1. What causes climate ?

2. Climate The average year-after-year conditions in a region.
Determined by the precipitation and temperature of the region.

3. Precipitation
The amount of rain or snow that falls in a given region in a year.

4. Two factors that determine the amount of precipitation a region receives:
Prevailing winds
Mountain ranges

5. Prevailing Winds Move the large air masses that create
weather patterns.
Amount of water vapor in the air masses influences the amount of precipitation.

6. Water Vapor in the Air Warm air holds lots of water vapor – humid air.
Cold air is dry air.

7. Wind Direction
Amount of water vapor depends on where the wind comes from.
Winds blowing inland from oceans carry lots of water vapor.
Winds blowing from land areas carry very little water vapor.

8. Mountain Ranges
A mountain range in the path of prevailing winds influences where the precipitation falls.

9. Windward Side
The side of the mountain that is hit by the oncoming prevailing winds.
The side that
receives the
moisture out of the air.

10. Leeward Side The land on the other side of the mountain.
This is the cool,
dry side of
the mountain.
Water in the air has already fallen out.

11. Temperature Helps determine the climate in a region.
Temperature is influenced by several factors.

12. Latitude Distance of the area above or below the Equator.
Determines how the sun’s rays strike the surface of the Earth.

13. Temperature Zones
Determined by the distance of the area above and below the Equator.
There are 3
separate zones.

14. Tropical Zone Receives the most direct sunlight at the Equator.
Climate is hot
year around.

15. Temperate Zone
Receives both direct and indirect sunlight due to the tilt of the Earth on its axis.
Has both cold
and warm climates
through out the
year.

16. Polar Zone
The sun’s rays striking the Earth with the most indirect rays.
Area has a
cold climate.

17. Altitude
Distance the area is above
sea level.

18. In mountainous regions, altitude is more important than latitude.
Temperature of the air decreases as the altitude increases.

19. Distance from Water Oceans moderate the temperature of an area.
Water heats up and cools
down more slowly
than the land.

20. Marine Climates Have warm winters and cool summers. Found on the west
coasts of North
and South America.

21. Continental Climates Areas of land far inland.
Have extreme temperatures.
Winters are cold
and summers
are hot.

22. Ocean Currents
Currents are streams of water within the oceans that move in regular patterns.

23. Warm Currents Carry warm water from the tropics toward the poles.
Brings warm air to the land.
Gulf Stream – a warm current that gives England a warm, wet climate.

24. Cold Currents Bring cold water from the poles to the Equator.
Brings cool air to the
land they move by.
California Current – a cold current that flows south from Alaska and makes the West Coast climate cooler than expected.