Earth's Climate Zones: Understanding Weather and Climate Patterns

1. Chapter 7 CLIMATE & BIODIVERSITY

2. Natural Capital: Generalized Map of the Earth’s Current Climate Zones

3. What’s the difference between weather & climate? • Weather • Temperature, precipitation, wind speed, cloud cover • Hours to days • Climate • Area’s general pattern of atmospheric conditions over decades and longer • Humans have been keeping records of these patterns long enough to make predictions about and have expectations of specific patterns all over the earth

4. So, what causes variation in climate? • Climate varies in different parts of earth mostly because, over long periods of time, patterns of global air circulation and ocean currents distribute heat and precipitation unevenly between the tropics and other parts of the world • Three major factors determine how air circulates in the lower atmosphere: 1. Uneven heating of the earth’s surface by the sun 2. The rotation of earth on its axis 3. Physical properties of air, water and land

5. Prevailing winds blowing over the surface of the oceans produce mass movements of surface water called ocean currents • Earth’s major ocean currents redistribute the heat from the sun which greatly affects the climates of coastal areas • Large, intra-continental lakes also have this same effect on the land mass that surrounds them

6. Global Air Circulation Fig. 7-3, p. 149

7. Energy Transfer by Convection in the Atmosphere Fig. 7-4, p. 150

8. Connected Deep and Shallow Ocean Currents Fig. 7-5, p. 150

9. El Niño & La Niña (El Niño-SouthernOscillation/ ENSO) • El Niño and La Niña are the warm and cool phases of a recurring climate pattern across the tropical Pacific—the El Niño-Southern Oscillation, or “ENSO” for short. • The pattern can shift back and forth irregularly every two to seven years, and each phase triggers predictable disruptions of temperature, precipitation, and winds. • These changes disrupt the large-scale air movements in the tropics, triggering a cascade of global side effects.

10. Normal and El Niño Conditions Figure 4, Supplement 7

11. Impact of El Nino-Southern Oscillation Figure 5, Supplement 7

12. Greenhouse Gases Warm the Lower Atmosphere • Human Activities that Influence the Greenhouse Effect: • Burning fossil fuels • Clearing forests • Growing crops • The burning of fossil fuels has added more carbon dioxide to the atmosphere than can be processed by the carbon cycle as it works now • Greenhouse gases • H2O • CO2 • CH4 • N2O • Natural greenhouse effect • Gases keep earth habitable

13. Flow of Energy to and from the Earth Fig. 3-4, p. 57

14. Earth’s Surface Features Affect Local Climates • Differential heat absorption between land and water • Heat is absorbed and then released more slowly by water than by land • Rain shadow effect • Most precipitation falls on the windward side of mountain ranges • Deserts leeward • Cities create microclimates

16. 7-2 How Does Climate Affect the Nature and Locations of Biomes?

17. Climate Helps Determine Where Organisms Can Live • Biomes: large land regions with certain types of climate and dominant plant life • Not uniform • Mosaic of patches The characteristics of the patches are determined by: • Latitude and elevation • Annual precipitation • Temperature

18. The Earth’s Major Biomes Fig. 7-7, p. 153

19. North America Biomes Figure 3, Supplement 8

20. Generalized Effects of Elevation and Latitude on Climate and Biomes Fig. 7-8, p. 153

21. Natural Capital: Average Precipitation and Average Temperature as Limiting Factors Fig. 7-9, p. 154

22. There Are Three Major Types of Deserts • Tropical deserts • Temperate deserts • Cold deserts • Fragile ecosystem • Slow plant growth • Low species diversity • Slow nutrient recycling • Lack of water

23. Climate Graphs of Three Types of Deserts Fig. 7-10, p. 155

24. There Are Three Major Types of Grasslands Tropical - Savannah Temperate - Prairie Arctic – Tundra Consistently hot and dry Grazing animals Browsing animals Cold winters and hot and dry summers Tall-grass prairies Short-grass prairies Often converted to farmland Plants close to ground to conserve heat Most growth in short summer Animals have thick fur Permafrost Underground soil that stays frozen Alpine tundra above tree line in mountains

25. Climate Graphs of Tropical, Temperate, and Cold Grasslands Fig. 7-11, p. 157

26. Temperate Shrubland: Nice Climate, Risky Place to Live Chaparral • Near the sea: nice climate • Prone to fires in the dry season

27. There Are Three Major Types of Forests • Tropical • Temperate • Cold • Northern coniferous and boreal

28. Climate Graphs of Tropical, Temperate, and Cold Forests Fig. 7-13, p. 160

29. Tropical Rain Forests • Temperature – uniformly warm • High humidity – daily rain • Stratification of specialized plant and animal niches • Little wind • Rapid recycling of scarce soil nutrients

30. Niche Stratification in a Tropical Rain Forest Fig. 7-15, p. 162

31. Temperate Deciduous Forests • Temperature – moderate average temperatures that vary significantly with the seasons • Abundant precipitation that is often spread throughout the year • Broad-leaf trees • Slow rate of decomposition

32. The Four Seasons of Temperate Forests

33. Evergreen Coniferous Forests • Often called boreal forests or taigas • Sub-arctic so the winters are very cold, dry and long (often get only 6 or less hours of sun per day) • The summers are very short with cool to warm temperatures (often get 19 hours or more of sunshine) • Dominated by a few species of cone-bearing trees • Very slow decomposition • Coastal coniferous forests (temperate rain forests) • Cool temperatures with ample precipitation

35. Temperate Rain Forest in Washington State Fig. 7-16, p. 163

36. The Ecological Roles of Mountains • Contain the majority of the world’s forests • Islands of biodiversity • Habitats for endemic species • Help regulate the earth’s climate; snow and ice capped mountains reflect back a large amount of solar radiation • In winter, they are major storehouses of water so they play an important role in the hydrologic cycle