Atmosphere 1- Insolation & Earths Energy Balance - Sarah Greene Flashcards
What is a system?
a portion of the universe separated from another part of the universe to monitor change
What are 2 examples of systems? (general)
the earth
a beaker of water
a flock of birds
What is an isolated system?
no energy or matter exchanged with the outside
What are the three types of system? (earth systems)
Isolated
Closed
Open
what is a closed system?
Energy exchanged but not matter
What is an open system?
Energy and matter exchanged
What are all the parts of the climate system?
Atmosphere
Cryosphere
Biosphere
Lithosphere
Hydrosphere
Anthroposphere
What is energy?
The capacity to do work
What are some of the energy sources for earths surface?
Accretionary heat
Radioactive heat
Tidal heating
Core formation
Solar energy
What is Accretionary heat?
energy left from earths formation
What is radioactive energy?
Energy released from radioactive decay
What is tidal heating?
Frictional heating caused by distortion
How does earths surface get energy from core formation?
crystallisation releases latent heat
Where does the vast amount of earths surface energy come from?
from our closest star- the sun
How much of earths surface energy come from the sun? (%)
99.99%
What drives energy from the sun?
nuclear fusion
What is the basis on insolation by spatial patterns?
distribution of solar rays is affected by latitude
What will solar intensity be like at 45*?
acute angle so less intense oblique rays
What will temperature be like with less intense solar rays?
cooler
What will solar intensity be like at 90*?
more solar intensity
What will temperature be like with more intense solar rays?
warmer
What are the equinoxes in orbit temporal patterns?
the earth receives different amounts of energy based on tilt and closeness to the sun
How much does does the radiation at the top of the earths axes vary? (%)
3.5%
What creates an energy balance?
incoming energy degraded into longer wavelength radiation re-radiated to outer space this balances with incoming solar
How many terawatts of energy flow does earth receive?
greater than 174,000
What is insolation?
solar energy reaching earths surface per unit area (Watt/m*2)
What is earths solar constant? (W/m*2)
1368 W/m*2
What is albedo?
proportion of incoming radiation that is reflected unchanged
What will a high albedo surface be like?
highly reflective
What factors can affect albedo?
clouds
land surface
What is re-radiation?
proportion solar energy not reflected but is absorbed into earth system by materials in atmosphere and land surface
What can transfer energy around the earth system?
weather
wind
waves
plant growth
What eventually happens to energy transferred around the earth system?
eventually turns to heat which is re-radiated
What is blackbody?
an ideal theoretical object where both emits and absorbed radiation perfectly at all wavelengths
What is the Stefan Boltzmann law?
energy radiated by black body proportional to fourth power of its absolute temperature
What is earths albedo when calculating if earth is a blackbody?
0.3
Based on the blackbody equation what would earths temp be?
-23*C
Why do we know the earth blackbody equation isnt the case?
earth would be frozen if at -23*C
How would you describe earths atmosphere?
dynamic but roughly stable
What would happen is outflow imbalance compared to inflow?
temperature would be infinite growth and vice versa 0K (kelvin)
What is power emitted by radiation sensitive to?
temperature
How does increased temperature affect infrared emissions?
significantly increased
What happens when temperature reaches a certain level with inflow and outflow of energy?
will reach a point of balance where emission into space balances solar energy inflow
What happens if there is any change of in for outflows in energy from the earth system?
will usually return earth to a new steady state at different temperature average
What is the amount of energy input from the sun like on a short timescale? (only a few years)
steady relatively stable
What is the variation like in energy input from the sun like on a short timescale? (%)
0.5% so almost constant
What affects the amount of energy input from the sun on a medium timescale? (millennia)
changes in orbit
What can change amount of energy input from the sun on a long timescale? (billions of years)
sun steadily brightens
What was the suns emissions like when it was a very young star?
4.6 billion years ago emitted 70% of present energy
What can soot and aerosol particles from volcanoes do to radiation?
cause it to be scattered and or absorbed
what are some examples of different land surfaces affecting albedo?
ice cover - light white surface high albedo
ocean/ land- darker low albedo more absorbed
Are GHG natural or artificial?
Both
What naturally happens when solar energy reaches earth?
1/3 scattered
rest absorbed
What forms does solar energy reach earth?
UV
visible light
What type of energy does earth emit to space?
infrared
What happens to some of the infrared emitted by earth? (Natural GHG effect)
some is absorbed by GHG in the atmosphere
What is the benefit of the natural GHG effect absorbing some of the emitted infrared?
reason earth average temp is 14c instead of -23c (earth blackbody equation)
How can graphs show earth is not a blackbody?
there would be smooth curves on the graph but earth graph has variation between surface and atmosphere (for energy levels)
How much more GHG are in the atmosphere as a result of human actions? (%)
43%
Who discovered the GHG effect?
Euness foot was first to do work on GHG effect unknown how many others relied upon on works
