1. Chapter 26 Modern Earth Science
Climate
Chapter 26
Modern Earth Science

2. 26.1 Factors That Affect Climate
climate the average weather conditions in an area over a long period of time
Temperature Range: the difference between the highest and lowest temperatures of a month
Precipitation: The average amount of rainfall an area can acquire over a year
The climate of a region can also be affected by the
Latitude of a region
Heat absorption and release
Topography
Winds
Ocean currents

4. Latitude Latitude is the distance from the equator.
Latitude determines the amount of solar energy received, and the prevailing winds of a region
The higher the latitude of an area is, the smaller the angle at which the sun’s rays hit Earth is and the smaller the amount of solar energy received by the area is.

5. Solar Energy
Because Earth’s axis is tilted, the angle at which the sun’s rays hit an area changes as Earth orbits the sun.
Equatorial regions: 12 hours day & night with steady high temperatures.
Polar regions: large variation of daylight hours, steady low temperatures.

7. Wind Patterns Latitude determines global winds
Winds affect humidity, precipitation, temperature, & cloud cover.
Different prevailing winds = different climate
Global winds also affected by ocean currents & major mountain ranges.

8. Heat Absorption & Release
specific heat the quantity of heat required to raise the temperature of 1 gram of a substance 1°C
Even if not in motion, water warms more slowly than land does.
Water also releases heat energy more slowly than land does.

9. Heat Absorption & Release 2
Land heats faster than water and thus can reach higher temperatures in the same amount of time.
Waves, currents, and other movements continuously replace warm surface water with cooler water from the ocean depths.
In turn, the temperature of the land or ocean influences the amount of heat that the air above the land or ocean absorbs or releases.
The temperature of the air then affects the climate of the area.

10. Ocean Currents Water moves around the globe – LAND DOESN’T
The temperature of ocean currents that come in contact with the air influences the amount of heat absorbed or released by the air.
The temperature of the air moving ONTO SHORE is affected by the temperature of the ocean/water it comes into contact with

12. Seasonal Winds
monsoon a seasonal wind that blows toward the land in the summer, bringing heavy rains, and that blows away from the land in the winter, bringing dry weather
Temperature differences between the land and the oceans sometimes cause winds to shift seasonally in some regions.
Monsoon climates, such as that in southern Asia, are caused by heating and cooling of the northern Indian peninsula.

13. Topography
Elevation
The surface features of the land, or topography, also influences climate.
The elevation, or height of landforms above sea level, produces distinct temperature changes.
Temperature generally decreases as elevation increases.

14. More Topography Rain Shadows
When a moving air mass encounters a mountain range, the air mass rises, cools, and loses most of its moisture through precipitation.
As a result, the air that flows down the other side of the range is usually warm and dry. This effect is called a rain shadow.
One type of warm, dry wind that forms in this way is a foehn (FAYN), a dry wind that flows down the slopes of the Alps.

16. 26.2 Climate Zones

17. Climate Zones 3 Major Climate Zones Polar Climate
Middle-latitude Climate
Tropical Climate

18. Tropical Climate
3 Tropical Climates
Desert
Rain Forest
Savanna

19. Polar Climate 2 Polar Climates Subarctic Tundra
Severe winters & short summers
Canada
Tundra
No trees, very dry, cold air with little precipitation
Northern Alaska

20. Middle-Latitude Climate
5 Climates
Desert & Steppe
Eastern Montana
Mediterranean
Most of California
Marine West-Coast
Seattle
Humid Sub-tropical
Georgia
Humid Continental
Iowa

21. US: The Middle Latitude Climate
Marine West Coast Climate
Mediterranean
Middle Latitude Steppe
Middle Latitude Desert
Humid Continental
Humid Subtropical

22. Tropical Rain Forest Warm & humid
Near the equator (5 - 10° north & south)
Dense, rain-forest vegetation
Annual rainfall more than 250 cm
Yearly temp. range only about 3° C
Amazon River basin, parts of Central America & Southeast Asia

23. Tropical Desert

24. Tropical Savanna

25. Polar Climates

27. Subarctic

28. Tundra

29. Middle-Latitude Climates