Climate and Biomes

1. Climate and Biomes AP Environmental Science Mark Ewoldsen, Ph.D. and Michael Zito www.ai.mit.edu/people/jimmylin/pictures/2001-12-seattle.htm

2. Atmosphere, Climate and Biomes • The Atmosphere • Origin of Modern Atmosphere • Structure • Composition • Energy Budget • Climate • Air and Ocean Circulation • El Nino and La Nina • Biome Distribution

3. Origin of Modern Atmosphere • original atmosphere surrounded the homogenousplanet Earth and probably was composed of H and He • second atmosphere evolved from gases from molten Earth • H2O, CO2, SO2, CO, S2, Cl2, N2, H2, NH3, and CH4 • allowed formation of oceans and earliest life • modern Atmosphere • evolved after Cyanobacteria started photosynthesizing • oxygen produced did not reach modern levels until about 400 million years ago www.degginger.com/digitalpage.html

4. Composition • Nitrogen (N2, 78%) • Oxygen (O2, 21%) • Argon (Ar, 1%) • myriad of other very influential components are also present which include the Water (H2O, 0 - 7%), "greenhouse" gases or Ozone (O3, 0 - 0.01%), Carbon Dioxide (CO2, 0.01-0.1%),

5. Earth’s Atmosphere • compared to the size of the Earth (104 km), the atmosphere is a thin shell (120 km). http://www.gsfc.nasa.gov/gsfc/earth/pinatuboimages.htm

6. AtmosphereLayers • Exosphere • Thermosphere • (Ionosphere) • Mesosphere • Stratosphere • Troposphere

7. Troposphere • 8 to 14.5 kilometers high (5 to 9 miles) • most dense • the temperature drops from about 17 to -52 degrees Celsius • almost all weather is in this region

8. Stratosphere • extends to 50 kilometers (31 miles) high • dry and less dense • temperature in this region increases gradually to -3 degrees Celsius, due to the absorption of ultraviolet radiation • ozone layer absorbs and scatters the solar ultraviolet radiation • ninety-nine percent of "air" is located in first two layers • every 1000-m 11% less air pressure

9. Distribution of Biomes

10. Energy emitted from sun (Kcal/cm2/min) 15 10 Visible 5 Ultraviolet Infrared 0 0.25 1 2 2.5 3 Wavelength (micrometers) Sun High energy, short wavelength Low energy, long wavelength Nonionizing radiation Ionizing radiation Far ultraviolet waves Near ultraviolet waves Near infrared waves Far infrared waves Cosmic rays Gamma rays TV waves Radio waves Visiblewaves X rays Microwaves 10-14 10-12 10-8 10-7 10-6 10-5 10-3 10-2 10-1 1 Wavelength in meters (not to scale) • Radiation and The Electromagnetic Spectrum

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

13. Climate • Climate Factors: • Air temperature • Air pressure • Cloud cover • Precipitation • Winds

14. Air Temperature • Solar energy is more concentrated (J/km2) at the equator than at the poles • As a result, equatorial regions heat up more than the poles. • Warm air and water at the equator travel poleward while cold air and water at the poles travel equatorward in an attempt to equalize this temperature contrast. • It is the atmosphere's continual struggle for temperature balance that brings us our changing weather.

15. http://www.usatoday.com/weather/tg/wglobale/wglobale.htm

16. Types of Heat Transfer Convection Conduction Radiation Heat from a stove burner causes atoms or molecules in the pan’s bottom to vibrate faster. The vibrating atoms or molecules then collide with nearby atoms or molecules, causing them to vibrate faster. Eventually, molecules or atoms in the pan’s handles are vibrating so fast it becomes too hot to touch. Heating water in the bottom of a pan causes some of the water vaporize into bubbles. Because they are lighter than the surrounding water, they rise. Water then sinks from the top to replace the rising bubbles. This up and down movement (convection) eventually heats all of the water. As the water boils, hear from the hot stove burner and pan radiate into the surrounding air, even though air conducts very little heat.

