On National Teacher Day, meet the 2024-25 Kenan Fellows
Heating of The atmosphere
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6. ATMOSPHERE
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From the word ‘atmo’ which means gas or vapor
The layer of gases surrounding the earth
Makes life possible on earth
Gives man air, water, heat, and protects him
against harmful rays of the sun and against
meteorites
• Consists of 78 percent nitrogen, 21 percent
oxygen, 0.93 percent argon , 0.03 percent carbon
dioxide and 0.04 percent of other gases.
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8. +
Mechanisms of Heat Transfer
• Conduction:
– Conduction is the heat transferred through molecular
and electron collisions from one molecule to another.
– Metals are good conductors
• Convection:
– Convection is the heat transferred via movement or
circulation of a substance, primarily vertically
– Warm air rising creates thermal currents.
– Advection describes the primarily horizontal
component of convective flow.
10. +
Mechanisms of Heat Transfer
• Solar radiation travels through space providing light
and heat energy.
– Wavelength describes the length of the crest of one
radio wave to the next.
– Visible light, often referred to as “white light,” actually
describes the sensitivity of the human eye to a range of
wavelengths.
– Infrared radiation cannot be seen by the human eye, but
is detected as heat.
– Ultraviolet radiation, on the opposite side of the visible
range, consists of wavelengths that may cause sunburns.
11. +
Mechanisms of Heat Transfer
• Laws of radiation:
1. All objects continually emit radiate energy of a
range of wavelengths.
2. Hotter objects radiate more total energy per unit
than colder ones.
3. Hotter objects radiate more short wave radiation
than cooler ones.
4. Objects that are good absorbers of radiation are
also good emitters.
12. +
What Happens to Incoming
Solar Radiation?
• Reflection:
– Light bounces back from an object at the same angle
and intensity.
• Scattering:
– Scattering produces a large number of weaker rays
traveling in different directions.
• Backscattering:
– Scattering, both backwards and forwards, is known as
backscattering.
13. +
What Happens to Incoming
Solar Radiation?
• Reflection and the Earth’s albedo:
– Albedo is the % of radiation reflected by an object.
• The albedo for Earth is about 30%.
• For the moon, the albedo is about 7%.
• Light objects have higher albedos and darker objects
have lower albedos.
16. +
What Happens to Incoming
Solar Radiation?
• Diffused light:
– Diffused light is the result of dust particles and gas
molecules scatter light in different directions.
– This diffusion results in clear days with a bright
blue sky.
– A red sun on the horizon is the result of the great
distance solar radiation must travel before it
reaches your eyes.
17. +
The Role of Gases in the Atmosphere
• Heating of the atmosphere
– When gas molecules absorb radiation, this energy
is transformed into internal molecular motion,
detected as a rise in temperature
19. +
The Role of Gases in the Atmosphere
• The greenhouse effect:
– The greenhouse effect is a natural phenomenon
and is a result of the Earth’s atmosphere trapping
some outgoing radiation.
– Carbon dioxide and water vapor absorb longwave
radiation, which heats the air.
– The greenhouse effect is NOT the same as global
warming.
20. +
Earth’s Heat Budget
• Annual energy balance:
– Incoming and outgoing radiation account for the
Earth’s heat budget.
– Figure 2-23 on page 56 (on next slide)
22. +
Earth’s Heat Budget
• Latitudinal heat balance:
• Balance of incoming and outgoing radiation
applicable for whole earth is not maintained on
latitudes.
– At 38°, incoming radiation and outgoing radiation are
equal.
– Above 38°, the atmosphere loses more radiation.
– Below 38°, the atmosphere gains more radiation.
• This energy imbalance is what drives winds and
ocean currents.
23. +
Mechanisms of Heat Transfer
• Conduction:
– Conduction is the heat transferred through molecular
and electron collisions from one molecule to another.
– Metals are good conductors
• Convection:
– Convection is the heat transferred via movement or
circulation of a substance, primarily vertically
– Warm air rising creates thermal currents.
– Advection describes the primarily horizontal
component of convective flow.
25. +
Mechanisms of Heat Transfer
• Solar radiation travels through space providing light
and heat energy.
– Wavelength describes the length of the crest of one
radio wave to the next.
– Visible light, often referred to as “white light,” actually
describes the sensitivity of the human eye to a range of
wavelengths.
– Infrared radiation cannot be seen by the human eye, but
is detected as heat.
– Ultraviolet radiation, on the opposite side of the visible
range, consists of wavelengths that may cause sunburns.
26. +
Mechanisms of Heat Transfer
• Laws of radiation:
1. All objects continually emit radiate energy of a
range of wavelengths.
2. Hotter objects radiate more total energy per unit
than colder ones.
3. Hotter objects radiate more short wave radiation
than cooler ones.
4. Objects that are good absorbers of radiation are
also good emitters.
27. +
What Happens to Incoming
Solar Radiation?
• Reflection:
– Light bounces back from an object at the same angle
and intensity.
• Scattering:
– Scattering produces a large number of weaker rays
traveling in different directions.
• Backscattering:
– Scattering, both backwards and forwards, is known as
backscattering.
28. +
What Happens to Incoming
Solar Radiation?
• Reflection and the Earth’s albedo:
– Albedo is the % of radiation reflected by an object.
• The albedo for Earth is about 30%.
• For the moon, the albedo is about 7%.
• Light objects have higher albedos and darker objects
have lower albedos.
31. +
What Happens to Incoming
Solar Radiation?
• Diffused light:
– Diffused light is the result of dust particles and gas
molecules scatter light in different directions.
– This diffusion results in clear days with a bright
blue sky.
– A red sun on the horizon is the result of the great
distance solar radiation must travel before it
reaches your eyes.
