What is the minimum sea surface temperature generally required for a tropical cyclone to form?
- A.About 16.5 degrees Celsius
- B.About 20 degrees Celsius
- C.About 26.5 degrees Celsius
- D.About 36.5 degrees Celsius
Correct answer
Explanation
The correct answer is C, about 26.5 degrees Celsius. A tropical cyclone runs on the latent heat released when water vapour condenses, so it needs a sea whose surface is at about 26.5 degrees Celsius or warmer, with that warm water reaching down about fifty metres, so that the churning of the sea does not cool the surface. This is why the storms belong to the tropical oceans and to the warmest months. Option A, 16.5 degrees Celsius, and option B, 20 degrees Celsius, are too cold to supply enough vapour; a system over such water weakens instead of deepening, which is what happens when a cyclone drifts into higher latitudes. Option D, 36.5 degrees Celsius, is not reached by open ocean water anywhere on earth, since the warmest tropical seas stay near thirty degrees Celsius. Remember 26.5 degrees Celsius along with the other conditions, the Coriolis force and weak vertical wind shear.
Read the full article: Cyclones: Naming, IMD Categories and Warning Stages
Practice Questions
View allA cyclone is known by different names in different parts of the world. In Philippines it is called as _______.
- A.willy-willy
- B.hurricane
- C.typhoon
- D.mango shower
Show answer
The Philippines lies in the western North Pacific, and every tropical cyclone of that basin, whether it strikes the Philippines, China or Japan, is called a typhoon.
Read the full explanation →According to the India Meteorological Department, a system is classified as a super cyclonic storm when the sustained wind speed is at least
- A.118 km/h
- B.167 km/h
- C.222 km/h
- D.300 km/h
Show answer
The India Meteorological Department puts a system in the highest class, super cyclonic storm, when the sustained wind at its centre reaches 222 km/h, which is 120 knots.
Read the full explanation →In which year did the naming of tropical cyclones in the north Indian Ocean begin?
- A.1999
- B.2004
- C.2013
- D.2018
Show answer
The eight countries of the WMO and ESCAP Panel on Tropical Cyclones agreed on a list of names for this basin and began using them in 2004, long after the Atlantic, where naming had been practice for decades.
Read the full explanation →Which body names the tropical cyclones of the north Indian Ocean?
- A.The Regional Specialised Meteorological Centre, New Delhi
- B.The National Disaster Management Authority
- C.The Indian National Centre for Ocean Information Services
- D.The National Centre for Medium Range Weather Forecasting
Show answer
The names themselves are contributed by the thirteen member countries of the panel, but the centre at New Delhi, which the India Meteorological Department runs, takes the next name from the list, announces it when a deep depression strengthens into a cyclonic storm, and issues advisories to all the member…
Read the full explanation →How many hours in advance is a pre-cyclone watch, the first stage of the India Meteorological Department warning, issued?
- A.12 hours
- B.24 hours
- C.48 hours
- D.72 hours
Show answer
The warning comes in four stages, each tied to a number of hours before the adverse weather is expected on the coast.
Read the full explanation →