PREVIEW
Chapter 17 ATMOSPHERE
1. The Atmosphere in balance
A. The composition of the atmosphere
B. Recycling of atmospheric materials
C. Delicate balance (the balance of our current atmosphere)
2. Heat and the atmosphere
A. How heat energy moves
B. Structure of the atmosphere
a. Troposphere
b. Stratosphere
c. Mesosphere and Thermosphere
d. Ionosphere
C. Insolation and the atmosphere
a. Heat budget of the earth and the atmosphere
3. Local temperature variations
A. Intensity and insolation
a. Time of day
b. Latitude
c. Time of year
d. Cloud cover
B. Heating of water and land
C. Temperature maps
4. Human impact on the atmosphere
A. Common air pollutants
B. Acid rain
C. Smog
D. Ozone depletion
E. Global warming
Chapter 17 – 1
THE ATMOSPHERE IN BALANCE
Objectives:
- Describe the formation of the early atmosphere and the composition of the lower atmosphere
- Demonstrate how the earth system continually recycles gasses and how certain activities disturb the atmosphere in balance
1. The composition of the atmosphere
A. Volcanic eruptions
a. Earth’s early atmosphere
B. Creation of oxygen
a. splitting of water molecules
b. photosynthesis
C. Today’s lower atmosphere
a. main gasses (table on page 366)
b. Percentages of nitrogen and oxygen
c. water vapor
d. dust particles
2. Recycling of the atmospheric materials
A. Elements and compounds moving through the geosphere, hydrosphere, and biosphere (see picture page 367)
a. balance of a product leaving the atmosphere is balanced by a product being replaced in the atmosphere over the same period of time
B. Oxygen, water, and carbon dioxide move cycle through the atmosphere
3. A Delicate Balance
A. Balance may be disturbed
Mauna Loa data
Chapter 17 – 2
HEAT AND THE ATMOSPHERE
Objectives:
- Describe how energy from the sun moves through the atmosphere by radiation, conduction, and convection
- Identify the characteristics of each atmospheric layer
- Analyze Earth’s heat budget
1. How Energy Moves
A. The sun drives all weather and is essential for almost all life on earth
B. Heat energy enters and moves through the atmosphere in three different ways:
a. RADIATION
b. CONDUCTION
c. CONVECTION
C. Discussion of boiling water graphic on page 369
2. Heat and Temperature
A. Heat and temperature are not the same but are related
a. Temperature
b. Heat
3. Structure of the Atmosphere
A. Scientists use temperature to divide the atmosphere into 4 layers: troposphere, stratosphere, mesosphere, thermosphere
B. Troposphere:
a. Lowest layer
b. Temp decreases with altitude
- conduction, convection, and radiation
c. Tropopause
d. Density of atmosphere decreases with height
e. Weather!!!!
C. Stratosphere:
a. Ends about 50 K from earth’s surface
b. Temperature increases with altitude
c. Ozone and ultraviolet light
d. Stratopause
D. Mesosphere and Thermosphere:
a. Mesosphere is third layer, found between 50 and 90 K above earth’s surface
b. Temperature drops with increasing altitude
c. Mesopause
d. Thermosphere is fourth layer of atmosphere, found above 90 K and then thins out into space
e. Temperature increases with altitude even though the atmosphere is the thinnest here
f. Thermosphere is separated into layers of different gasses, with the heavier gasses on the bottom and the lightest gasses on the top
E. The Ionosphere:
a. The ionosphere is a portion of the thermosphere between 90-500 K
b. Air is highly ionized (loss/gain of electrons on atoms)
c. Affected by solar events
- sunspots
- Auroras
4. Insolation and the Atmosphere
A. In the atmosphere, energy is always flowing
B. Insolation
a. Discussion of picture on page 373 (global heat budget)
C. Global Heat Budget represents the overall flow of energy into and out of the atmosphere
D. Global Heat Budget in balance???
E. Heat Budget of Earth and the Atmosphere
a. % of insolation absorbed by atmosphere
b. radiation, conduction, evaporation, and condensation
c. energy transfer from earth’s surface
d. greenhouse effect
Chapter 17 – 3 LOCAL TEMPERATURE VARIATIONS
Objectives:
- Identify the factors that cause the intensity of insolation to vary from place to place
- Describe how the characteristics of a material affect it’s rate of solar absorption
- Analyze a temperature map
1. Intensity of Insolation
A. Intensity of insolation varies
a. time of day
- intensity of insolation greatest at noon
- hottest time of day after noon, coolest time of day is just before sunrise
b. time of year
- year’s hottest temperatures occur after the time of maximum insolation
- Equinox and solstices
c. latitude
- sphere means that the sun’s rays will strike earth at different angles
- low latitudes warmer that mid-latitudes warmer than high latitudes
- PICTURES pg. 375
B. Characteristics of a material affect both how much energy a material absorbs as well as how the absorbed material affects temperature. (oceans)
C. Sun’s angle affects insolation intensity
a. spread out vs. concentrated
D. Cloud cover
a. absorb, reflect, scatter solar radiation
b. radiational cooling
2. Heating of Land and Water
A. Land heats faster and cools quicker that water
a. heat energy only concentrated on the surface
b. no evaporation, therefore more heat
B. Water heats slower and cools slower than land
a. evaporation
b. fluids are heated to a greater depth (meters vs. centimeters) than land (solids) due to clearness and convection currents
C. Specific heat of land vs. water
a. specific heat of water is three times greater than land
D. Different surfaces absorb heat differently
a. dark
b. light
c. rough
d. smooth
e. wet
f. dry
g. reflection of light (snow)
3. Temperature Maps
A. Isotherms
B. Picture on page 377
Chapter 17 – 4 HUMAN IMPACT ON THE ATMOSPHERE
Objectives:
- Understanding of how human activities can affect the atmosphere
- Compare and contrast acid rain, smog, ozone depletion, and global warming
1. Common Air Pollutants
A. Air pollutant
B. Natural air pollutants vs. man made air pollutants
C. Chart on page 378 = pollutants and effects on the atmosphere and humans
2. Acid Rain
A. pH scale
B. Acid rain/precipitation affecting the environment
C. Acid rain/precipitation affecting man made structures
3. Smog
A. Smoky fog or photochemical fog
B. Ground level ozone created from pollution and it’s effects on Earth
C. Temperature inversions and their effect on smog pollution
4. Ozone Depletion
A. Layer of ozone in the stratosphere that protects the Earth from ultraviolet radiation
B. CFC’s
C. Health effects resulting from the ozone “hole” found at the poles
D. Montreal Protocol on Substances that Deplete the Ozone Layer
5. Global Warming
A. Human activities affect global warming
a. deforestation
b. fossil fuels
c. greenhouse gasses
B. Global Warming Effects
a. sea level
b. storms and hurricanes
c. heat and drought
d. relocation of climate zones