Energy Relationships and the Biosphere

1. Energy Relationships and the Biosphere Section 2.1

2. The Electromagnetic Spectrum • The sun emits electromagnetic radiation. • The electromagnetic spectrum shows us all the different wavelengths within the sun’s radiation.

3. Insolation & Angle of Inclination • Insolation: The amount of solar energy received by a region of the Earth’s surface. • Angle of Inclination: Refers to the degree of the earth’s tilt. 23.5° • The angle of inclination affects the insolation. • The angle points the northern hemisphere towards the sun in June. • The angle points the northern hemisphere away from the sun in December.

4. Latitude: Imaginary lines that run parallel to the equator. North & South poles are at 90° latitude Equator is at 0° latitude The tilt of the Earth paired with the rotation around the sun causes a variation in seasons. Angle of Inclination & the Seasons

6. Solstice & Equinox Spring Equinox Winter Solstice Summer Solstice Fall Equinox

7. Solstice: One of two point’s in the Earth’s orbit at which the poles are most tilted towards or away from the sun. Equinox: One of two points in the Earth’s orbit when the number of daylight hours is equal to the number of hours of night. Solstice & Equinox

8. Solstice & Equinox Spring Equinox Winter Solstice Summer Solstice Fall Equinox

9. Insolation & Angle of Incidence • The angle between a ray falling on the surface and the line perpendicular to that surface. • The angle of incidence determines how much solar energy an area receives. • Higher latitudes receive less solar energy than equatorial latitudes.

10. Insolation & Angle of Incidence Less perpendicular Lesslight more spread out Almost perpendicular Direct hit more light

11. Insolation & Angle of Incidence

12. Absorption • All four layers of the atmosphere absorb incoming radiation from the sun. • N2 and O2 in the mesosphere, thermosphere and stratosphere absorb gamma and X-rays. • Ozone in the stratosphere absorbs UV radiation • CO2, H2O in the troposphere absorb infrared (heat) • Visible light + Radio Waves make it through to the earth’s surface.

13. Albedo • Reflected solar radiation. • Light shades and shiny surfaces reflect radiant energy • Dark shades and dull surfaces absorb radiant energy • Earth’s albedo is 30% (not spread evenly throughout the planet)

14. Albedo

15. Net Radiation Budget • Not all incoming radiation is absorbed • Some is re-emitted as thermal energy • The net-radiation budget is the difference between the incoming radiation and the outgoing radiation • Incoming radiation is all of the radiation that reaches the surface of the Earth • Outgoing radiation refers to that which is emitted from the Earth’s surface and atmosphere

16. Trends in Radiation • Incoming Radiation – Outgoing Radiation = Net Radiation Budget • Poles – low insolation and high albedo results in a net radiation deficit. • Equator – High insolation and low albedo results in a net radiation surplus.

17. The Natural Greenhouse Effect • Greenhouse gases (GHGs) in our atmosphere trap in heat radiated from earth. • GHGs: water vapour, carbon dioxide, nitrous oxides and methane. • Without the greenhouse effect, earth would be covered completely with ice.

18. http://www.youtube.com/watch?v=oJAbATJCugs&feature=fvw • http://www.youtube.com/watch?v=dP-tg4atr5M • http://www.youtube.com/watch?v=_7nv8iDZ_-0&feature=PlayList&p=6E67B6A2BC1ED106&playnext=1&playnext_from=PL&index=48 • http://www.youtube.com/watch?v=8Y50CF3R7zc