Context:
Cyclonic storm ‘Remal’ makes landfall in West Bengal and Bangladesh Coast
Tropical Cyclones:
- Rapidly rotating storms that are non-frontal low-pressure system originating over tropical oceans.
- Favourable Conditions for Tropical Cyclones –
- Sea surface with temperature higher than 27° C.Presence of Coriolis force.Small variations in vertical wind speed.A pre-existing weak low-pressure area.
- Upper divergence above the sea level system.
Structure of a tropical cyclone –
- Eye – A mature tropical cyclone is characterized by the strong spirally circulating wind around the centre which is called the eye.
- Region of lowest surface pressure and warmest temperatures
- There is little or no precipitation
- Eye wall – The eye is surrounded by the eyewall
- Area of highest surface winds in the tropical cyclone.
- Terminology of Tropical Cyclones – Cyclones (Indian Ocean), Hurricanes (Atlantic), Typhoons (Western Pacific and South China Sea) and Willy-willies (Western Australia).
Source: Economic Times
Previous Year Question
The 2004 Tsunami made people realise that mangroves can serve as a reliable safety hedge against coastal calamities. How do mangroves function as a safety hedge?
[UPSC Civil Service Exam – 2011 Prelims]
(a) The mangrove swamps separate the human settlements from the sea by a wide zone in which people neither live nor venture out.
(b) The mangroves provide both food and medicines which people are in need of after any natural disaster.
(c) The mangrove trees are tall with dense canopies and serve as an excellent shelter during a cyclone or Tsunami.
(d) The mangrove trees do not get uprooted by storms and tides because of their extensive roots
Answer: (d)
