Unit 3 Section 1 Flashcards
What is the graph called that describes the intensity of different wave lengths of radiation?
Emissions Spectra
What type of radiation does the sun emit?
Short-wave radiation
What is the peak wave length emission for the sun?
.5 microns
What is the peak wave length emission for the earth?
10 microns
What the most important factor to how much radiation a body emits?
Temperature
How do we refer to a perfect emitter of radiation?
Blackbody
How do we refer to an imperfect emitter of radiation?
Graybody
What does the Stefan-Boltzman law refer to?
The intensity of radiation based upon how the temperature raised to the fourth power
What is emissivity?
A way to describe how much radiation something can emit in relation to the maximum or a blackbody
What is the Stefan-Boltman equation for graybodies?
I = εσT4 [W m-2]
What is Wien’s law?
The wavelength of peak emission for any given body
Whats the threshold for shortwave and longwave radiation
4 microns
Warmer bodies tend to emit what type of radiation?
Shortwave radiation
What are the 3 energy transfer mechanisms?
Conduction, Convection and Radiation
What is conduction?
The transfer of energy through direct contact of molecules
What is convection?
The transfer of energy through the mixing of fluids or gasses?
What is radiation?
The transfer of energy requiring no physical medium?
What is the solar constant?
The amount of radiation the gets to earth from the sun calculated by the depletion of radiation in relation to distance squared
What is the degree by which the earth’s tilt is offset by?
23.5 degrees
What is the unit for energy flux
Watt / Meter ^ 2
What are the 3 atmospheric influences on insolation?
Absorption, Scattering, Transmission
What is insolation?
The amount of solar energy received by something
What is albedo?
The percentage of energy reflected by an object?
What is reflection?
Energy being redirected and dispersed without being absorbed
What is specular reflection?
A reflection of energy as an intense beam like a mirror
What is scattering?
Energy deflected as dispersed energy into less intense beams
What is diffuse radiation?
When gases in the atmosphere scatter radiation back into space and toward the surface
What is direct radiation?
Radiation that goes directly to the surface and is different in intensity than scattered radiation
What is diffuse reflection?
A reflection that redirect’s light in all directions
What is Rayleigh Scattering?
Scattering of radiation by agents that are 1/10 the size of the wavelength
(Forward and backward scattering)
What is Mie Scattering?
Scattering of radiation by agents that are the same size of the wavelength
(Forward scattering)
What is Non-Selective Scattering?
Scattering of radiation equally by agents that are larger than the wavelengths, particularly clouds
What is Transmission?
The amount of radiation that passes through the atmosphere and directly hits the earths surface. I.E. Energy that isn’t influenced
What are the factors of how much solar radiation reaches the surface?
Amount of energy coming from the sun at a given point. I.E. Seasons and time of day and location on Earth
Amount of energy influenced such as scattering, reflection and absorption
Why doesn’t the Earth permanently heat up from all the energy it intakes?
The Earth energy balance means that the Earth also gives off radiation in the form of shortwave radiation
Where does the longwave radiation the Earth emits go?
It is largely absorbed by the atmosphere
What are the primary absorbers of longwave radiation in the atmosphere?
Water vapor and CO2
What is the atmospheric window?
The range of wavelengths not absorbed by the atmosphere
What is the exception to the atmospheric window?
Clouds, they absorb all longwave radiation including that within the atmospheric window
What is the laminar boundary layer?
It is the thin temperature gradient above a surface that is warming a gas or liquid
What are the 2 different types of convection?
Free convection, Forced convection
What is free convection?
Mixing related to buoyancy
What is forced convection?
Convection initiated by eddies and other disruptions to smooth, uniform flow
What are the two types of energy convection transfers?
Sensible heat, Latent Heat
What is sensible heat?
Energy/heat that we feel and SENSE
What is latent heat?
Energy/heat required to change phases
What is the greenhouse effect?
The process by which the atmosphere and the clouds let in shortwave solar radiation but trap in longwave Earth radiation which is then re-radiated back to the clouds and that process repeats.
What is inside of a maximum thermometer?
Mercury
What is inside of a minimum thermometer?
Alcohol
What is wiens law equation?
λ max = b (constant of proportionality) / t (absolute temperature)
What is the planetary albedo?
30%
What is Wind Chill Temperature?
It indicates how cold a particular temperature feels given a certain wind speed
What is Heat index?
it indicates how hot a partcicular temperature feels given a certain atmospheric moisture content
What is MRT?
Mean Radiant Temperatures indicates the comfort level when radiative considerations are accounted for.
What is Wet-bulb Globe Temperature?
Combines the heat index and MRT
What is the daily mean?
Average of maximum and minimum temperatures for the day
What is the daily temperature range?
It is obtained by subtracting the minimum temperature from the maximum temperature
What is the monthly mean?
The sum of all daily means/number of days.
What is the annual mean?
The sum of all monthly means/number of months
