Tropical Revolving Storms

Question 1

What are tropical revolving storms

Answer 1

Intense low pressure weather systems that can develop in the tropics

Question 2

How big are tropical revolving storms

Answer 2

200-700 km in diameter

Question 3

What does a tropical revolving storm begin as

Answer 3

An area of low pressure, caused by surface heating into which air is drawn in a spiralling manner.

Question 4

What happens after the area of low pressure has occurred

Answer 4

They enlarge into tropical depressions with rotating wind systems and these may continue to grow into a much more intense and rapidly rotating system - the tropical revolving storm

Question 5

Why are tropically revolving storms triggered

Answer 5

Not entirely clear why- but several conditions need to be present

Question 6

What conditions are needed to start a revolving storm

Answer 6

• oceanic location and sea temperatures above 27
• ocean depth of 70m
• location at least 5 degrees north or south of the equator
• low level convergence of air in the lower atmospheric circulation system
• rapid outflow of air in the upper atmospheric circulation

Question 7

For a tropical revolving storm to occur, why is an oceanic location with sea temperatures above 27 degrees c needed?

Answer 7

It provides a continuous source of heat to maintain rising air currents

Question 8

For a tropical revolving storm to occur, why is an ocean depth of at least 70 m needed

Answer 8

Moisture provides latent heat, rising air causes the moisture to be released by condensation and the continuation of this process drives the system

Question 9

For a tropical revolving storm to occur, why is the location at least 5 degrees north or south of the equator

Answer 9

So that the coriolis force can bring about the maximum rotation of air (the coriolis force is weak at the equator an will stop a circular flow from developing)

Question 10

For a tropical revolving storm to occur, why is a low level convergence of air in the lower atmospheric system needed

Answer 10

Because winds have to come together near the centre of the low pressure zone

Question 11

For a tropical revolving storm to occur, why is a rapid outflow of air in the upper atmospheric circulation needed

Answer 11

It pushes away the warm air, which has risen close to the centre of the storm

Question 12

When does a tropical revolving storm exist

Answer 12

While there is a supply of latent heat and moisture to provide energy and low frictional drag on the surface. Once the system reaches maturity, a central eye develops.

Question 13

How big is the central eye of a storm

Answer 13

10-50 km in diameter in which there are calm conditions, clear skies, higher temperatures and descending air.

Question 14

Wind speeds of the central eye

Answer 14

300 km h-1

Question 15

What happens when the system reaches land or colder waters polewards

Answer 15

It will decline as the source of heat and moisture is removed