Hazardous Earth - Tropical cyclone intensity

Question 1

What scale is used to measure the intensity of tropical cyclones and how many categories are there

Answer 1

The Saffir-Simpson scale; there are 5 categories - 4 and 5 cause wide spread destruction

Question 2

Name 6 factors that cause tropical cyclones to form

Answer 2

(1) warm sea water - Once the ocean water reaches at least 27°C, the warm air rises quickly, causing an area of very low pressure
(2) The rapid cooling, rising air must condense quickly to generate the high amounts of energy powering a tropical cyclone and creating cumulonimbus clouds.
(2) High humidity - there needs to be lots of moisture in the atmosphere
(4) Atmosphere (low wind shear) - if winds are blowing up in different direction up through the atmosphere, the cyclone won’t form
(5) Coriolis force is needed to given the cyclone spin - not usually strong enough within 5 degrees of the equator
(6) Pre-existing low-pressure disturbances - usually form when smaller storms come together.

Question 3

What makes tropical cyclones worse

Answer 3

(1) warmer water
(2) there is a low wind shear
(3) there is high humidity

Question 4

What makes tropical cyclones get weaker (dissipate)

Answer 4

(1) They reach land - as they lose energy (remember cyclones are powered by warm water
(2) They move into areas of colder water
(3) run into other weather systems where winds are blowing in different directions

Question 5

Explain two reasons why topical cyclones do not form in the UK

Answer 5

(1) they need water temps of over 26.5degress to form, which is a lot warmer than UK sea
(2) need wind speeds and direction to be similar up through the atmosphere - UK climate is dominated y weather fronts where wind speeds and directions change through the atmosphere