Seasons and Insolation

1. Seasons and Insolation

2. Why we care:1. Energy from the Sun Drives: • Global wind patterns • Ocean currents • Water cycle • Plant processes- photosynthesis • Weather weathering and erosion *maximum intensity of radiation occurs in range of visible wavelengths of EM

3. First Method of Energy Transfer There are no particles between the Sun and the Earth so energy CANNOT travel by conduction or by convection. It does not require a medium. Radiation: energy moves through empty space at the speed of light

5. 2. Insolation- received by outer atmosphere INcomingSOLarradiATION *radiation received from the sun is most intense during the summer (June 21) During the Day MAX= noon (12 pm) MIN = 6 AM or 6 PM

6. What Happens to Insolation when it reaches our atmosphere?

7. 3. What happens when energy hits an object? • Transmission • Clear glass • Reflection • Energy bounces at an angle equal to the angle of incidence Reflection vs. scattering: • Bounce off. Reflected rays are direct While scattered rays go in all directions • Refraction- light rays bend as they pass through a material -Prism (rainbows), ruler in a beaker

8. 4. Absorption of Ultraviolet by Ozone • Most UV rays are absorbed by Ozone 03 • Ozone protects life from harmful radiation

9. 5. Absorption of Longwave (infrared) radiation by atmosphere • Greenhouse gasses trap infrared radiation • Greenhouse Gasses • Carbon Dioxide • Methane • Water Vapor • Nitrous Oxide

10. 6. Insolation: Scattering and Reflection by Clouds and dust

12. 7. Factors effecting absorption and reflection of Insolation • Angle of Incidence • Surface Characteristics • Change of state

13. Angles of Insolation • Making Angles Dec. 21 March 21 June 21 25.5 ° + 23.5 ° _______ _______ Low High Temp Temp

14. Base your answers to this question on the diagram below, which shows the tilt of Earth on its axis in relation to the Sun on one particular day. Points A through E are locations on Earth’s surface. Point D is located in New York State. The dashed line represents Earth’s axis.Which diagram best represents the angle of the Sun’s rays received at location C at noon on this day?

15. Absorption- energy is taken into the material and temperature can increase • A good absorber is a good radiator of heat and vice versa • An example of a good absorber and radiator is asphalt/roads- dark and bumpy • An example of a bad absorber and radiator is a mirror, snow, ice- light and smooth

16. Surface Characteristics • Light, & Smooth reflects • Dark & Rough Absorbs

17. The diagram below shows the percentage of sunlight reflected by different Earth surfaces when the Sun is directly overhead. What material reflects the least sunlight? • Forest • Beach • Ocean • Snow

18. 8. Land and Water Heating Land heats up quicker during the day because it has a lower specific heat Water retains heat during the day because it has a higher specific heat

19. Land vs. Water Heating On a clear summer day, the surface of land is usually warmer than the surface of a nearby body of water because the water • Receives less insolation • Reflects less insolation • Has a higher density • Has a higher specific heat

20. 9. What causes global warming? • Some gases absorb insolation, they make the atmosphere warmer • These gases, which act like a blanket, are referred to as ‘greenhouse gases’. They include methane CH4, carbon dioxide CO2, water vapor H2Ov, CFCs

22. 11. On planet Earth the temperature is 30 C/50 F higher than it would be without these gases. At these temperatures liquid water can exist life On planet Venus, these gases cause the temperature to be VERY hot. -dense atmosphere of CO2 -average surface temp- 460 C 5. When we increase CO2 by burning fossil fuels or cutting down trees, there is an increase in temperature.

23. January 2010 Regents

24. 11. Variation of Insolation and temperature • As duration increases, temperature increases • As latitude increases, temperature decreases

25. Latitude and Insolation IntensityHigh Latitude= Low Intensity

26. The table below shows the latitude and the average yearly temperature for four different cities. • Jan 2010

27. Duration of Insolation • Summer= Greater Duration in USA • Longer Duration = Generally Warmer Temperatures

28. Times of Yearly Maximum and Minimum Temperatures • What month is the coldest? • Why? • What month is the hottest? • Why?

30. 12. Maximum temperature is in Late July • Maximum temperature is after maximum duration of insolation • More energy gained than lost daily until late July…Heat gets put in the bank and temperatures rise!

31. 13. Why is the hottest time of day around 2 pm?Coolest at 6 am

32. 14. Heat Budget and Climate Change • Heat Budget- Balance between energy received and lost • Heat Surpluss (extra heat)= global warming • Heat Deficit= global cooling (Ice Age)

34. 15. Natural Causes of Climate Change • Changes in Solar Energy • Changes in Earth’s Orbit and Tilt • Volcanic Eruptions • Human Causes

35. Changes in Solar Energy • Sun Spots/Solar Storms • Lots of Sunspots= more insolation

36. Earth’s Orbit and Axis Tilt

37. Volcanic Eruptions

38. Human Causes

40. Main source of heat for the atmosphere? EARTH!! But why?? • INcoming SOLar RadiATION (insolation) mostly passes through atmosphere and heats Earth’s surface • Earth reradiates energy as heat (infrared radiation) • Heat absorbed by atmospheric gases - Greenhouse gases = carbon dioxide, water vapor, etc.