Lecture 6 Energy Balance of Earth

Question 1

______ refers to the uninterrupted passage of shortwave and longwave energy through either the atmosphere or water.

Answer 1

Transmission

Question 2

______ radiation experiences a change in speed and direction as a result of moving into a different medium

Answer 2

Refraction

Question 3

______ radiation is bounced off a smooth surface in a predicable direction

Answer 3

Reflection

Question 4

______ radiation is dispersed in many different directions by rough reflectors. The reflectors are aerosols, water and ice suspended in the atmosphere, and atmospheric gases. This produces diffuse solar radiation, which is the downward component of scattered insolation

Answer 4

Scattering

Question 5

_______ radiation is taken in or assimilated by the medium. This energy is then converted to
other forms of energy, such as thermal infra-red radiation and heat.

Answer 5

Absorption

Question 6

______ is the proportion of Kdown that is reflected or scattered from the surface and or the atmosphere.

Answer 6

Albedo

Question 7

What is the equation for albedo?

Answer 7

á = (Kup/Kdown) × 100 = % value

Question 8

True or False: Light coloured and smooth

surfaces have higher albedos, and dark rough surfaces have lower albedos.

Answer 8

True

Question 9

______ is the flow of kinetic energy between molecules and from one body or substance to another resulting from a temperature difference between them.

Answer 9

heat

Question 10

________ can be “sensed” by humans as temperature, because it comes from the kinetic energy of molecular motion.

Answer 10

Sensible heat

Question 11

______ is the energy gained or lost when a substance changes from one state to another, such as from water vapour to liquid water (gas to liquid) or from water to ice (liquid to solid).

Answer 11

Latent heat

Question 12

______ is the transfer of heat in electromagnetic waves, such as that from the Sun to Earth

Answer 12

Radiation

Question 13

______ is the molecule-to-molecule transfer of heat energy as it diffuses through a substance

Answer 13

Conduction

Question 14

Gases and liquids also transfer energy by ______, the transfer of heat by mixing or circulation.

Answer 14

Convection

Question 15

______ is important in atmospheric and oceanic circulation, air mass movements and weather systems, internal motions deep within Earth, and movements in Earth’s crust

Answer 15

convection

Question 16

True or False: When water evaporates from a surface, energy is stored within the evaporated water

Answer 16

True

Question 17

Incoming energy that reaches Earth’s surface after scattering occurs is _______

Answer 17

Diffuse radiation

Question 18

______ is the name for this phenomenon, which accounts for a percentage of the insolation that does not reach Earth’s surface but is instead reflected back to space.

Answer 18

Scattering

Question 19

True or False: Clouds reflect shortwave radiation

Answer 19

True

Question 20

______ is the general term describing the pollution-related decline in insolation to Earth’s surface.

Answer 20

Global dimming

Question 21

The term ______ refers to an increase in albedo caused by such clouds (stratus clouds), and the resulting cooling of Earth’s climate

Answer 21

Cloud albedo forcing

Question 22

Cirrus clouds act as insulation, trapping longwave radiation from Earth and raising minimum temperatures. This is ______, which causes warming of Earth’s climate

Answer 22

cloud-greenhouse forcing

Question 23

______ (condensation trails) produce high cirrus clouds stimulated by aircraft exhaust—sometimes called false cirrus clouds

Answer 23

Jet contrails

Question 24

Explain shortwave budget

Answer 24

• 24% of Kdown is absorbed in atmosphere by gases, aerosols and clouds
• 45% of Kdown reaches the surface as direct or diffuse radiation and is absorbed
• 31% is reflected or scattered back to space (albedo of Earth-Atmosphere)
  Thus, 69% of K9is absorbed in the system

Question 25

What are the key points to the longwave budget?

Answer 25

- shortwave radiation is absorbed at the surface and that energy is transferred to the atmosphere as latent heat (through evaporation), sensible heat (through convection and conduction) and longwave radiation (L8) - the atmosphere also absorbs K9 and that energy is also converted to latent heat, sensible heat and longwave radiation (L8and L9) - overall, the energy of outgoing longwave radiation (L8) from the surface and atmosphere to space must equal the 69% of K9 absorbed - the atmosphere absorbs longwave radiation emitted from the surface, this energy is converted to other forms of kinetic and potential energy. - in turn, the atmosphere emits longwave radiation with much of that radiation directed towards the surface (L9). - this incoming longwave energy is then absorbed at the surface and converted to other forms of energy. - the surface then transfers more sensible and latent heat to the atmosphere and emits more longwave radiation back to the atmosphere as L8 - in the atmosphere, the same processes that are described above are repeated.

Question 26

This cycling of energy (longwave radiation) between the surface and the atmosphere is the

Answer 26

Greenhouse Effect.

Question 27

What are the greenhouse gases?

Answer 27

CO2, methane, nitrous oxide, fluorinated gases

Question 28

Is the Earth-Atmosphere system actually in energy balance (i.e. is the incoming shortwave energy that is absorbed balanced by the outgoing longwave energy?

Answer 28

No, -69 = less longwave being radiated to space = increase in temperature on earth