Radiation and Energy Balance (3)

Question 1

What are the waves on the electromagnetic spectrum?

Answer 1

gamma-rays
x-rays
ultraviolet
infrared
microwaves
radio

Question 2

Most visible colour?

Answer 2

red

Question 3

Least visible colour?

Answer 3

violet

Question 4

What are waves in terms of electromagnetic waves?

Answer 4

The waves are oscillating electric and magnetic fields that can propogate (travel) in a vacuum.

Question 5

How do you calculate frequency?

Answer 5

Speed of light divided by wavelength.

Question 6

What is earth’s climate system ultimately driven by?

Answer 6

Solar energy

Question 7

How does solar energy travel?

Answer 7

From the sun through the vacuum of space in the form of waes called electromagnetic raiation.

Question 8

What is the type of solar radiation that heats the earth’s surface?

Answer 8

Mostly visible light and solar infrared with a bit of ultraviolet.

Question 9

Where is most of the incoming ultraviolet absorbed?

Answer 9

By ozone in the stratosphere

Question 10

What does a glass prism do to light?

Answer 10

Refracts (bends) the different wavelengths (colours) of sunlight by different angles and hence separates the incoming beam according to wavelength.

Question 11

The analysis of radiation by wavelength or frequency is called:

Answer 11

spectroscopy

Question 12

What are the two types of infrared radiation?

Answer 12

Solar infrared and terrestrial infrared

Question 13

What is solar infrared?

Answer 13

Emitted by the sun. Makes up nearly half of the solar radiation. (the other half is mostly visible light)

Question 14

What is terrestrial infrared?

Answer 14

Emitted by the earth’s surface and atmosphere. Strongly absorbed and emitted by greenhouse gases and clouds in the atmosphere.

Question 15

Which electromagnetic waves can transmit through the earth’s cloudless atmosphere?

Answer 15

Near UV, visible, some infrared, some microwave and some radio.

Question 16

The higher the temperature, the shorter the wavelength of maximum emission.

Answer 16

All bodies emit electromagnetic radiation. The type or wavelength of the radiation emitted depends on its temperature.

Question 17

What is a ‘black body’?

Answer 17

If the efficiency is 100% (to emit and absorb radiation), then the material is called a black body and the raditation is called black body radiation or the black body spectrum.

Question 18

Are gases black bodies?

Answer 18

No, they emit and absorb at very specific wavelengths so they can’t be.

Question 19

what is a closed system?

Answer 19

There are no exchanges of energy or mass with the surroundings?

Question 20

Is the earth a closer or open system?

Answer 20

An open system because radiant energy and a little bit of mass can enter and leave the system.

Question 21

What does an albedo of 1.0 mean?

Answer 21

That all the incoming radiation is reflected.

Question 22

What does an albedo of 0.0 mean?

Answer 22

That no radiation is reflected, it is all absorbed.

Question 23

What is the average planetary albedo of earth?

Answer 23

0.30

Question 24

Clouds and deserts reflect most of the sunlight while oceans and forests…

Answer 24

absorb most of it.

Question 25

What are the three factors that determine the planetary averaged surface temperature?

Answer 25

1. Flux of incoming solar radiation
2. Albedo of the earth
3. Greenhouse factor.

Question 26

What are three ways of increasing the global averaged surface air temperature?

Answer 26

1. Increase the amount of solar radiation arriving at the top of the atmosphere
2. Decrease the planetary albedo
3. increase the greenhouse factor so that more infrared radiative energy is transferred