Lecture 6 Energy Balance of Earth Flashcards
______ refers to the uninterrupted passage of shortwave and longwave energy through either the atmosphere or water.
Transmission
______ radiation experiences a change in speed and direction as a result of moving into a different medium
Refraction
______ radiation is bounced off a smooth surface in a predicable direction
Reflection
______ 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
Scattering
_______ 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.
Absorption
______ is the proportion of Kdown that is reflected or scattered from the surface and or the atmosphere.
Albedo
What is the equation for albedo?
á = (Kup/Kdown) × 100 = % value
True or False: Light coloured and smooth
surfaces have higher albedos, and dark rough surfaces have lower albedos.
True
______ is the flow of kinetic energy between molecules and from one body or substance to another resulting from a temperature difference between them.
heat
________ can be “sensed” by humans as temperature, because it comes from the kinetic energy of molecular motion.
Sensible heat
______ 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).
Latent heat
______ is the transfer of heat in electromagnetic waves, such as that from the Sun to Earth
Radiation
______ is the molecule-to-molecule transfer of heat energy as it diffuses through a substance
Conduction
Gases and liquids also transfer energy by ______, the transfer of heat by mixing or circulation.
Convection
______ is important in atmospheric and oceanic circulation, air mass movements and weather systems, internal motions deep within Earth, and movements in Earth’s crust
convection
True or False: When water evaporates from a surface, energy is stored within the evaporated water
True
Incoming energy that reaches Earth’s surface after scattering occurs is _______
Diffuse radiation
______ 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.
Scattering
True or False: Clouds reflect shortwave radiation
True
______ is the general term describing the pollution-related decline in insolation to Earth’s surface.
Global dimming
The term ______ refers to an increase in albedo caused by such clouds (stratus clouds), and the resulting cooling of Earth’s climate
Cloud albedo forcing
Cirrus clouds act as insulation, trapping longwave radiation from Earth and raising minimum temperatures. This is ______, which causes warming of Earth’s climate
cloud-greenhouse forcing
______ (condensation trails) produce high cirrus clouds stimulated by aircraft exhaust—sometimes called false cirrus clouds
Jet contrails
Explain shortwave budget
- 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
What are the key points to the longwave budget?
- 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.
This cycling of energy (longwave
radiation) between the surface and the
atmosphere is the
Greenhouse Effect.
What are the greenhouse gases?
CO2, methane, nitrous oxide, fluorinated gases
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?
No, -69 = less longwave being radiated to space = increase in temperature on earth