and New Jersey areas with significant storm surges and flooding.
5. Cyclone Winston (2016) – The strongest tropical cyclone ever recorded in the Southern Hemisphere, Winston tore through Fiji, causing extensive damage and claiming more than 40 lives.
6. The Great Bhola Cyclone of 1970 – Struck East Pakistan (now Bangladesh) and killed between 300,000 to 500,000 people, making it the deadliest tropical cyclone on record.
7. Hurricane Harvey (2017) – This category 4 hurricane made landfall in Texas, causing unprecedented rainfall and catastrophic flooding in the Houston metropolitan area.
8. Super Typhoon Yolanda (Haiyan) (2013) – Known as Typhoon Yolanda in the Philippines, this powerful storm caused widespread devastation, claiming thousands of lives and leaving millions of people displaced.
9. Cyclone Idai (2019) – One of the most destructive tropical cyclones on record in the Southern Hemisphere, Idai struck Mozambique, Zimbabwe, and Malawi, causing catastrophic flooding and a humanitarian crisis.
10. Hurricane Irma (2017) – A powerful category 5 hurricane that affected multiple Caribbean islands and the state of Florida, causing extensive damage and leading to the evacuation of millions of people.
11. Typhoon Bopha (2012) – This typhoon struck the Philippines, causing significant destruction in Mindanao, including flash floods and landslides, resulting in thousands of deaths and widespread damage.

Impacts of Tropical Cyclones

Tropical cyclones can cause widespread destruction due to their strong winds, heavy rainfall, and storm surges. The impacts of these storms can include:

• Structural damage to buildings and infrastructure
• Flooding and landslides
• Loss of life and injury
• Disruption of transportation and communication networks
• Agricultural losses and food shortages
• Economic losses and long-term recovery efforts

Preparedness and Mitigation Measures for Cyclone

To minimize the damage caused by tropical cyclones, communities in at-risk areas must implement preparedness and mitigation measures. These can include:

• Developing and enforcing building codes and land-use planning to reduce vulnerability to storm damage
• Establishing early warning systems and communication networks to provide timely alerts and updates
• Creating evacuation plans and identifying safe shelters for residents
• Stockpiling emergency supplies, such as food, water, and medical supplies
• Conducting public awareness campaigns and education programs to ensure that residents know how to prepare for and respond to tropical cyclones

Climate Change and Tropical Cyclones

Climate change has the potential to impact tropical cyclones, altering their frequency, intensity, and patterns. While the exact nature of these changes is still an active area of research, there are several ways in which climate change can influence tropical cyclones:

1. Increased Sea Surface Temperatures: As global temperatures rise due to climate change, sea surface temperatures also increase. Warm ocean waters provide the fuel for tropical cyclones, so higher temperatures can contribute to more favourable conditions for their formation and intensification.
2. Changes in Atmospheric Moisture: Warmer air holds more moisture, which can result in increased atmospheric moisture content. This can lead to enhanced rainfall rates associated with tropical cyclones, potentially increasing the risk of flooding and precipitation-related impacts.
3. Altered Atmospheric Circulation Patterns: Climate change can affect large-scale atmospheric circulation patterns, such as the strength and position of the jet streams. These changes can influence the steering currents that guide tropical cyclones, potentially altering their tracks and impacting the regions they affect.
4. Changes in Wind Patterns: Climate change can lead to shifts in wind patterns, including changes in wind shear, which refers to the variation of wind speed and direction with altitude. Wind shear plays a crucial role in tropical cyclone development and intensity, so alterations in wind patterns can affect their formation and strength.
5. Rising Sea Levels: Climate change is causing global sea levels to rise due to the melting of ice caps and the expansion of seawater as it warms. Higher sea levels can exacerbate storm surge impacts associated with tropical cyclones, leading to increased coastal flooding and erosion.

While there is scientific consensus that climate change influences the conditions under which tropical cyclones form and develop, there is still ongoing research to understand the precise nature and magnitude of these changes. It’s important to note that attributing individual storms or specific events solely to climate change can be challenging, as tropical cyclones are influenced by various factors. However, it is increasingly recognized that climate change can contribute to the overall risk and impact of tropical cyclones in the long term.

What is a cyclone vs tornado?

A cyclone and a tornado are both powerful weather phenomena characterized by rotating winds. However, there are some key differences between the two:

1. Cyclone: A cyclone is a large-scale weather system that forms over the ocean and is characterized by low atmospheric pressure at its centre. Cyclones are associated with heavy rain, and strong winds, and can span hundreds of kilometres. They rotate counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. Cyclones form over warm ocean waters when atmospheric conditions are favourable, such as low wind shear and high humidity. They typically develop in tropical or subtropical regions and require a large-scale weather system to form.
2. Tornado: A tornado is a violent and localized weather event that forms over land. It is a rapidly rotating column of air that extends from the base of a thunderstorm cloud to the ground. Tornadoes are typically smaller in size compared to cyclones and have a more intense and focused destructive power. Tornadoes form within severe thunderstorms when there is a combination of warm, moist air near the surface and colder air above. The collision of these air masses creates a rotating column of air called a mesocyclone, which can then produce a tornado under certain conditions.

Conclusion

Cyclones, hurricanes, and typhoons are powerful and destructive weather events that pose significant risks to human life and the environment. Understanding the science behind these storms, as well as the importance of preparedness and mitigation measures, is crucial for minimizing their impacts and ensuring the safety and resilience of communities in at-risk areas. As climate change continues to alter the Earth’s weather patterns, ongoing research and adaptation efforts will be essential for addressing the challenges posed by tropical cyclones in the future.