Tropical cyclones names

Tropical cyclones names

Subject: Geography

Section: Climatology

Context:

• Cyclone Asani, formed in the Bay of Bengal, is likely to intensify into a severe cyclonic storm in coming days.
• The name ‘Asani’ was given by Sri Lanka. Asani or ‘wrath’ in Sinhalese will be the first cyclonic storm of the season.

Why name cyclones?

• According to the World Meteorological Organisation (WMO), an agency under the United Nations, there can be more than one cyclone at a time in a particular geographical location or around the globe and the systems can last for a week or more.
• Therefore, each tropical storm is given a name to avoid confusion, in facilitating disaster risk awareness, management and mitigation.
• Usually, short and easy-to-pronounce names are helpful in effectively giving out detailed storm information between hundreds of scattered stations, coastal bases and ships at sea. The process also reduced errors.
• In the beginning, storms were named arbitrarily. Later, meteorologists decided to name storms from a list for a more organised and efficient system.
• With Cyclone Asani — a name given by Sri Lanka that means ‘wrath’ in Sinhalese — formed in the Bay of Bengal on Sunday morning and hurtling towards the east coast, the same question pops up again.

How are cyclones named?

• There are six Regional Specialised Meteorological Centres (RSMCs) worldwide and five regional Tropical Cyclone Warning Centres, which are mandated for issuing advisories and naming of cyclonic storms.
• The India Meteorological Department (IMD) is one of the six Regional Specialised Meteorological Centres (RSMCs) that is tasked with giving a title to a cyclone that forms over the northern Indian Ocean when it has reached a maximum sustained surface wind speed of 62 kmph or more.
• The naming of cyclones in the Bay of Bengal and Arabian Sea started in September 2004. The IMD provides cyclone and storm surge advisories to 13 countries across the north Indian Ocean.
• If the storm’s wind speed reaches or crosses this mark, it is then classified into a hurricane/cyclone/typhoon.
• The list is arranged according to the names, given by alphabetically-arranged countries, that are neutral to gender, politics, religious beliefs and cultures. Once a name is used, it will not be repeated again.
• The word, which can have a maximum of eight letters, should not be offensive to any member country or hurt the sentiments of any group of population.
• The most recent list released in 2020 has 169 names, including 13 names each from 13 countries. Earlier, eight countries had given 64 names.
• Names from India that have been used include Gati (speed), Megh (cloud), Akash (sky). Other designations that have been used earlier included Ogni, Helen and Fani from Bangladesh; and Laila, Nargis and Bulbul from Pakistan.
• The cyclone that will form after Asani will be called Sitrang, a name given by Thailand. Earlier, WMO had retired ‘Ida’ from the future list of names as the storm was a destructive and deadly hurricane.
• Regardless of the name, the intensity of cyclones varies. For instance, Cyclone Gulab made landfall in September 2021, splashing heavy rains along with strong winds over north coastal Andhra Pradesh and adjoining south coastal Odisha, before weakening into a deep depression. But Cyclone Amphan that made landfall in May 2020 left as many as 80 people dead and caused havoc in parts of Odisha and West Bengal.

What are tropical cyclones?

• A tropical cyclone is an intense circular storm that originates over warm tropical oceans and is characterized by low atmospheric pressure, high winds, and heavy rain.
• A characteristic feature of tropical cyclones is the eye, a central region of clear skies, warm temperatures, and low atmospheric pressure.
• Storms of this type are called hurricanes in the North Atlantic and eastern Pacific and typhoons in South-East Asia and China. They are called tropical cyclones in the southwest Pacific and Indian Ocean region and Willy-willies in north-western
• Storms rotate counter-clockwise in the northern hemisphere and clockwise in the southern
• The conditions favourable for the formation and intensification of tropical storms are:
  • Large sea surface with temperature higher than 27° C.
  • Presence of the Coriolis force.
  • Small variations in the vertical wind speed.
  • A pre-existing weak low-pressure area or low-level-cyclonic circulation.
  • Upper divergence above the sea level system.