Chapter 2 Flashcards
Force
the mass of the body multiplied by the acceleration the force causes in the body
Acceleration
a change in speed or a change in direction of an object’s movement
Work
The amount of work done on your book is the distance travled times the force in the direction of that displacement
Energy
The capacity to do work
Kinetic energy
The work that a body can do by virtue of its motion
Potential energy
The work an object can do as a result of its relative position
Parcel of air
A hypothetical balloon-like bubble of air, fleible but impermeable, and perhaps as large as a parking lot
Temperature
a measure of the average kinetic energy of a substance
Kelvin scale
An absolute scale in which zero is the lowest possible temperature
Calorie
The unit used to measure amounts of energy
the energy needed to raise the temperature of 1 gram of water 1 degree Celsisus
Joule
another unit used to measure amounts of energy
0.2389 calories
Power
The rate at which energy is transferred, received, or released
Watt (W)
a unit of power that represents the transfer of 1 Joule of energy per second
Heat
The energy produced by the random motions of molecules and atoms
The total kinetic energy of a sample of a substance
Specific heat
The amount of energy required to increase the temperature of 1 gram of that substance 1 degree celsius
Conduction
The process of heat transfer from molecule to molecule
requires contact
ex. when we touch an object to see if it’s warm or cold
Thermal conductivity
The amount of energy transferred by conduction depends on the temperature difference bewteen the two objects and their thermal conductivity
- the ability of a substance to conduct heat by molecular motions is defined by its thermal conductivity
Convection
The process of transferring energy vertically
free convection - when an air parcel is heated and becomes less dense than the air around it and therefore rises
Temperature advection
The horizontal transport of energy in the atmosphere
warm advection - when the warm air replaces cooler air
Latent heat
The heat absorbed or relased per unit mass when water changes phase
Latent heat of melting
The amount of energy absorbed by water to change 1 gram of ice into liquid water, and it is equal to 80 cal for each gram of ice
Latent heat of fusion
The amount of energy relased into the environment when water freezes
Vaporization or evaporation
The transition of water from the liquid phase to the gas phase
Latent heat of vaporization
The amount of heat required to evaporate 1 gram of liquid water
Latent heat of condensation
The amount of energy released when water vapor condenses to a liquid form
Depoisition
Water vapor may change directly into ice in this process
Sublimation
Ice may also directly enter the gas phase without melting
Latent heat of sublimnation =
latent heat of deposition
Evaporation is a ________ process that removes energy from the physical environment
cooling
Condensation is a __________ process that supplies energy to the enviornment
heating
Solar radiation is one form of ______________
radiant energy, or energy in the form of waves that are not composed of matter
Radiant energy is also called ___________
radiation and electromagnetic energy
Wavelength
The distance between wave crests
Amplitude
half of the height from the peak of the crest to the lowest point of the wave
Waves are characterized by two properties:
wavelength and amplitude
Solar radiation is sometimes referred to as _____________
shortwave radiation
Solar energy includes UV, visible, and near-infarred radiation
Ultraviolet (UV) light
where wavelengths range from 0.2um to 0.4 um
Longwave radiation (terrrestrial radiation)
emitted by the Earth is less energetic than solar radiation and is characterized by much longer wavelengths, primarily between 4 um and 100 um
All objects with a temperature above __________ emit radiation
absolute zero
Emissivity
A measure of an object’s ability to emit radiation
Materials are assigned an emissivity value betwen 0 - 1.0
Blackbody
Has an emissivity of 1 and is an object that absorbs all the electromagnetic energy that falls on the object, no matter what the wavelegth of the radiation
Stefan-Boltzmann Law
The amount of radiative energy that is emitted by an object (watts per square meter) is related to the fourth power of its Kelvin temperature
As an object warms, it emits more ____________
radiation
Wien’s law
The wavelength or radiant energy emitted depends on the temperature of the emitting body
Wavelength (in microns) of maximum radiation emitted by an object = 2900 / Object’s temperature in Kelvin
Wien’s law can be summarized as follows:
The hotter the object, the shorter the wavelength of maximum emission of radiation
When radiation interacts with an object, it can be:
- Absorbed - increases the energy of the molecule,
- Reflected - energy reflected by an object is sent back. mirrors are good reflectors and clouds
- Transmitted - passes through the object, although it may change direction
Albedo
Describes the percentage of light that it reflects
The higher the albedo - the brighter the object
Key determiner of the temperature of the planets in the solar system
How much radiation energy the atmosphere or an object absorbs depends on the following:
- The radiative properties of the mutual
- The amount of time the object is exposed to the emitted energy
- The amount of material
- How close the object is to the source of energy
- The angle at which the radiation is striking the object
Blackbody
An object that absorbs all the electromagnetic energy that falls on the object, no matter what the wavelength of the radiation
Kirchhoff’s law
A good absorber of radiation is also a good emitter of radiation at that same wavelength
The earth is furthest from the sun on approximately _____
July 4th (aphelion)
Earth is closest to the Sun on approximately __________
January 4th (periphelion)
_____________ causes the seasons
The earth’s tilt
The tilt is referred to as the _________________
angle of inclination
The equinoxes occur when _____________________
The sun’s rays strike the equator at noon at an angle of 90 degrees.
March 20, September 22 or 23
The variation of solar energy at the surface by latitude is caused by the following:
- Changes in the angle that the Sun’s rays hit the Earth
- The number of daylight hours
- The amount of atmosphere the SUn’s rays have to pass through
The angle at which the SUn’s energy strikes a particular location on Earth is called the ____________
solar zenith angle
The average amount of solar energy that reaches the outer limits of our atmosphere on a surface that is perpendicular to the solar rays is referred to as the ________________
solar constant
The length of day and solar zenith angle are both determined by ____________________
the tilt of the Earth’s axis
A larger solar zenith angle causes the Sun’s energy to pass ________________
through more atmosphere
Of the atmospheric gases, ____________ absorbs most of the shortwave radiation
ozone
Infared atmospheric window
10 um - 12 um region
The atmosphere is relatively transparent to infared radiation emited by the surface t these wavelengths
Atmospheric window
Exists around 4 um
Clouds are good:
reflects of solar energy
They are good emitters and absorbers of longwave energy
Greenhouse effect
The selective nature of radiation absorption by atmospheric gases is the fundamental cause of the greenhouse effect
________________ and ____________________ are the terms used to explain the relationship between the observed rise in global temperature and the absorbed increas in atmospheric carbon dioxide
Greenhouse warming
and
Enhanced greenhouse effect
The more carbon dioxide there is, the more =>
infarred energy is absorbed
Greenhouse gases
Gases that ar transparent to solar energy while absorbing terrestrial energy will warm the atmosphere because they allow solar energy to reach the surface and inhibit longwave radiation from reaching outer space
Important greenhouse gases
Water vapor
Ozone
Methane
Nitrous oxide
And CFS
______________ is the most important greenhouse gase because of its relative abundance and its ability to absorbe a lot of longwave energy in many different wavelengths
Water vapor
*a warmer atmosphere can mean more water vapor in the atmosphere and possibly more clouds
Sensible heating
Represents the combined processes of conduction and convection and amounts to a total of 24w/m^2 transferred from the surface to the atmosphere
Radiative forcing
The change in the net radiation at the tropopause
What causes seasons?
The Earth’s tilt, combined with its orbit around the sun
The energy emitted to space has wavelengths of _________
4 to 100 microns
Much of the energy that escapes from the Earth to space is in the narrow band of 10 um to 12 um, called the ________________
infared atmospheric window
