Cyclone Dana, a cyclonic storm named by Qatar meaning “generosity” in Arabic, is approaching coastal Odisha with expected heavy rains and strong winds. Cyclones, caused by rapid air circulation around low-pressure zones, are classified as tropical and extra-tropical, each carrying unique risks and impacts.
About Cyclones
Cyclones are rapid inward air circulation around a low-pressure area.
The air circulates in an anticlockwise direction in the Northern hemisphere and clockwise in the Southern hemisphere.
Classification
- There are two types of cyclones:
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- Tropical cyclones
- Extra Tropical cyclones (also called Temperate cyclones or middle latitude cyclones or Frontal cyclones or Wave Cyclones).
Tropical Cyclones
- Tropical cyclones are violent storms that originate over oceans in tropical areas and move over to the coastal areas bringing about large scale destruction caused by violent winds, very heavy rainfall and storm surges.
- Tropical Cyclones are one of the most devastating natural calamities in the world.
- Tropical cyclones originate and intensify over warm tropical oceans.
- 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 air divergence above the sea level system.
How Cyclones Are Named?
Background on Naming Cyclones
- In 2000, a group of nations under WMO/ESCAP (World Meteorological Organisation/United Nations Economic and Social Commission for Asia and the Pacific) initiated the process of naming cyclones in the region.
- The initial member countries included Bangladesh, India, the Maldives, Myanmar, Oman, Pakistan, Sri Lanka, and Thailand.
- After suggestions were collected from each member country, the WMO/ESCAP Panel on Tropical Cyclones (PTC) finalized the list of names.
- In 2018, the group expanded to include five more countries: Iran, Qatar, Saudi Arabia, United Arab Emirates, and Yemen.
- In April 2020, the India Meteorological Department (IMD) released a list of 169 cyclone names, with each of the 13 member countries providing 13 names.
Importance of Naming Cyclones
- Names make it easier for people to remember cyclones.
- They help to identify individual cyclones, create awareness about their development, and disseminate warnings quickly.
- Naming cyclones enhances community preparedness and reduces confusion, especially when multiple cyclonic systems are present in a region.
Guidelines for Adopting Cyclone Names
- Proposed names should be:
- Neutral to politics, political figures, religious beliefs, cultures, and gender.
- Not offensive or hurtful to any group globally.
- Short, easy to pronounce, and should not be rude or cruel in nature.
- The name’s maximum length is eight letters.
- The proposal must include the pronunciation and voice-over of the name.
- Once a name is used for a tropical cyclone over the North Indian Ocean, it will not be reused.
The process of naming cyclones aids in public awareness and disaster preparedness, enhancing safety measures for impacted communities. As Cyclone Dana approaches, adherence to precautions and timely communication remain crucial for minimizing potential damage and loss.