32. +
The Role of Gases in the Atmosphere
• Heating of the atmosphere
– When gas molecules absorb radiation, this energy
is transformed into internal molecular
motion, detected as a rise in temperature
34. +
Earth-Sun Relationships
• Earth’s two principal motions:
– Rotation is the spinning of the earth on its axis,
resulting in the daily cycle of day and night.
– Revolution is the movement of the Earth in an
elliptical orbit around sun, producing one year.
• Its perihelion, the closest point to sun occurs on about
January 3.
• The aphelion, which is the furthest point from sun
occurs on about July 4.
37. +
Earth-Sun Relationships
• What causes the seasons?
– The gradual change in day length accounts for
some of the differences in the seasons.
– A change in angle of the sun (altitude) also plays a
significant role.
38. +
Earth-Sun Relationship
• When the sun is directly overhead (at 90°) the
solar rays are more concentrated and more
intense
• The angle of the sun determines the path solar
rays take as they pass through the atmosphere
– At 90° rays travel the shortest path to the surface
– At lesser angles the rays have farther to travel and
more rays get dispersed
41. +
Earth-Sun Relationships
• Solstices:
– The summer solstice occurs on or about June 21 or 22.
• At that time, the sun’s rays are vertical on the Tropic
of Cancer. (23 ½° north latitude)
• It also produces the longest day in the northern
hemisphere.
– The winter solstice occurs on or about December 21 or
22.
• The sun’s rays are then vertical on the Tropic of
Capricorn. (23 ½° south latitude)
• This results in the shortest day in the northern
hemisphere.
42. +
Earth-Sun Relationships
• Equinoxes:
–Equinox means that day and night are equal.
– The autumnal (fall) equinox happens on or about
September 21 or 22.
– The vernal (spring) equinox occurs on or about
March 21 or 22.
• The sun’s rays are vertical on the equator. (0°)
• Earth isn’t tilted away or towards the sun
44. +
Energy, Temperature, and Heat
• Energy is the capacity to do work.
• 2 forms of energy:
– Kinetic energy describes an object in motion: the
faster the motion, the greater the energy.
– Potential energy means that an object is capable of
motion or work. Substances such as
food, gasoline, or wood contain potential energy.
45. +
Energy, Temperature, and Heat
• Temperature:
– Temperature is a measure of the average kinetic
energy of atoms or molecules in a substance.
• As temperature increases, energy is gained.
– Because the particles move faster
• As temperature decreases, energy is lost.
46. +
Energy, Temperature, and Heat
• Heat:
– Heat is the energy transferred in or out of object
due to temperature differences.
– Energy absorbed but with no increase in
temperature is called latent heat.
– Sensible heat is heat we can feel or measure with a
thermometer.
47. +
Earth-Sun Relationships
• Earth’s two principal motions:
– Rotation is the spinning of the earth on its
axis, resulting in the daily cycle of day and night.
– Revolution is the movement of the Earth in an
elliptical orbit around sun, producing one year.
• Its perihelion, the closest point to sun occurs on about
January 3.
• The aphelion, which is the furthest point from sun
occurs on about July 4.
48.
49. Troposphere
• The troposphere is the first layer above the surface and
contains half of the Earth's atmosphere. Weather occurs in
this layer.
• The troposphere begins at the Earth's surface and extends
up to 4-12 miles (6-20 km) high. This is where we live. As
the gases in this layer decrease with height, the air become
thinner. Therefore, the temperature in the troposphere also
decreases with height. As you climb higher, the
temperature drops from about 62°F (17°C) to -60°F (-51°C).
Almost all weather occurs in this region.
50. Stratosphere
• Many jet aircrafts fly in the stratosphere because
it is very stable. Also, the ozone layer absorbs
harmful rays from the Sun.
• The Stratosphere extends from the tropopause
up to 31 miles above the Earth's surface. This
layer holds 19 percent of the atmosphere's gases
and but very little water vapor.
51. Mesosphere
• Meteors or rock fragments burn up in the
mesosphere.
• The mesosphere extends from the stratopause to
about 53 miles (85 km) above the earth. The
gases, including the oxygen molecules, continue
to become thinner and thinner with height. As
such, the effect of the warming by ultraviolet
radiation also becomes less and less leading to a
decrease in temperature with height.
52. Thermosphere
• The thermosphere is a layer with auroras. It is
also where the space shuttle orbits.
• The Thermosphere extends from the
mesopause to 430 miles (690 km) above the
earth. This layer is known as the upper
atmosphere.
53. Exosphere
• The atmosphere merges into space in the extremely
thin exosphere. This is the upper limit of our
atmosphere.
• The Exosphere is the outermost layer of the
atmosphere and extends from the thermopause to
6200 miles (10,000 km) above the earth. In this
layer, atoms and molecules escape into space and
satellites orbit the earth. The transition boundary
which separates the exosphere from the thermosphere
below it is called the thermopause.
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56.
57. Weather
• A local and temporary condition in
the air or the atmosphere.
• Heat, moisture and the wind in
different combinations produce the
different atmospheric conditions
known as weather
60. Elements of Climate
1. Temperature- refers to the quantity of heat present n a
particular mass.
2. Precipitation- refers to the descent of all forms of
moisture from the atmosphere
3. Humidity- refers to the presence of water vapor in the air
4. Atmospheric Pressure- refers to the mass weight of a
column of air above a given point
5. Wind- refers to the air in horizontal motion
64. Reference List
Hansen, James R. (Jun 1987). "Chapter
Space". Engineer in Charge: A History of
the Langley Aeronautical Laboratory, 19171958. The NASA History Series. sp-4305.
United States Government Printing. 12:
Hypersonics and the Transition to
www.luc.edu/.../heating-atmosphere.pdf
www.docudesk.com
