UPSC CAPF AC 2018 Paper

Tropical cyclones are violent storms that originate over oceans in tropical areas and move over to the coastal areas bringing about large scale destruction caused by violent winds, very heavy rainfall and storm surges.Tropical cyclones originateand intensify over warm tropical oceans. The conditions favourable for the formation and intensification of tropical storms are: (i) Large sea surface with temperature higher than 27° C; (ii) Presence of the Coriolis force; (iii) Small variations in the vertical wind speed; (iv) A pre-existing weak/low-pressure area or low-level-cyclonic circulation; (v) Upper divergence above the sea level system. A mature tropical cyclone is characterised by the strong spirally circulating windaround the centre, called the eye. The diameter of the circulating system can vary between 150 and 250 km.