49 terms

Meteorology Chptr 2

Distinguish between temperature and heat.
Tempter is the quantity that tells us how warm or cold an object is. Heat is energy that flows from a higher-temperature object to a lower-temperature object.
How does the average speed of air molecules relate to the air temperature?
Higher temperatures correspond to faster average speeds
Explain how heat is transferred in our atmosphere by:(a)conduction(b)convection(c)radiation
A.} By molecular activity from one substance to another.Transfer is always from warmer to colder reegions.
B.} Tranesfer of heat by the mass movement of a fluid (water or air)
c.} Energy form the sun travels through space and the atmosphere in the form of a wave (electromagnetic waves)
What is latent heat? How is latent heat an important source of atmospheric energy?
A.} latent heat is the energy involved in the change of state.
B.} latent heat released from the billions of vapor droplets during codensation and cloud formation fuels storm energy needs, warms the air, and encourages taller cloud growth.
How does the Kelvin temperature scale differ from the Celsius scale?
Kalvin Scale begins at absolute zero(273) and contains no negative numbers.
Celsius Scale begins at absolute zero (Number 0 is on the scale) and it contains negative numbers for freezing points.
How does the amount of radiation emitted by the earth differ from that emitted by the sun?
The earth emits most of its radiation at a longer wavellenghts between about 5 and 25 um, while the sun emits the majority of its radiation at wavelenghts less than 2um.
How does the temperature of an object influence the radiation it emits?
The higher the temperature, the faster the electrons vibrate, and the shoter are the wavelenghts of the emitted radiation.
How do the wavelengths of most of the radiation emitted by the sun differ from those emitted by the surface of the earth
The sun emits a maximum amount of radiation at wavelenghts near 0.5 um.
Cooler earth with an average surface temperature of 288 k (rounded to 300k), emits maximum radiation near wavelenghts of 10 um
When a body reaches a radiative equilibrium temperature, what is taking place
At this temperature, the earth (behaving as a black body) is absorbing solar radiation and emitting infrared radiation at equal rates, and it average temperature does not change.
Why are carbon dioxide and water vapor called selective absorbers
Water vapor and carbon dioxide are strong absorbers of infrared radiation and poor absobers of visable solar radiation
Explain how the earth's atmospheric greenhouse effect works
They allow most of the sun's visible radiation to reach the surface, but they absorb a good portion off the earth's outgoing infrared radiation , preventing it from escaping into space.
What gases appear to be responsible for the enhancement of the earth's greenhouse effect
Carbon dixoide (C02), Methane (CH4), Nitrous oxide (N2o), and Cholrofluorocarbons (CFCs)
Why does the albedo of the earth and its atmosphere average about 30 percent
Average for an entire year, the earth and itsatmospher (including its clouds) will redirect about 30% of the sun's incoming radiation back to space, which gives the earth and its atmosphere a combined albedo of 30%.
Explain how the atmosphere near the earth's surface is warmed from below
Solar radiation heats the atmosphere from below by soil conduction and gas convection
In the Northern Hemisphere, why are summers warmer than winters even though the earth is actually closer to the sun in January
In the winter the Earth is closer to the Sun. So the sun's reflection is spread out to cover more area. In summer the Earth is further away from the sun. The sun's reflection will focus on a smaller area.
What are the main factors that determine seasonal temperature variations
The seasons are caused by the earth being tilted on its axis as it revolves around the sun. The tilt causes annual variations in the amount of sun light that strikes the surface as well as variations in the length of time the sun shines at each latitude.
If it is winter and January in New York City, what is theseason and month in Sydney, Australia
It is summer, because it is in the opposite side of the world from New York. The Earth can be arbitrarily divided into 2 parts, the Northern and Southern Hemisphere, where the season in one hemisphere is the opposite of that in the other. Australia is in the Southern Hemisphere, and New York in the Northern Hemisphere.
During the Northern Hemisphere's summer, the daylighthours in northern latitudes are longer than in middle latitudes. Explain why northern latitudes are not warmer
Due to the axial tilt of the planet, the sun is at a lower angle in the northern latitudes. The angle means that the radiation from the sun has to travel through more atmosphere to get to the surface, thus more is absorbed, reflected, or scattered by the atmosphere, thus colder temperatures.
Explain why the vegetation on the north-facing side of a hill is frequently different from the vegetation on thesouth-facing side of the same hill
South side of hill gets more sunlight at middle latitudes, greater evaporation, drier soil. South and North sides get different amounts due to angle.
What is solar wind?
A continuous stream of high-energy particles is released into space at all directions from the suns corona. Solar flares can increase the speed and strength of the solar wind. This increase in the solar wind can interfere with radio signals and telephone communications on Earth.
Explain how the aurora is produced?
The aurora is produced by the solar wind disturbing in magnetosphere.
What is Stefan Boltzmannn law?
Stefan's law, states that the total energy radiated per unit surface area of a black body per unit time (also known as the black-body irradiance or emissive power), is directly proportional to the fourth power of the black body's thermodynamic temperature
What is Wilhelm Wien's law?
states that the wavelength distribution of thermal radiation from a black body at any temperature has essentially the same shape as the distribution at any other temperature, except that each wavelength is displaced on the graph.
What is Kirchoff's law?
The current entering a junction point is equal to the current leaving.
Objects that selectively absorb radiation also selectively emit radiation at the same wavelength.
Why is the Kelvin scale often used in scientific calculations?
It contains no negative numbers.
Based on your experience, would a temperature of 250 K be considered warm or cold?
Kalvin Scale begins at absolute zero(273) and contains no negative numbers.
In the atmosphere, how does advection differ from convection?
Convection is heat transfer by the mass movement of a fluid in the vertical (up/down) direction. This type of heat transfer takes place in liquids and gases. This occurs naturally in our atmosphere.
Advection is the transfer of heat in the horizontal (north/east/south/west) direction. In meteorology, the wind transports heat by advection. This happens all the time on Earth, heat is transported in many ways.
Which photon carries the most energ---infrared, visible, or ultraviolet?
Ultraviolet radiation
If the earth's surface continually radiates energy, why doesn't it become colder and colder?
The earth absorbs solar heat,,,,,
why do most climate models predict that the earth's average surface temperature will increase by an additional 3.0 celcusis (5.4*F) by the end of this century?
That the continuing increase of CO2 and other greenhouse gases.
Northern Hemisphere, We call this light show?
Aurora Boealis
Southern Hemisphere, we call this light show?
Aurora Australis
The ability to do work
Potential energy
Potential for work mass x gravity x height
Kinetic energy
Energy of a moving object (half of mass x velocity squared)
Average speed of atoms and molecules
Energy in the process of being transferred from one object to another because of a difference in temperature.
First law of thermodynamic
Energy cannot be destroyed or created
Heat capacity
The heat energy absorbed to raise a substance to a given temperature
Specific heat
The heat capacity divided by mass or the amount of energy required to raise one gram of a substance 1 c
Latent heat
Energy involved in the change of state.
Ice to vapor
Absorb energy, cool environment ( melt, evaporation, sublimation)
Vapor to ice
Release energy, heat environment ( freeze, condense, deposition)
Occurs as warmer molecules transmit vibration, and hence heat, to adjacent cooler molecules.
Heat energy moving as fluid from hotter to cooler areas.
Convection circulation
Warm air expands and rises then cools and sinks; thermal cell
Energy from sun travels through space and atmosphere in the form of wave ( electromagnetic waves)
Horizontally moving part of circulation (wind).
Wien's law
The hot sun radiates at shorter wavelengths that carry more energy, and the fraction absorbed by the cooler earth is then re-radiated at a longer wavelength.