What is cyclone :

  • A cycloneis basically a large air mass that rotates around a strong center of low atmospheric pressure.
  • It rotates in counter clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.
  • The process of cyclone formation and intensification is known as

Types of cyclones :

  • There are basically two types of cyclones.
  1. Tropical cyclones which occur in tropical areas around the world.

Tropical cyclones

  1. Temperate cyclones also known as extra tropical cyclones or wave cyclones occur due to fronts.

Temperate cyclones around the world

Tropical cyclones :

  • Tropical Cyclones are one of the most devastating natural calamities around the world.
  • These are violent storms which originate over the seas and oceans in tropical areas.
  • After originating they move over to the coastal areas bringing about large scale destruction.
  • The destruction is due to violent winds, very heavy rainfall.
  • They mostly originate and intensify over warm tropical oceans which acts as heat engine.
  • 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
    • Upper divergence above the sea level system.

Structure of the Tropical Cyclone :

  • The main parts of a tropical cyclone are the rainbands, the eye, and the
  • Air spirals in toward the center in a counter-clockwise pattern in the northern hemisphere (clockwise in the southern hemisphere), and out the top in the opposite direction.

Coastal areas vulnerable to cyclones in India :

Classification of Cyclones according to the wind speed :

Syllabus : Prelims + Mains; GS1 – Geography