Storm Hazards

Causes (& explanation)

• Sea temperatures above 27*C (thermal inertia > typically occurs at end of summer/beginning of autumn) > evaporation & energy for storm

• Ocean depth of at least 70m (for moisture & latent heat)

• Location beyond 5* north/south of equation (where Coriolis effect greatest), generally (5* - 30* at Hadley cell) > Coriolis effect greater further away from equator but too far = too cold

• Low-level convergence of air

• Rapid outflow of air in upper atmosphere (high-level divergence of air)

• Uniform wind direction all altitudes > storm can gain height and intensity

• Over oceans > air warm & full of moisture

Difference between hurricane/cyclone/typhoon

• Hurricane: North Atlantic Ocean

• Cyclone: South Pacific Ocean/Indian Ocean

• Typhoon: North-west Pacific Ocean

Tropical storm

A powerful low pressure wind system with sustained winds of >75 mph (or 120 kph).

AO2 point

Energy released in hurricane = 500,000 small atomic bombs

Coriolis effect (& what it causes)

Rotation > difference in speed (between poles & equator) > vertical-moving winds are deflected (clockwise towards poles, vice-versa, halves of hemisphere act in opposite directions)

• Cause: 6 wind belt/atmospheric cells

Why equator hotter than Poles

• Equator: direct, concentrated sunlight

• Poles: dispersed sunlight at an angle

How winds created

Air tries to spread heat between hot & cold areas