1. Solar Radiation: The driving factor•
Radiation (energy transmitted as waves, rays and particles)
released, absorbed &
reflected by all things •
travels as both a particle and
a wave •
is affected by -
gravity, magnetism, and
atmosphere composition,
distance, angle of incidence •
provides Earth with an
external source of energy

2. The sun produces most of its electromagnetic energy in intermediate wavelengths / frequencies.
True
False

3. Sources of radiation • Sun and other stars are dominant source -
Sun is closest so it has a greater influence •
Earth emits some energy as well -
Solar radiation is absorbed by Earth and
transformed into longwave radiation •
Many other planets emit radiation as well -
e.g., Jupiter and Saturn -
source is from the planet itself
not all is absorbed and re-emitted like Earth

4. The Sun • 93 million miles from Earth •
It rotates once every 600 hrs (25 days) •
Has hot spots and "cool" spots -
sunspots are relatively "cool"
Produces electro-
magnetic radiative
energy • -
concentrated in
UV, Visible &
IR spectral
classes

5. Sunspots - cyclical magnetic “storms” that occur in 11 year cycles are lower in temperature, but increase solar output.
Solar Max = lots of sunspots and increased energy output Solar Min = few to no sunspots and decreased energy output

6. Long Short Electromagnetic Spectrum (l)
Frequency (mHz) refers to vibration of particles
Wavelength (
) = distance between wave crests l

7. Position affects radiation• •
Far away=less radiation
Far away=less radiation; Closer=more radiation • •
Titled toward= more radiation
Titled away=less radiation; Tilted toward = more

8. The northern hemisphere experiences winter because the Earth is farther away from the Sun than it is during the summer months.
True
False

11. Eccentricity
100 kyr cycle
Earth’s orbit
aphelion

12. Obliquity 41 kyr cycle Axis 20 kyr ago Axis at present
Axis at 20 kyr in future
Perpendicular to the ecliptic

13. Precession of Equinox
22 kyr cycle
Conditions 11 kyr ago
sun
Earth at perihelion
Earth at aphelion
sun
Conditions now
Path of Earth’s orbit around the sun

14. Precession
22 kyr cycle

15. Milankovitch cycles- pacemaker to the ice ages*
fromO18 ice and deep sea sediment cores

16. The atmosphere acts as a mirror, prism and a trap•
Scatters some of the radiation
Ozone & dust -
why the sky is blue
prism •
Reflects some of the radiation
Dust & clouds -
clouds, snow, water etc.
mirror •
Absorbs some of the radiation
Clouds & gases -
ground, ozone, dust, etc.
trap

18. Albedo = ________________
reflected radiation
Albedo = ________________
incident radiation ･
A measure of the amount of reflected radiation ･
Some things reflect radiation better than others -
"dry" or "cold" Snow & Ice = high albedo -
water = moderate for visible, low for infrared -
plants= moderate for visible ･
Land absorbs and releases radiative energy
quicker than water

19. Albedo of land surfaces on Earth
Warm colors are higher; cool are lower; white no data available
Data collected by NASA’s MODIS satellite, April 2002

20. IR output from Earth K

21. Effects of cloud type on radiation budget•
different types of interference have
different effects on Earth's energy budget