1. THE EFFECTS OF OCEAN CIRCULATION ON CLIMATE AND WEATHER PATTERNS
(and Hurricanes)

3. How do currents affect the global climate, weather patterns
How do currents affect the global climate, weather patterns? They distribute heat.
The Gulf Stream brings heat to Western Europe.
Winds and water temperatures in the South Atlantic (off the coast of Africa) cause Hurricanes in North America
Changes in the direction of Ocean currents in the Pacific cause weather events like El Nino.

4. A Hurricane
is a severe tropical storm, that forms in the southern Atlantic Ocean, Caribbean Sea, Gulf of Mexico or in the eastern Pacific Ocean.
VIDEO

5. How do hurricanes form?
Hurricanes need warm tropical ocean’s 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.

7. Hurricanes: where do they occur?
between 5 and 30 latitude and initially move westward (owing to easterly winds) and slightly towards the poles.
Many hurricanes eventually drift far enough north or south to move into areas dominated by westerly winds (found in the middle latitudes). These winds tend to reverse the direction of the hurricane to an eastward path.

8. Atlantic Hurricane Season
June 1 and November 30

9. Accompanying phenomena
Hurricane waves - large waves up to 15 metres high are caused by the strong winds and bring about extensive flooding.
Swells - an increase in ocean level.
Rain - the hurricane picks up about 2 billion tons of moisture per day and releases it as rain.

10. What is storm surge?
Storm surges are frequently the most devastating element of a hurricane.
As a hurricane’s winds spiral around and around the storm, they push water into a mound at the storm’s center.
This mound of water becomes dangerous when the storm reaches land because it causes flooding along the coast.
The water piles up, unable to escape anywhere but on land as the storm carries it landward.
A hurricane will cause more storm surge in areas where the ocean floor slopes gradually. This causes major flooding.

11. Hurricane prediction
Other than basic knowledge of general hurricane occurrence there are no atmospheric conditions that can be measured and combined to predict where a hurricane will develop.
Therefore we can only forecast its path once formed.
Satellites detect hurricanes in their early stages of development and can help to provide early warning of imminent hurricanes..

12. Hurricane Facts:
Hurricanes rotate in a counterclockwise direction around an "eye."
Hurricanes have winds at least 100km per hour.
There are on average six Atlantic hurricanes each year.

13. Hurricanes
At 12:10 a.m. ADT, Monday September 29, 2003, Hurricane Juan made landfall in Nova Scotia as one of most powerful and damaging hurricanes to ever affect Canada.

15. Hurricane Grace et al The making of a perfect storm (1991)
Background read

16. THE PERFECT STORM
Question sheet to accompany