17. Cell 3 North Cold, dry air falls Moist air rises — rain Polar cap Cell 2 North Arctic tundra Evergreen coniferous forest 60° Cool, dry air falls Temperate deciduous forest and grassland Cell 1 North Desert 30° Moist air rises, cools, and releases moisture as rain Tropical deciduous forest Tropical rain forest 0° Equator Tropical deciduous forest 30° Cell 1 South Desert Temperate deciduous forest and grassland Cool, dry air falls 60° Cell 2 South Polar cap Cold, dry air falls Moist air rises — rain Cell 3 South • Convection cells: Equalizing Earth's Energy Imbalance • Animation 1 • Animation 2

18. Air Pressure • air pressure is caused by the weight of the air pressing down on the Earth, the ocean and on the air below • the pressure depends on the amount of air above the measuring point and falls as you go higher • air pressure changes with weather

20. … and Weather • air in a high pressure area compresses and warms as it descends • the warming inhibits the formation of clouds, meaning the sky is normally sunny in high-pressure areas • haze and fog might form • the opposite occurs in an area of low pressure

21. LOW PRESSURE HIGH PRESSURE Heat released radiates to space Condensation and precipitation Cool, dry air Rises, expands, cools Falls, is compressed, warms Warm, dry air Hot, wet air Flows toward low pressure, picks up moisture and heat HIGH PRESSURE Moist surface warmed by sun LOW PRESSURE HIGH PRESSURE LOW PRESSURE

22. Winds • horizontal wind moves from areas of high to low pressure • speed is determined by differences in pressure • Coriolis effect causes winds to spiral from high pressure zones and into low pressure zones www.iiasa.ac.at/Admin/INF/OPT/ Spring98/feature_story.htm

23. 60ºN Cold deserts Westerlies Forests 30ºN Northeast trades Hot deserts Forests 0º Equator Hot deserts Southeast trades 30ºs Forests Westerlies Cold deserts 60ºS

24. On the windward side of a mountain range, air rises, cools, and releases moisture. On the leeward side of the mountain range, air descends, warms, and releases little moisture. Prevailing winds pick up moisture from an ocean. Dry habitats Moist habitats The Rain Shadow Effect

25. Major Ocean Currents

26. Distribution of Biomes

27. Temperature, Precipitation and Biomes

28. Identify the Biome Place La Selva, Costa Rica Marietta, Ohio Pasadena California Ferron, Utah Tucson, Arizona Santa Rosa, Costa Rica Brazzaville, Congo Lambarene, Gabon Amauulu, Hawaii Toolik Lake, Alaska Beijing, China Seoul, South Korea Archbold Biological Station Everglades National Park (Flamingo) Avg Temp oC 22.1 12 18.2 8.8 21.1 26 25 25.7 20 -8.8 11.8 11.2 29.1 28.1 Annual Precipitation (cm) 403 105 51.8 20.9 21.9 165 137 195 410 18 63.5 137 131 159 Source: http://www.marietta.edu/~biol/biomes/biome_main.htm

29. Tropical rain forest (Manaus, Brazil) A Typical Climatogram

30. Altitude Mountain Ice and snow Tundra (herbs, lichens, mosses) Coniferous Forest Latitude Deciduous Forest Tropical Forest Tropical Forest Deciduous Forest Coniferous Forest Tundra (herbs, lichens, mosses) Polar ice and snow

31. El Nino – Typical surface ocean circulation

32. El nino conditions • Normal • El nino – strong counter-current

33. El Nino: Normal Conditions • Prentice Hall Textbook animation link

34. El Nino: El Nino Development • Prentice Hall Textbook animation link

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

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

37. El Nino: La Nina • Prentice Hall Textbook animation link

38. El Nino – weak Aleutian High

39. La Nina – strong Aleutian High

40. El nino - precipitation

41. El nino - precipitation