Lec 4 - Solar Radiation, Orbital-Scale CC

Question 1

What determines the amount of shortwave radiation received?

Answer 1

1. location
2. time of year

Question 2

What are the two fundamental motions of the Earth?

Answer 2

1. spins on its axis once a day
2. revolves around sun once a year

Question 3

How does our distance to the Sun change throughout the year?

Answer 3

Perihelion: closest position to the sun
Aphelion: farthest position to the sun

• distance to the sun changes the value of the solar constant!!

Question 4

What angle is the Earth’s axial tilt?

Answer 4

23.5 degrees

Question 5

How does location affect the amount of solar radiation received?

Answer 5

• spreading of beam

Question 6

What orbital parameters affect climate?

Answer 6

• axial tilt
• eccentricity of orbit
• timing of equinoxes

Question 7

What effect does a changing axial tilt have?

Answer 7

alters the strength of the seasons

Question 8

What 3 orbital precessions occur?

Answer 8

• axial precession
• precessions of the ellipse
• precession of the equinoxes

Question 9

How does absorption of radiation alter climate?

Answer 9

• atmospheric heating
• amount of energy transferred to surface

Question 10

What are the two kinds of scattering that happen to light in the atmosphere?

Answer 10

• Rayleigh scattering: small molecules, scatter short wavelengths (blue)
• Mie scattering: large scattering agents, large aerosols, directed scattering that stretches wavelengths (warmer colours)

Question 11

What is the transmission of light?

Answer 11

percentage of energy transmitted through the atmosphere the surface

Question 12

What is the fate of most radiation that encounters our atmosphere?

Answer 12

• absorption by surface
• absorption by gases/clouds
• reflection by cloud
• 30% reflected by atmosphere/clouds/atmosphere