Tropical Cyclones 2.5a Flashcards
How does a tropical cyclone form and what are the conditions needed for it to form?
They need warm, moist air and warm ocean temps. Firstly, the warm air rising causes thunderstorms which group together and make a strong flow. Very low pressure forms at the center of the storms, then, the storms start to rotate and accelerate in and up.
Where and Why do they form ?
They form in tropical areas and they form because of the Coriolis effect, a rotation force that forms part of the global circulation of the atmosphere. The rotation force is due to deflection of winds moving North and South of the Equator.
What are tropical cyclone characteristics?
They have very low pressure, form a cylinder of rising, spiraling air surrounding an eye of descending high - pressure air, they have cloud banks which surround the eye - ‘eye wall’, and they are often 400km wide and 10km high.
When are tropical cyclones most likely to occur?
June-November in the Northern tropics, November-April in the Southern tropics.
How is the movement and track determined for a tropical cyclone?
Movement is determined by the prevailing wind and ocean currents. The track is influenced by how far it travels over the ocean, more time over the ocean means collecting more moisture which increases strength.
