1. Monsoons and Hurricanes Driven by Surface Currents

2. Monsoons • Monsoon (Arabic for Season): A pattern of wind circulation that changes with the season. • Monsoons usually mean wet summers and dry winters. • Caused by uneven heating of land and water and the movement of the Intertropical Convergence Zone (ITCZ).

3. Monsoons • Spring/Summer: Land heats faster than ocean. Hot air rises over land and cool, moist air from the ocean moves inland causing clouds and rain. • Fall/Winter: Land cools faster than ocean. Air cools and sinks over land and dry surface winds moves seaward. Climate is now dry.

4. Monsoons • Intensity of monsoons depends on the location of the ITCZ. • Monsoons follow ITCZ south in Northern Hemisphere’s winter and north in its summer.

5. Monsoons • India can receive 10 meters (425 inches/30 feet!) of rain between April and October each year. • In Africa and Asia, over 2 Billion people depend on summer monsoon rains for drinking water and agricultural irrigation.

6. Hurricanes • Hurricanes need warm tropical oceans, moisture and light winds above them. • If the right conditions last long enough, a hurricane can produce violent winds, incredible waves, torrential rains and floods. • Also called Typhoons or Cyclones • Sustained winds of 74 MPH or greater • Avg. of 100 each year

7. Stages of Development • Strong Storm • Depression • Tropical Storm • Hurricane

8. Saffir-Simpson Hurricane Damage-Potential Scale