Atmosphere Study Guide
Composition of the Atmosphere
Name 2 functions of the atmosphere:
Earth’s atmosphere makes Earth livable in many ways:
 Protects/sustains life on Earth
 Provides oxygen for breathing
 Carbon dioxide for plants (photosynthesis)
 Water vapor for precipitation
 Ozone layer absorbs ultraviolet solar radiation
Be able to read a circle graph.
Describe the difference between:
Major vs Trace gases (give examples of each)
Trace gases, such as argon,neon, carbon dioxide are present in such small concentrations
less than 1%.
Permanent vs Variable gases (give examples of each)
Variable gases, such as water vapor, vary (or change) in their amounts.
Think desert vs. rain forest
Permanent gases’ amounts never change, such as Nitrogen.
What is the most common gas in the atmosphere?_____Nitrogen 78%___
What is the second most common gas in the atmosphere?____Oxygen 21%_______
How has the Earth’s atmosphere changed compared to Earth’s early atmosphere? Why did these
changes occur?
___ The atmosphere we enjoy today is radically different from the atmosphere that formed with
the Earth billions of years ago.
The Earth formed with an atmosphere of hydrogen and helium. Because the Earth didn’t have a
magnetic field (magnetosphere) to protect it yet, the intense solar wind from the young Sun blew this
early atmosphere away. Volcanos spewed out gasses-water vapor, carbon dioxide and ammonia. This
early toxic atmosphere was nothing like the atmosphere we have today. Light from the Sun broke down
the ammonia molecules released by volcanos, releasing nitrogen into the atmosphere. Photosynthetic
cyanobacteria – use energy from the Sun for photosynthesis, and release oxygen as a byproduct. They
also take in carbon dioxide to make sugar (just like plants, algae, and cyanobacteria) continue to do this
today.
Heat in the Atmosphere
Review the indirect/slanted and direct rays activity.
What part(s) of the globe receive direct rays? ________equatorial regions_____________
What part(s) of the globe receive indirect/or slanted rays? ______polar regions_____________
Do direct or slanted rays produce more intense heat?_________direct_____________________
Describe reflection, scattering, and the absorption of heat.
__reflect: send back_____________________________________________
__scatter: change direction___________________________
__absorb: take in______(often absorbed energy can be re-radiated as heat)_______
Give examples of surfaces that reflect more heat, and absorb more heat.
Which type of surface will get hotter?
___All surface absorb and reflect light. The more of the suns rays that are absorbed the higher
the hotter the object will get. Snow reflects about 80% charcoal reflects about 4%.______
Describe the greenhouse effect. (HINT: It is natural. Do not use the words pollution or global warming.)
The greenhouse effect is a naturally occurring process that aids in heating the
Earth's surface and atmosphere. It results from the fact that certain atmospheric
gases, such as carbon dioxide, water vapor, and methane, are able to change the
energy balance of the planet by absorbing radiation. Without the greenhouse effect
life on this planet would probably not exist as the average temperature of the Earth
would be a chilly -18° Celsius, rather than the present 15° Celsius. The thicker the
atmosphere is with these heat absorbing gases the warmer the globe will be and the
less heat will escape into space. Humans can “thicken” the atmosphere and
strengthen the greenhouse effect by adding greenhouse gases.
Heat transfer occurs through 3 methods what are these methods?
____heat moves from warmer areas to cooler areas by radiation, conduction, and convection____
Draw, label & describe a convection current: (use some form of the word density in your description)
Density is a measure of how much mass there is in a
volume of a substance. If an object is less dense than water, it will
float to the top. If an object is more dense than water, it will sink
to the bottom. Convection: circulation of molecules in gases or
liquids due to differences in density. This only works in liquids
and gases because it requires matter that can move or flow.
Example: magma in the mantle, ocean currents, the suns
convection currents, a space heater, the Earths major winds.
Define & give an example of conduction:__ Conduction: the transfer of heat between molecules that
are in direct, physical contact with one another. Example: spoon gets hot in hot soup, your hand warms an ice
cube.
Define & give an example of radiation:___energy that can be transferred as waves through empty space in all
directions, once absorbed it can be changed to heat and released__
Example: fireplace, french-fry warmer lights, the sun, the asphalt at night
When heat is __ (absorbed
the environment.
/
reflected) _ by a surface it can later be __radiated____ back into
Layers of the Atmosphere
Know the order and characteristics of each layer.
Earth is about 10 times larger than its atmosphere.
Troposphere: lowest, most dense, thinnest layer of the atmosphere; where we live, air is most
dense at the bottom and less dense at the top. Air that is less dense absorbs less heat.
Stratosphere: where jets fly; contains ozone layer
Ozone layer: absorbs heat and blocks Ultraviolet light (UV rays)
Mesosphere: coldest layer, where meteor showers occur, does not absorb heat
Thermosphere: air is very thin; space shuttles orbit here
Ionosphere: auroras(light displays), made of ions(charged particles), AM radio waves
Exosphere: outer space
Describe and interpret a graph of the temperature of the atmosphere at different altitudes.
Does this layer increase (I) or decrease (D) in temperature with increasing altitude?
Troposphere ___D_____
Stratosphere ___I____ Mesosphere __D_____ Thermosphere___I______
Why does this pattern occur? What makes some layers get colder and others get hotter? BE SPECIFIC.
Each layer contains different kinds of gases (the dense gases are at the bottom). Some gases
absorb heat more than others.
Troposphere: air is most dense at the bottom and less dense at the top. Air that is less dense
absorbs less heat.
Stratosphere: Ozone layer: absorbs heat
Mesosphere:, does not absorb heat
Thermosphere: close to the sun interacts with solar radiation. made of ions(charged particles),
What happens to temperature at the “pauses”:_ At a pause in the atmosphere, such as the tropopause,
temperature stops increasing/decreasing. Pauses separate the layers.
What are the 2 layers of the thermosphere?____ionosphere and exosphere____
Where is the ozone layer and what does it do?__stratosphere; blocks UV rays and absorbs heat_______
Water Cycle
Review the Cloud Making Lab and Water Cycle Game.
Describe and label the steps in the water cycle.
Label: Sun, condensation, precipitation, runoff, ground water, transpiration, respiration, evaporation, excretion
Condensation is the process by which water vapor changes to liquid to water.
Evaporation is the process by which liquid water turns to water vapor (gas).
Groundwater is water that is held in rock layers under the surface of the Earth.
Precipitation is the process by which water falls from the atmosphere to Earth’s surface.
Runoff is water flowing over the surface of the Earth. Flow: movement of water down a river or under
the ground to a different location.
Transpiration is the process by which water evaporates from the leaves of plants.
Respiration: the process by which organisms take in oxygen and sugar and produce energy. They then
release carbon dioxide and water vapor. When you exhale water vapor enters the atmosphere.
Excretion: Wastes, like excess water, is released from the bodies of organisms as urine, sweat and in
feces.
Drinking/absorption into roots: water enters the bodiesd of organisms
Infiltration: water enters the soil
Percolation: water flows through the pores in the soil
Collection: Water stops flowing and “pools” into lakes, streams and oceans.