Hurricanes

Question 1

Hurricane first step.

Answer 1

Falling air pressure pulls in denser, colder air from its surroundings, creating an anti-clockwise (NH) upward spiral of increasing wind speeds

Question 2

Hurricane second step.

Answer 2

Water vapour evaporated from the ocean rises and cools rapidly creating a massive wall of cumulonimbus cloud around the central eye

Question 3

Hurricane third step.

Answer 3

Condensation releases latent heat, which increases energy and wind speeds, pushing the riding air to an altitude of 10km above the ocean.

Question 4

Hurricane fourth step.

Answer 4

At the top of the hurricane the cooling air spreads outwards creating a thick canopy of cirrus clouds up to 1,500 km across.

Question 5

Definition of a hurricane.

Answer 5

A tropical storm with sustained wind speeds in excess of 120km h-1.

Question 6

Hurricane prerequisites.

Answer 6

• Water over 100m deep
• Water above 26 degrees C
• Little or no upper air sheer
• 5-20 latitude north or south of the equator (ITCZ)
• Over 75% humidity