lecture 4 the global energy system

Question 1

absorption

Answer 1

occurs when molecules and particles in the atmosphere intercept radiation at particular wavelengths

Question 2

reflection

Answer 2

occurs when a light ray strikes a molecule or particle and bounces off again.

Question 3

scattering

Answer 3

differs from reflection in that light striking a molecule is redirected in all directions.

Question 4

Rayleigh scattering

Answer 4

Rayleigh scattering for blue wavelengths is approximately 10 times as great as for the longer red wavelengths of sunlight (the scattered blue light reaches us from all directions, and the sky appears blue).

Question 5

Mie Scattering

Answer 5

Particles (such as dust particles, water droplets etc) with diameters greater than ten times the wavelength of the solar radiation are causing non-selective scattering, also known as Mie scattering.

Question 6

The proportion of the incident light or radiation that is reflected by a surface is called

Answer 6

albedo

Question 7

counter-radiation.

Answer 7

Counter-Radiation and the Greenhouse Effect
Although the atmosphere is cooler than the surface of the Earth, it too emits long-wave radiation.
It emits this radiation in all directions, some upward to space, and some toward the Earth’s surface.
Since this downward flow is the opposite direction to long-wave radiation leaving the surface, it is termed counter-radiation.

Question 8

greenhouse effect.

Answer 8

Much of the long-wave radiation emitted upward by the Earth’s surface is absorbed by water vapour and carbon dioxide.
The absorbed energy eventually raises the temperature of the atmosphere, resulting it to emit more counter-radiation.
The mechanism, in which the atmosphere traps long-wave radiation and returns some of it to the surface, is termed the greenhouse effect.

Question 9

Average incoming energy flow, measured in watts per square metre over the course of a 24-hour day, is referred to as daily

Answer 9

insolation (incoming solar radiation).

Question 10

The seasonal pattern of daily insolation can be used as a basis for dividing the globe into broad latitude zones:

Answer 10

Equatorial zone
Tropical zones Subtropical zones Midlatitude zones

Subarctic and Subantarctic zones

Question 11

Sensible heat

Answer 11

is heat energy held by an object or substance that can be measured by a thermometer.
The store of sensible heat is proportional to the temperature of the object rises.

Question 12

Latent heat

Answer 12

is heat that is taken up and stored in the form of molecular motion.
It is associated with a change of state of substance from a solid to a liquid, from a liquid to a gas, or from a solid directly to a gas.
For example, energy is used to convert liquid water to water vapour and released when water vapour converts back to liquid water.

Question 13

Latent heat transfer occurs when

Answer 13

water evaporates from a moist land surface or an open water surface.
This process transfers heat from the surface to the atmosphere.

Question 14

Ultimately, the amount of energy received by the Earth–atmosphere system equals the amount of energy returned to space.
Therefore, on a global scale, there is a

Answer 14

radiation balance

Question 15

A full accounting of all the energy flows among the sun, the atmosphere, the Earth’s surface, and space forms the

Answer 15

global energy balance

Question 16

net radiation

Answer 16

the difference between all incoming radiation and all outgoing radiation