Why in the News?

A severe cyclone, Dana, is approaching the Odisha coast. The Indian Meteorological Department (IMD) has predicted strong winds and heavy rainfall. Several districts will be severely affected, and precautionary measures like evacuations and cancellations of services have been implemented.

About Tropical Cyclones

• Formation and Characteristics
  • These are intense storms that form over warm ocean waters.
  • They are known by various names, such as cyclones, hurricanes, typhoons and willy-willies.
• Conditions necessary for formation include
  • Warm ocean temperatures,
  • Coriolis force
  • Minimal vertical wind variations
  • A pre-existing low-pressure are
  • Upper divergence.
• The storm's energy comes from condensation within cumulonimbus clouds.
• Landfall occurs when the cyclone crosses the coast, cutting off moisture supply and causing dissipation.
• Cyclones that recurve after crossing 20° N latitude tend to be more destructive.
• Structure of a Mature Tropical Cyclone
  • Eye: A calm region at the center of the storm.
  • Eye Wall: A ring of towering clouds surrounding the eye, with the strongest winds and heaviest rainfall.
  • Rain Bands: Outer regions of the storm with scattered clouds and rain.
• Impacts of Tropical Cyclones
  • Strong winds can cause widespread damage to structures, trees, and power lines.
  • Heavy rainfall can lead to flooding, landslides, and erosion.
  • Storm surges (rising sea levels) can inundate coastal areas, causing severe damage to property and infrastructure.
  • They can result in significant loss of human life due to injuries, drowning and displacement.
• Mitigation and Response
  • Early warning systems: Monitoring and forecasting tropical cyclones to provide timely alerts to affected populations.
  • Evacuation plans: Preparedness measures to evacuate people from vulnerable areas before landfall.
  • Infrastructure improvements: Building codes and construction practices that can withstand strong winds and flooding.
  • Disaster response teams: Organized efforts to provide relief and assistance to affected areas.