Characteristics of a Tropical Cyclone
Geography: Edexcel IGCSE, topic 1.3.1
Characteristics of Tropical Cyclones
Tropical storms form over water that is 26.5oC or warmer and when there's a small difference in wind speeds between the upper atmosphere and the lower atmosphere.
Form over warm water
- Tropical storms form over water that is 26.5oC or warmer.
- These temperatures are favourable because they mean there's lots of warm, moist air to cause extreme rain. Energy from warm water intensifies cyclones.
- Lots and lots of energy is released when air evaporates, rises or cools. This increases the speed and energy of a storm.
- The strength of a storm falls as they move further away from warm water (so when storms are above land or above cooler parts of the ocean).
Move west
- Near the equator, surface winds are mainly trade winds moving east.
- The trade winds and something called the Coriolis Effect mean that tropical storms move from east to west.
Spin
- The rotation of the Earth causes the Coriolis effect, which makes tropical storms spin by deflecting winds.
Source areas
- The source area for most cyclones is between 5o and 30o north and south because the water is below 26.5oC further from the equator.
- Most cyclones form when sea temperatures are warmest, which is June-November in the northern hemisphere, and November-April in the southern hemisphere.
Test yourself on Characteristics of a Tropical Cyclone
What temperature must water be for a tropical cyclone to develop over it?
Near the equator, which direction do tropical cyclones tend to move?
Which of the following describes tropical cyclones?
Which of the following best describes the source areas for most tropical cyclones?