Tropical storms

How are tropical storms measured

• Saffir Simpson scale

What conditions are needed for a tropical storm to form

• At least 27°C sea temp provides heat source and moisture

• Warm deep ocean water at least 70m ensures continuous evaporation and energy source

• Coriolis effect must be 5°–20° latitude

• Low wind sheer

• High humidity

How do tropical storms form

1. Warm ocean air heats air above it so it rises and creates a low-pressure area

2. Surrounding air replaces rising air and spirals due to Coriolis effect

3. Rising air condenses forming eyewall of storm and produce heavy rainfall

4. Condensation releases latent heat which powers rising air strengthening storm

What is the structure of a tropical storm

• The eye: Calm clear centre, descending air

• Eyewall: Strongest winds and heaviest rain, most intense convection

• Rainbands: Bands of thunderstorms spiralling outwards

What hazards do tropical storms cause

• Storm surge: Strong winds push seawater towards coast, low pressure causes sea levels to rise, causing coastal flooding

• Heavy rainfall: From intense convection and condensation, leads to river flooding and landslides

• Strong winds: Up to 74mph wreaking havoc

What is the distribution of the formation of tropical storms

• Atlantic Ocean, Pacific Ocean, Indian Ocean

• Between the tropics at 5°–30° from equator

• Form in the East travel Westward and deflect North and South

• Mostly form near the end of Summer

What is the ITCZ

Intertropical convergence zone where trade winds from Northern and Southern hemisphere meet and warm air is forced to rise, leading to cloud formation and heavy rainfall essential for tropical storm formation

How can climate change influence tropical storms

• Increase frequency and intensity rising global temperatures warm ocean surfaces, providing more energy for storm development and warmer oceans increase evaporation, leading to more moisture in the atmosphere and therefore stronger winds and heavier rainfall