Exam 1 Concepts

Question 1

Units of monochromatic (or spectral) irradiance

Answer 1

Wm^(-2)μm^(-1)

Question 2

Units of monochromatic (or spectral) radiance

Answer 2

Wm^(-2)μm^(-1)str^(-1)

Question 3

Another term for flux density

Answer 3

Irradiance

Question 4

Another term for intensity

Answer 4

Radiance

Question 5

Mathematical definition (formula) for a solid angle

Answer 5

Ω = surface area/r^2 (in stradians)

Question 6

What does the Poyting vector tell us?

Answer 6

It tells us what direction and magnitude the electromagnetic radiation energy is travelling away from the source.

Question 7

What is the speed of x-rays in a vacuum?

Answer 7

Speed of light: 3.00*10^8 m/s

Question 8

What is the speed of UV radiation in a vacuum?

Answer 8

Speed of light: 3.00*10^8 m/s

Question 9

What is the speed of radio waves in a vacuum?

Answer 9

Speed of light: 3.00*10^8 m/s

Question 10

In terms of sine and cosine, what does e^(iθ) equal?

Answer 10

e^(iθ) = cos(θ) + isin(θ)

Question 11

Most energetic to the least energetic in the electromagnetic spectrum

Answer 11

Gamma rays, x-rays, UV rays, Visible, IR, Microwaves, Radio (Great Xanax Universally Visualizes Imaginary Monkeys Running)

Question 12

What is the fraction of the solar output for Visible light?

Answer 12

39%

Question 13

What is the fraction of the solar output for Thermal IR?

Answer 13

0.9%

Question 14

What is the fraction of the solar output for UV-A?

Answer 14

6.2%

Question 15

What is the fraction of the solar output for Near IR?

Answer 15

52%

Question 16

What atmospheric processes is the Visible region associated?

Answer 16

Mostly transparent atmosphere

Question 17

What atmospheric processes is the Thermal IR region associated?

Answer 17

Absorbed by water vapor

Question 18

What atmospheric processes is the X-rays region associated?

Answer 18

Photoionizes all species; upper absorbed atmosphere

Question 19

What atmospheric processes is the Extreme UV region associated?

Answer 19

Photoionizes O2 and N2; absorbed at 90 km

Question 20

What atmospheric processes is the Far UV region associated?

Answer 20

Photodissociates O2; absorbed at 50 km

Question 21

Write the Eulerian representation of plane harmonic waves (the general formula for a plane harmonic wave, not an EM specific solution)?

Answer 21

e^[i(kx-ωt)]

Question 22

What is the meaning of I/βa

Answer 22

The distance needed to be traveled for the wave’s energy to be attenuated e^(-1) (approximately 37%) of its original.

Question 23

What is the mathematical relationship (formula) relating frequency and angular frequency?

Answer 23

ω = 2πr
where ω = angular frequency
r = frequency

Question 24

What is the plane wave solution for a complex electric field using the complex wave vector?

Answer 24

Evector = Enotexp[i(kvector*xvector + ωt)]

Question 25

What are the three major differences between classical physics and modern physics?

Answer 25

1. Classical physics is deterministic, while modern physics is probabilistic. 2. Classical physics has continuous energy levels, while modern physics has discrete energy levels. 3. In classical physics, a wave is a wave and a particle is a particle. In modern physics, a wave can have particle-like properties and a particle can have wave-like properties.

Question 26

What is the importance of EM radiation in weather and climate forecast models?

Answer 26

Electromagnetic radiation is constantly/continuously flowing through our atmosphere, making it imperative for our weather and climate models. Diabatic heating on nonlocal processes, also can cause issues calculating atmospheric conditions using radiation.

Question 27

What are three main assumptions of classical physics (I gave you six)?

Answer 27

1. Determinism: If you know the whereabouts of a molecule at time t, you can figure out where it will be in the past or present. 2. The properties of light are verified through Maxwell's electromagnetic wave theory. 3. A wave and a particle can only exist on their own. A wave is a wave, and a particle is a particle.

Question 28

For what did Einstein win the Nobel Prize in Physics?

Answer 28

His paper on the Photoelectric Effect in 1905.

Question 29

Choose two of Maxwell's equations for electromagnetic radiation and give a written (not formula) description of those two equations. As an example: The divergence of the Sasquatch field is equal to the negative of the time rate of change of the curl of the Loch Ness Monster field.

Answer 29

1. The divergence of the electric displacement equals the density of electric charge. 2. The divergence of the magnetic induction equals zero. 3. The voltage accumulated around a closed circuit is proportional to the time rate of change of the magnetic flux it encloses. 4. Electric circuits and changes in electric fields are proportional to the magnetic field circulating about the area they pierce.