Hurricane Ida

 

Hurricane Ida- Relevance for UPSC Exam

• GS Paper 1: Salient features of world’s physical geography- Important Geophysical phenomena such as earthquakes, Tsunami, Volcanic activity, cyclones, etc.

 

Hurricane Ida- Context

• Recently, Hurricane Ida made landfall in Louisiana, the USA as an extremely dangerous Category 4 storm.
• Hurricane Ida has been put into Category 4 hurricane on the five-step Saffir-Simpson scale with top sustained winds of 240 km per hour.

 

Hurricanes- Categorization

• Saffir-Simpson scale: based on wind speed, Hurricanes are categorized on the Saffir-Simpson on a scale of 1 to 5.
  • Hurricanes that reach category three or higher are classified as major hurricanes because of their potential to cause devastating damage to life and property.

 

Hurricanes- Key Points

• About: Hurricane is basically a tropical cyclone that occurs in the Atlantic Ocean and the northeastern Pacific Ocean.
  • Tropical cyclone: It is an intense circular storm that originates over warm tropical oceans and is characterized by low atmospheric pressure, high winds, and heavy rain.
• Location of Formation: Tropical Cyclone or Hurricanes are formed over warm ocean waters near the equator.
• Duration of formation:
  • Atlantic Hurricanes: often formed from June to November and covers the Atlantic Ocean, the Caribbean Sea, and the Gulf of Mexico.
  • Eastern Pacific Hurricanes: Formed from May 15 to November 30.

 

Tropical cyclones or hurricanes- Pre-Conditions

• Presence of large sea surface with warm ocean water: temperature of the top layer of the sea should be at least 28°C, up to a depth of about 60 meters.
• Presence of Coriolis force enough to create a cyclonic vortex: This helps in an ‘anticlockwise’ rotation in the northern hemisphere and clockwise in the southern hemisphere, resulting in the formation of Tropical Cyclones/Hurricanes.
• 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.

 

Other Names of Tropical Cyclones

• Tropical Cyclones are called by different names depending upon the location of their occurrence. They are as follows-

Name of Tropical Cyclone	Location in the World
Typhoons	China Sea and the Pacific Ocean
Hurricanes	The Caribbean Sea and the Atlantic Ocean
Willy-willies	North-western Australia
Tropical Cyclones	Indian Ocean Region