B.1.3 Hurricanes and Their Impacts on Coastal Margins Notes

Understanding Storm Systems and Coastal Impacts

1. Imagine standing on a beach, watching the ocean churn as dark clouds gather overhead.
2. The air feels heavy, and the wind picks up speed.
3. This is the beginning of a storm system, a powerful force of nature that can reshape coastlines and disrupt lives.

How Storm Systems Form

1. Warm Ocean Water: The ocean surface must be at least 26°C to provide the heat energy needed for evaporation and ocean water has to be similarly warm to a depth of 50-70 meters.
2. Rising Air and Low Pressure: As warm, moist air rises, it cools and condenses into clouds, releasing latent heat. This heat causes more air to rise, creating a low-pressure area at the surface.
3. Coriolis Effect: The Earth’s rotation causes the rising air to spin, forming the characteristic spiraling winds of a storm system.
4. Air and Water Circulation: The cooled off air descends along the edges of the system and rushes towards the center to equalize the air pressure - this causes extreme winds. At the same time the water held in clouds starts to fall - this causes extreme precipitation.
5. Sustained Energy: The storm continues to grow as long as it remains over warm water and away from land, where friction and cooler temperatures weaken it.

Where Do Storm Systems Occur?

1. Tropical Regions: Storm systems form between 5° and 30° latitude in both hemispheres, where ocean temperatures are warm enough.
2. Major Ocean Basins where tropical storms carry three different regional names:

• Atlantic Ocean: Hurricanes often impact the Caribbean, Gulf of Mexico, and the eastern United States.
• Pacific Ocean: Typhoons affect Southeast Asia, Japan, and the western Pacific islands.
• Indian Ocean: Cyclones impact countries like India, Bangladesh, and Madagascar.

Physical Impacts of Storm Systems