Climate & Vegetation

1. Climate & Vegetation Chapter 3

2. Earth-Sun Relationships • Axis – imaginary line that run through the center of the Earth • Earth’s axis is tilted 23 ½ ° • Earth’s tilt affects the climate since all places do not receive the same amount of direct sunlight.

3. Earth-Sun Relationships • Revolution – orbit around the sun • Earth’s revolution takes 365 ¼ days. • Revolution causes the changing seasons.

4. Earth-Sun Relationships • Rotation – spinning on its axis • The Earth’s rotation takes 24 hours. • Rotation causes day and night.

5. Earth-Sun Relationships • Equinox – either of the 2 times each year (spring and fall) when day and night are of nearly equal length everywhere on Earth • Solstice – either of the 2 times a year (summer and winter) when the sun appears directly overhead at noon to observers at the Tropics of Cancer and Capricorn

6. Weather vs. Climate • Weather - condition of the atmosphere at a particular location and time. • Climate – the term for weather conditions at a particular location over a long period of time

7. Weather Extremes • Hurricanes • Tornadoes • Blizzards • Droughts • Floods

8. Factors that Affect Climate Latitude – the amount of direct sunlight affects climate • Places closer to the Equator receive more direct sunlight than areas closer to the poles which receive slanted rays.

9. Factors that Affect Climate Landforms – mountains can block precipitation which can affect climate. This is called the orographic effect (rain shadow). • Ex. - Sierra Nevada range and the Mojave Desert • Windward side – wet • Leeward side - dry

10. Factors that Affect Climate Wind currents • Prevailing winds are winds that blow in a fairly constant pattern. • The direction of the winds can determine what type of weather patterns an area will see.

12. Factors that Affect Climate Ocean currents – cold and warm “rivers” of water known as currents, flow in the ocean • Cold currents cool the lands they pass while warm currents have a warming effect. • Ex. North Atlantic Drift flows near western Europe and gives the area a mild climate despite its northerly latitude

13. North Atlantic Drift

14. Factors that Affect Climate Proximity to large bodies of water • Water is slower to heat and cool than land. • Water temperatures are more constant and uniform than land temperatures. • Temperatures of land areas located near oceans do not change as much as interior land areas.

15. Factors that Affect Climate Proximity to large bodies of water Example: CityNewport, OR Rapid City, SD Location 44°N, 124°W 44°N, 103°W Average Jan. 44° F Jan. 22° F Temperatures July 57° F July 72° F

16. Factors that Affect Climate Elevation – for every 1,000 feet gained, the temperature drops about 3.5° F. • Mt. Kilimanjaro in Africa is located near the Equator, but is covered with snow and ice

17. Changes in Climate • El Nino – warming of the waters off the west coast of South America • About every 7 years, prevailing easterly winds that blow over the central Pacific Ocean slow or reverse direction • The winds push warm ocean water toward the Americas causing floods and mudslides, Australia and Asia experience drought conditions • The reverse is called La Nina – this causes an increase in precipitation in places such as India and dryness along the Pacific coast of the Americas

19. Changes in Climate • Global Warming – although controversy exists over the causes of global warming, scientists agree temperatures are increasing • Some believe the cause is the greenhouse effect – layer of gases released by burning of coal and petroleum traps some solar energy, causing higher temperatures • Scientist predict that, if global warming continues, ice caps will melt, flooding some coastal areas, covering islands, and changing the global climate

21. 5 Major Climate Regions • Tropical • Dry • Mid-Latitude • High-Latitude • Highlands • See pages 60-61

22. Types of Precipitation • Convectional –hot, humid air rises and cools losing its ability to hold water (ex. Tropical rainforest) • Orographic – warm moist air is forced up when passing over high landforms • Frontal – 2 fronts of different temperatures meet

23. Convectional Precipitation

24. Frontal Precipitation

25. Orographic Precipitation

26. Four Types of Vegetation • Forest • Grassland • Desert • Tundra

27. Forest • Tropical rainforest • Deciduous forest – broadleaf, such as maple and oak • Coniferous forest – cone bearing, evergreens • Chaparral

28. Forest

29. Grassland • Tropical grasslands (savannas) • Temperate grasslands (prairies, steppes, pampas)

30. Grasslands

31. Desert • A desert can occur where there is a lack of precipitation, less than 10 inches a year. • Deserts can be cold, they do not have to be hot and sandy. • Vegetation – plants that can conserve water & withstand heat such as cacti & sagebrush

32. Desert

33. Tundra • Alpine tundra • Arctic tundra • Vegetation – includes mosses & lichens Anaktuvuk Pass, Alaska