Chapter 2 -- Notes

Question 0

Define Perihelion

Answer 0

When the earth is closest to the sun, around January 3

Question 1

Define Temperature

Answer 1

The measure of the average kinetic energy of the atoms, or molecules, in a substance. (Note: temperature is not a measure of the total kinetic energy of the particles within a substance.)

Question 2

Define Aphelion

Answer 2

When the earth is farthest away from the sun, around July 6.

Question 3

Define Plane of the ecliptic.

Answer 3

The plane the Earth orbits around the sun.

Question 4

Define Inclination of the axis

Answer 4

It means that the earth tilts at a 23 1/2° angle.

Question 6

Define Tropic of Cancer.

Answer 6

A line of latitude 23 1/2° (equal to the axis tilt) north of the equator, it is here that on June 21 or 22 the suns vertical rays strike.

Question 6

Where do the vertical rays from the sun strike during the autumn and spring equinoxes.

Answer 6

The equator

Question 7

Define Tropic of Capricorn

Answer 7

A line of latitude 23 1/2° (equal to the axis tilt) south of the equator, it is here that on December 21 or 22 the suns vertical rays strike.

Question 8

Define Circle of illumination

Answer 8

The boundary separating the dark half of the earth from the lighted half.

Question 9

When is the longest day of the year in the Northern Hemisphere? When is the shortest? (Opposite for Southern Hemisphere)

Answer 9

Summer solstice. Winter solstice.

Question 10

True or false: The farther north a location is from the equator, the longer the period of daylight until the Arctic Circle is reached, where the length of daylight becomes 24 hours long. (opposite for the Southern Hemisphere)

Answer 10

True

Question 11

During an equinox the length of daylight is _____ everywhere on earth because the circle of illumination passes directly through the poles, thus dividing the latitudes in half.

Answer 11

12 hours

Question 12

Name the three ways the flow of energy can occur, and define them.

Answer 12

Conduction, the transfer of heat through electron and molecular collisions from one molecule to another.
Convection, heat transfer that involves the actual movement or circulation of a substance
Radiation, the only mechanism of heat transfer that travels thru the vacuum of space

Question 13

Define thermals.

Answer 13

Parcels of rising air due to convection.

Question 14

What is the difference to convection and advection?

Answer 14

Convection, the part of the atmospheric circulation that involves upward and downward.
Advection the horizontal component of convective flow, more commonly known as wind.

Question 15

List the waves in shortest wavelength to longest.

Answer 15

Gamma rays, x-rays, ultraviolet (responsible for sunburn), visible, infrared (heat), radio.

Question 16

Surfaces that are good absorbers of all wavelengths of visible light appear _____ in color, whereas ______ colored surfaces have much lower absorptivity.

Answer 16

Black, Light

Question 17

Name the laws of radiation

Answer 17

1. All objects continually emit radiant energy over a range of wavelengths.
2. Hotter objects radiate more total energy per unit area than do colder objects.
3. Hotter objects radiate more energy in the form of short wavelength radiation than do cooler objects.
4. Objects that are good absorbers of radiation are good emitters.

Go to page 49! (while you’re there look at figure 2–13)

Question 18

The fraction of radiation that is reflected by an object.

Answer 18

Albedo

Question 19

What is the earth’s albedo?

Answer 19

30% or 0.3

Question 20

How much of solar radiation absorbed at the earth’s surface is scattered light?

Answer 20

Over one half.

Question 21

What does it mean if there’s a red sunset

Answer 21

That there are numerous small particles in the atmosphere.

Question 22

What does it mean when there’s a white sky?

Answer 22

That there are numerous large particles in the sky.

Question 23

The bluer the sky the ______ the air.

Answer 23

Cleaner

Question 24

The ________ is nearly transparent to incoming solar radiation and that direct solar energy is not ineffective heater of Earth’s atmosphere.

Answer 24

Atmosphere

Question 25

Define the greenhouse effect.

Answer 25

The extremely important role the atmosphere plays in heating the earth’s surface. A significant fraction of the longwave radiation emitted by the Earth’s land-sea surface is absorbed by water vapor, carbon dioxide, and other trace gases in the atmosphere. Which increases the amount of energy radiated from the atmosphere back to the earth surface and then repeats.

Question 26

True or false: There is a zone around earth between 38°N and 38°S that receives more solar radiation than is lost to space.

Answer 26

True. The opposite is true for higher latitudes, where more heat is lost through radiation emitted by earth than is received from the sun.

Question 27

Define Albedo.

Answer 27

The reflectivity of a substance, usually expressed as a percentage of the incident radiation reflected.

Question 28

Define Wien’s displacement law.

Answer 28

The intensity of radiation from a body increases and the wavelength of the radiation intensity peak shift to shorter wavelengths as the temperature increases.

Question 29

Define the Arctic Circle Latitude?

Answer 29

An altitude at 90° minus the spin axis tilt