1. Chapter 6. Biogeography: Climate, Biomes and Terrestrial Biodiversity Living in the Environment Miller’s 13 th Edition

2. www.wral.com/weather

3. What is weather? Short-term set of physical properties of the troposphere at a particular place and time. Temperature Temperature Pressure Pressure Humidity Humidity Precipitation Precipitation Sunshine Sunshine Cloud cover Cloud cover Temperature Temperature Pressure Pressure Humidity Humidity Precipitation Precipitation Sunshine Sunshine Cloud cover Cloud cover

4. What are Highs and Lows? HighHigh –Air mass with high pressure –Cool, dense air descends toward the earth’s surface and becomes warmer LowLow –Air mass with low pressure –Less dense warm air spirals inward –The center of a low rises, and its warm air expands and cools LowLow –Air mass with low pressure –Less dense warm air spirals inward –The center of a low rises, and its warm air expands and cools changes in atmospheric pressure

5. Highs and Lows

6. Weather Extremes TornadoesTornadoes Tropical cyclonesTropical cyclones  Atlantic Ocean = hurricanes  Pacific Ocean = typhoons

7. Descending cool air Severe thunderstorm Tornado forms when cool downdraft and warm updraft of air meet and interact Rising warm air Severe thunderstorms can trigger a number of smaller tornadoes Rising updraft of air

8. Rising winds exit from the storm at high altitudes. The calm central eye usually is about 24 kilometers (15 miles) wide. Moist surface winds spiral in towards the center of the storm Gales circle the eye at speeds of up to 320 kilometers (200 miles) per hour. Tropical Cyclones

9. Risk of Tornadoes Highest High Medium Low Tropical Cyclone Frequency High Moderately high Gulf of Alaska Prince William Sound CANADA UNITED STATES Grand Banks Atlantic Ocean MEXICO

10. Climate the average weather patterns for an area over a long period of time (30 - 1,000,000 years). is It is determined by Average Precipitation Average Temperatureand which are influenced by latitudealtitudeocean currents and affects where people livehow people live what they grow and eat Climate and and its its effects effects

11. Global Air Circulation Patterns Result In: 1)Uneven heating of the earth’s surface. 2)Seasonal changes in temperature and precipitation. 3)Rotation of the earth on its axis Deflect windsDeflect winds  Six convection cells (3N/3S)

12. Climate type Cold Cool Temperate Warm Temperate Tropical (equator) Tropical Warm Temperate Cool Temperate Cold

13. Fall (sun aims directly at equator) Summer (northern hemisphere tilts toward sun) Spring (sun aims directly at equator) 23.5º Winter (northern hemisphere tilts away from sun) Solar radiation

14. Initial pattern of air circulation Deflections in the paths of air flow near the earth’s surface 30°S Easterlies Westerlies Southeast tradewinds (Doldrums) Northeast tradewinds Westerlies (from the west) Easterlies (from the east) 60°S equator 30°N 60°N © 2004 Brooks/Cole – Thomson Learning

15. Global Air Circulation Patterns Result In: 4)Long term variation in the amount of solar energy Wobbles and tilts about the earth’s axis.Wobbles and tilts about the earth’s axis. 5)Properties of air and water Convection Cells – circulate air, heat, and moisture both vertically and from place to place.Convection Cells – circulate air, heat, and moisture both vertically and from place to place.

16. Cell 3 South Cold, dry air falls Moist air rises — rain Cell 2 South Cool, dry air falls Cell 1 South Moist air rises, cools, and releases moisture as rain Cell 1 North Cool, dry air falls Cell 2 North Moist air rises — rain Cell 3 NorthCold, dry air falls Polar cap Arctic tundra 60° 30° 0° 30° 60° Polar cap Evergreen coniferous forest Temperate deciduous forest and grassland Desert Tropical deciduous forest Equator Tropical rain forest Tropical deciduous forest Desert Temperate deciduous forest and grassland Relationship between global air circulation and biomes

17. Warm current Cool air Convection cell Cool current Warm air Equator Solar radiation Warm water Warm current Polar front Cool current Cold water Ocean Currents Surface Currents Midlevel currents Bottom Currents

18. Polar (ice) Subarctic (snow) Cool temperate Warm temperate Dry Tropical Highland Major upwelling zones Warm ocean current Cold ocean current River

19. Wind Movement of surface water Diving birds Nutrients Upwelling Fish Zooplankton Phytoplankton A shore upwelling

20. What is the El Nino-Southern Oscillation (ENSO)? 1)Occurs in the Pacific Ocean 2)Prevailing westerly winds weaken or cease 3)Surface water along the South and North America coasts become warmer 4)The normal upwelling of cold, nutrient rich water are suppressed

21. Normal Conditions Cold water Warm water Thermocline SOUTH AMERICA Warm waters pushed westward AUSTRALIA EQUATOR Surface winds blow westward

22. El Niño Conditions Cold water Thermocline Warm water Warm water deepens off South America SOUTH AMERICA Warm water flow stopped or reversed AUSTRALIA EQUATOR Drought in Australia and Southeast Asia Winds weaken, causing updrafts and storms

23. El Niño Unusually warm periods Unusually high rainfall Drought

24. the greenhouse effect 1)Water vapor H 2 O 2)Carbon dioxide CO 2 3)Methane CH 4 4)Nitrous oxide N 2 O 5)Chlorofluorocarbons CFCs Major Greenhouse Gases

25. a Winds carry moisture inland from Pacific Ocean b Clouds, rain on windward side of mountain range c Rain shadow on leeward side of mountain range Moist habitats Dry habitats the rain shadow effect

26. Rain Shadow Effect