Intense Cyclones on India’s Western Coast
Source: Indian Express
GS II: Environment
Overview of Intense Cyclones on India’s Western Coast
- News in Brief
- Findings in the report
- What are Cyclones?
Why in the News?
According to a new study, Changes in ocean and atmosphere warming are causing more frequent and severe tropical cyclones in the Eastern Arabian Sea, next to India’s west coast.
News in Brief
- The Arabian Sea experiences tropical cyclones during specific times of the year, namely at the start of the southwestern monsoon, between March and June, and after the season, between October and December.
- In 2019, the Arabian Sea witnessed five cyclones, which is higher than the usual count of three.
- This increase was caused by a positive IOD (Indian Ocean dipole) phase during the same year.
- The warming of the Arabian Sea under favourable natural climate modes can intensify and increase the frequency of tropical cyclones in the North Indian Ocean.
- A recent study has highlighted the need for changes in development strategies to account for the dangers posed by more frequent and intense cyclones.
- The North Indian Ocean (NIO) Tropical Cyclone (TC) trends pose significant challenges in forecasting, disaster risk reduction, and humanitarian interventions on the densely populated coasts on the ocean rim.
Cyclones in the Bay of Bengal (BOB) are relatively more frequent and intense than those of the Arabian Sea. This is due to higher sea surface temperatures that the water in the ocean convert to mositure which is important for a cyclone.
Findings in the report
- Indian Ocean Dipole Impact
- The temperature of various parts of the ocean differs, with the sea surface temperature in the western Indian Ocean region increasing during its positive phase, leading to a rise in precipitation.
- This increase in rainfall then spreads to the eastern Indian Ocean, resulting in more rain in that region as well.
- Frequent and Severe Cyclones
- It is a well-known fact that human activities have played a significant role in climate change, resulting in an increase in the frequency and intensity of cyclones.
- Consequently, the densely populated coastal areas along the western coast of India, from Thiruvananthapuram to the coast of Gujarat, are at an increasing risk of the threat of cyclones.
- To mitigate this issue, there is a pressing need to implement new policies and develop technological initiatives that focus on improving storm warning systems, impact-based local weather services, and reliable localized weather services.
- By doing so, these coastal regions can be better prepared and protected from the potential devastation caused by cyclones.
- Coastal Communities Concerns
- Cyclones present a serious danger to both human life and the economy due to their strong winds, heavy rainfall, and storm surges, which can result in loss of life and extensive damage to crops, livestock, and fisheries, resulting in significant economic losses.
- Additionally, cyclones can contribute to the spread of waterborne diseases such as cholera and typhoid fever, having adverse health effects.
What are Cyclones?
- Cyclones are a type of tropical weather system characterized by strong winds and heavy rainfall.
- They are also known as hurricanes or typhoons, depending on the region where they occur.
- Cyclones form over warm ocean waters and can cause significant damage to coastal areas.
- They are classified based on their wind speed, with Category 5 cyclones being the most severe.
- Cyclones can also cause storm surges, which are large waves that can inundate low-lying areas and cause flooding.
Formation of Cyclones
- They are fueled by the heat and moisture from the ocean, which causes the air to rise and form clouds.
- As the air continues to rise, it creates an area of low pressure at the surface.
- This low-pressure area draws in more warm, moist air from the surrounding area, which fuels the cyclone and causes it to spin.
- The rotation of the Earth causes the cyclone to spin
- Counterclockwise in the Northern Hemisphere
- Clockwise in the Southern Hemisphere.
- Cyclones can cause significant damage to coastal areas due to their strong winds and heavy rainfall.
How is a cyclone named?
- Who/Authority: World Meteorological Organisation, United Nations Economic and Social Commission for Asia and the Pacific (WMO/ESCAP) Panel on Tropical Cyclones (PTC).
- Why name Cyclone?
- Avoid confusion if two or more cyclones are occurring simultaneously over the region.
- Naming helps in future reference.
- Who are the member countries? : India, Bangladesh, Myanmar, Pakistan, the Maldives, Oman, Sri Lanka, Thailand, Iran, Qatar, Saudi Arabia, United Arab Emirates and Yemen.
- Naming from the list
- With 8 countries in 2004, there was a list of 64 names eight names from each country.
- In later years the member countries increased to 13 combined releasing 169 names of cyclones with 13 names from each country.
- Conditions for naming :
- Names of the cyclones should be short, simple and easily understood.
- Culturally sensitive or convey any inflammatory meaning.
- India has, so far, proposed the names Gati (speed), Tej (speed), Marasu (musical instrument in Tamil), Aag (fire), Jhar (storm), Ghurni (whirlpool), Vega (speed) and Neer (water).
What is the difference between Cyclone, Hurricane, and Typhoon?
- Depending on its location and strength, a tropical cyclone is referred to by names such as hurricane, tropical storm, cyclonic storm, tropical depression, and simply cyclone.
- A hurricane is a storm that occurs in the Atlantic Ocean and northeastern Pacific Ocean.
- Typhoon occurs in the northwestern Pacific Ocean.
- Cyclone occurs in the South Pacific or Indian Ocean.
Mains Previous Year Question
Q. Tropical cyclones are largely confined to the South China Sea, Bay of Bengal and Gulf of Mexico. Why? (2014)
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