Conditions Necessary for The Formation of A Tropical Cyclone Flashcards
What is a tropical cyclone?
A rapidly rotating violent storm that originates over tropical oceans in late summers.
What is the minimum sea surface temperature required for cyclone formation?
Higher than 27°C.
Why is a large sea surface area important for tropical cyclones?
It provides enough heat and moisture to sustain convection.
What is the role of the Coriolis force in tropical cyclone formation?
It helps create the cyclonic vortex necessary for the storm’s rotation.
Why do cyclones not form at the equator?
The Coriolis force is zero at the equator, preventing rotation.
What is a pre-existing low-pressure area, and why is it important?
A region of weak low pressure that provides a starting point for storm intensification.
What is wind shear, and how does it affect tropical cyclones?
Wind shear is the difference in wind speed at different altitudes; low wind shear is needed for cyclone development.
What is upper-level divergence, and why is it necessary?
It helps remove rising air, allowing more warm air to enter the system and fuel the cyclone.
Why does a warm ocean surface provide a good source of latent heat?
It supplies moisture, which releases latent heat of condensation, driving convection.
How deep must warm ocean water be for a cyclone to form?
60–70 meters deep to sustain the storm.
Why do tropical cyclones mostly form on the western margins of oceans?
Warm ocean currents create a thick layer of warm water.
Why are cyclones rare on the eastern margins of oceans?
Cold ocean currents lower the surface temperature, making conditions unfavorable.
What happens to a cyclone when it makes landfall?
It weakens because it is cut off from its moisture source.
What is the adiabatic lapse rate, and how does it affect cyclone formation?
The rate at which rising air cools, causing condensation and release of latent heat.
Why do cyclones form mostly in late summers?
Ocean temperatures peak in August to mid-November, providing ideal conditions.
What is a low-level disturbance in the ITCZ?
A weak low-pressure system that can develop into a cyclone.
What is an easterly wave disturbance?
A convective system moving westward, often leading to cyclone formation.
Why do fewer cyclones form over the Arabian Sea than the Bay of Bengal?
The Bay of Bengal is warmer and receives more low-level disturbances.
How does monsoon winds impact cyclone formation in the Arabian Sea?
They drive moisture away, reducing cyclone frequency.
What is the vapour pressure of water, and why is it important?
The pressure exerted by water vapor; higher vapour pressure increases evaporation.
How does salinity affect cyclone formation?
High salinity reduces evaporation, making cyclone formation less likely.
Why does temperature contrast between air masses aid cyclone formation?
It causes instability and encourages low-level disturbances.
What is the role of vertical wind shear in cyclone formation?
Low wind shear helps maintain tall cumulonimbus clouds needed for cyclones.
Why do cyclones not form in temperate regions?
High vertical wind shear disrupts cyclonic convection.
