Worldwide Wind and Ocean Currents Science 10

Global Warming and Cooling of Air Air is warmest at the equator and coolest at poles Air is warmest at the equator and coolest at poles So air should rise at the equator and sink at the 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 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

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

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 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 The deflection direction is shown in the diagram

Global Wind Patterns Main wind currents: Main wind currents: –Polar Easterlies (north and south) –Prevailing Westerlies (north and south) –Northeast Tradewinds (north only) –Southeast Tradewinds (south only)

Jet Stream Polar Easterlies collide with Prevailing Westerlies 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

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

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

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