Cyclone Titli upgraded to ‘very severe storm: 3 Andhra districts on high alert

  • What is Cyclone? Where does it derive its energy?

  • How are cyclones categorized ?

  • How are Cyclones named?

  • When did we start naming Cyclones?

  • What happens to the names of the storms that are very severe?

GS paper 1 (Important Geophysical phenomena such as earthquakes, Tsunami, Volcanic activity, cyclone)

In this video, you can find detailed answers for all the above questions.

What is the context about?

  • The weather bureau said cyclone Titli intensified into a very severe cyclonic storm as heavy rains lashed Odisha’s Ganjam, Gajapati, Puri, Balasore and Kendrapara districts.
  • The MeT department upgraded cyclone Titli to ‘very severe cyclonic storm’ on October 10 and it is expected to make a landfall on October 11 in Odisha and adjoining north Andhra Pradesh coasts between Gopalpur and Kalingapatnam.

What is Cyclone? Where does it derive its energy?

  • A cyclone is an area of closed, circular fluid motion rotating in the same direction as the Earth.
  • This is usually characterized by inward spiraling winds that rotate anti-clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere of the Earth.
  • Most large-scale cyclonic circulations are centered on areas of low atmospheric pressure.
  • The main source of energy for tropical cyclones is the warm oceans in the tropical regions.
  • To initiate a tropical cyclone the sea-surface temperature generally needs to be above 26.5°C. However, existing cyclones often persist as they move over cooler waters.

How are cyclones categorized ?

  • Category 1: Wind and gales of 90-125 kph, negligible house damage, some damage to trees and crops.
  • Category 2: Destructive winds of 125-164 kph. Minor house damage, significant damage to trees, crops and vehicles, risk of power failure.
  • Category 3: Very destructive winds of 165-224 kph. Some roof and structural damage, some caravans destroyed, power failure likely.
  • Category 4: Very destructive winds of 225-279 kph. Significant roofing loss and structural damage, vehicles blown away, widespread power failures.
  • Category 5: Very destructive winds gusts of more than 280 kph. Extremely dangerous with widespread destruction.

How are Cyclones named?

  • Cyclones were usually not named. The tradition started with hurricanes in the Atlantic Ocean, where tropical storms that reach sustained wind speeds of 39 miles per hour were given names. (Incidentally, hurricanes, typhoons, cyclones are all the same, just different names for tropical storms in different parts of the world; Hurricane in the Atlantic, Typhoon in the Pacific and Cyclone in the Indian Ocean).
  • If the storm’s wind speed reaches or crosses 74 mph, it is then classified into a hurricane/cyclone/typhoon. Tropical storms are given names and they retain the name if they develop into a cyclone/hurricane/typhoon.

When did we start naming Cyclones?

  • Tropical cyclones are named to provide easy communication between forecasters and the general public regarding forecasts, watches, and warnings.
  • The first use of a proper name for a tropical cyclone was by an Australian forecaster early in the 20th century. He gave tropical cyclone names after political figures he disliked.
  • During World War II, tropical cyclones were informally given women’s names by US Army Air Corp and Navy meteorologists (after their girlfriends or wives) who were monitoring and forecasting tropical cyclones over the Pacific. And the practice of naming continued.

What happens to the names of the storms that are very severe?

  • Names of some storms that cause widespread damage and deaths are usually retired and are not brought back or reused later, at least for 10 years. These names are then replaced with new names.
  • The names are retired as a mark of respect to the dead. Once a name is officially retired, it is then replaced with a name of the same gender and beginning with the same letter.
  • So far, since 1972, there have been 50 names that have been retired.

The above article has been retrieved from:               HT Correspondent. ( 2018, October , 11). Cyclone Titli upgraded to ‘very severe storm’: What cyclone categories mean. Hindustan Times. Retrieved from https://www.hindustantimes.com/india-news/cyclone-titli-upgraded-to-very-severe-storm-what-cyclone-categories-mean/story-UqJVclvMfjalDgyX3jUuiN.html