Worldwide Wind and Ocean Currents

1
Worldwide Wind and Ocean Currents

• Science 10

2
Global Warming and Cooling of Air

• Air is warmest at the equator and coolest at
  poles
• So air should rise at the equator and sink at the
  poles
• However, due to the size of the Earth, air from
  the equator cools before it reaches the poles and
  air from the poles will warm before it reaches
  the equator

3
Actual Wind Currents

• Air from the equator will cool by about 30
  latitude and sink
• Air from the pole will warm by about 60 latitude
  and rise
• Further, air descends at 30 and rises at 60

4
Coriolis Effect

• Due to the rotation of the Earth, any object that
  moves across the surface of the Earth will be
  pushed to the left or right
• The deflection direction is shown in the diagram

5
Global Wind Patterns

• Main wind currents
• Polar Easterlies (north and south)
• Prevailing Westerlies (north and south)
• Northeast Tradewinds (north only)
• Southeast Tradewinds (south only)

6
Jet Stream

• Polar Easterlies collide with Prevailing
  Westerlies
• Warmer Prevailing Westerlies climb over the
  cooler Polar Easterlies and result in a fast
  moving stream of air at the edge of the
  troposphere

7
Ocean Currents

• Due to the uneven heating of the oceans,
  convection currents are established
• Cold currents carry cold air and warm currents
  carry warm air so continental weather is affected
  by the currents

8
Great Ocean Conveyor Belt

• The largest continuous ocean current that covers
  most of the globe
• Warm water is near the surface while cooler water
  travels at depth

9
Upwelling

• When wind blows surface water away from land, the
  cool water from below will rush up to replace it
• This leads to colder surface water than would be
  expected

10
Problems

• Page 468
• Questions 1-6
• Page 478
• Questions 1-4