1. Weather World Geography Notes 1.5

2. Atmosphere Atmosphere is a thin layer of gases This protects the surface from Temperature extremes (acts as insulation) Space debris Dangerous radiation Gravity holds Earth’s atmosphere

3. Nearly all atmospheric gases are contained within around 20 miles of Earth Weather occurs within 10 miles

4. Composition Oxygen and Nitrogen make up 99% of dry air This excludes water vapor Nitrogen comprises 78% of the atmosphere Oxygen comprises 21% of the atmosphere Vital to respiration Active agent in weathering

5. Weather and climate are not affected much by nitrogen or oxygen. The variable gases that are most important to weather and climate are: Water vapor Carbon dioxide

6. Water vapor is the most variable: May make up.1% to 4% of the lower atmosphere’s volume It is affected by: Exposed surface water Atmospheric temperature Altitude Water vapor is critical in: The process of condensation and precipitation Transporting heat around the world through latent heating

7. Carbon dioxide is the other very important gas in weather and climate. On average makes up.035% of the atmosphere Carbon dioxide levels decrease in the summer when plants turn it to oxygen and carbon Carbon dioxide and other gases play an important part in the greenhouse effect Which heats the Earth

8. In addition to gases, Earth’s atmosphere also contains aerosols and particulates. From natural and industrial processes Light enough to stay suspended in the air Can significantly affect weather and climate Can reduce the amount of energy Earth receives from the sun Can lead to short term global cooling Also can act as nuclei for condensation of cloud droplets

9. Pollution These aerosols, particulates, and atmospheric gases become pollutants when: Their concentrations increase to levels that threaten the health of living things Substantially change existing atmospheric conditions

10. Earth’s Radiation Balance Earth maintains a radiation balance: Energy coming from the sun must eventually be equaled by energy radiated and reflected from Earth. This process helps explain weather patterns

11. Solar Radiation There are different types of radiation that are identified by their wave length The distance between wave crests Visible light ranges in wavelength 0.4 microns to 0.7 microns

12. Insolation Insolation is a stream of radiant energy Only about 52% passes through the atmosphere to reach Earth’s surface. The atmosphere: absorbs (~23%), reflects (~17%), and scatters (~8%) Reflection of insolation is determined by an objects albedo (reflectivity)

13. On average about 52% of insolation reaches Earth’s surface where it is: Reflected or Absorbed and converted to kinetic energy This creates and moves weather Albedo can range from 3% to 95% Water has an albedo of 3% to 10%, but has a higher albedo as it approaches the poles (nearly 100% in some cases)

14. Global Radiation Balance

15. Heat and Temperature

16. Greenhouse Effect

17. Vertical Temperature Change

18. Diurnal and Seasonal Temperature Patterns

19. Spatial Temperature Patterns

20. Temperature and Humans

21. Atmospheric Pressure and Winds

22. Atmospheric Pressure

23. Altimeters

24. Pressure Variations

25. Patterns of Atmospheric Pressure

26. Wind

27. Wind Speed

28. Local and Regional Winds

29. Monsoons

30. Global Winds and Ocean Currents

31. Weather Systems