- 04 Dec 2020
- 2 min read
Why in News
Recently cyclone Burevi has made a landfall on Sri Lanka’s Northern and Eastern provinces, before heading towards south India.
- This comes days after Cyclone Nivar hit the Puducherry coast.
- Named by:
- Burevi vs Nivar:
- Cyclone Burevi would not strengthen beyond the intensity of a cyclonic storm because of upwelling caused by Nivar.
- Upwelling is the process in which cooler waters from lower ocean surfaces are pushed towards upper ocean surfaces.
- In the absence of warm sea surface conditions, any cyclone, in this case Burevi, will not get enough fuel to intensify further while at sea.
- Further, interaction with land mass has slowed its movement and intensity.
- A tropical cyclone is an intense circular storm that originates over warm tropical oceans and is characterized by low atmospheric pressure, high winds, and heavy rain.
- A characteristic feature of tropical cyclones is the eye, a central region of clear skies, warm temperatures, and low atmospheric pressure.
- Storms of this type are called hurricanes in the North Atlantic and eastern Pacific and typhoons in SouthEast Asia and China. They are called tropical cyclones in the southwest Pacific and Indian Ocean region and Willy-willies in north-western Australia.
- Storms rotate counterclockwise in the northern hemisphere and clockwise in the southern hemisphere.
- 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 or low-level-cyclonic circulation.
- Upper divergence above the sea level system.