Transcript Living Things

The Atmosphere
Table of Contents
The Air Around You
Air Pressure
Layers of the Atmosphere
Energy in Earth’s Atmosphere
Heat Transfer
Winds
Composition of Earth’s Atmosphere
Earth’s atmosphere consists of nitrogen, oxygen, carbon dioxide,
water vapor, and other gasses as well as particles of liquids and
solids.
Nitrogen is the most abundant at approximately 75% of the air but
must be fixated through plants before animals can use it.
Oxygen makes up roughly 21% of the atmosphere and is directly
taken in by plants and animals.
Carbon dioxide makes up about 1% of the atmosphere and is
essential to plant life. Fuels like goal and gasoline release carbon
dioxide into the atmosphere.
Argon is an element that makes up 1% of the atmosphere.
Trace elements and dust particles make up the remaining elements
in the atmosphere.
The Air Around You
Gases in the Air
Which circle graph shows the correct percentage of gases in the
atmosphere? How should each portion of the graph be labeled? What
would be a good title for the graph?
Air Pressure
http://www.nasa.gov/audience/fore
ducators/topnav/materials/listbytyp
e/What_is_Atmospheric_Pressure.
html#.VNFFX5RdXnh
Because air has mass, it also
has other properties including
density and pressure.
Density – amount of mass in a
given volume of air.
Air pressure – result of the
weight of a column of air
pushing on an area.
Air Column
The weight of the column of air
above you puts pressure on you.
How does pressure from air
molecules keep you from being
crushed?
Measuring Air Pressure
We use a barometer to measure air pressure.
We measure air pressure in millibars.
Mercury Barometer: long glass
tube open ended while resting in
a dish of mercury.
Aneroid Barometer: airtight
metal chamber that is sensitive
to changes in air pressure
Altitude Affecting Density & Air Pressure
Altitude, or elevation, is the distance above sea level.
Air pressure decreases as altitude increases. As air
pressure decreases, so does its density.
Layers of the Atmosphere
http://www.brainpop.com/science/earthsystem/earthsatmosphere/
Scientists divide Earth’s
atmosphere into four
main layers classified
according to changes in
temperature.
The four layers are the
troposphere, the
stratosphere, the
mesosphere, and the
thermosphere.
Layers of the Atmosphere
Troposphere and
Stratosphere
Earth's weather
occurs in the
troposphere. The
stratosphere
contains the
ozone layer.
http://www.brainpop.com/science/eart
hsystem/ozonelayer/
Layers of the Atmosphere
Mesosphere
and
Thermosphere
The mesosphere
protects Earth’s
surface from
being hit by most
meteoroids. In
the
thermosphere,
the air is thin and
you cannot feel
heat.
Begin Your Homework
Pages 428-431
Altitude, Temperature, Observations for each
layer of the atmosphere
Layers of the Atmosphere Poster 2/7
With your group, complete the
“Layers of the Atmosphere” poster
activity. This will be due at the end
of class.
If you finish early, begin working on the
poster questions. What is not finished
is homework.
Radiation from the Sun
Energy travels to Earth as electromagnetic waves, a form of
energy that can move through the vacuum of space. Most of
the energy from the sun travels to Earth in the form of visible
light and infrared radiation (longer wavelengths than red light).
A smaller amount arrives as ultraviolet radiation (shorter
wavelengths than violet light).
What are the types of electromagnetic radiation in the
diagram?
Energy in Earth’s Atmosphere
Some sunlight is absorbed or
reflected by the atmosphere
before it can reach the surface.
The rest of the wavelengths
pass through the atmosphere to
the surface. wavelengths reach
Earth’s surface.
Clouds act as mirrors dispersing
sunlight in all directions,
scattering the light back into
space.
Why is the sky blue?
So… why is the sky blue?
A clear cloudless day-time sky is blue because molecules in the
air scatter blue light from the sun more than they scatter red
light.
When we look towards the sun at sunset, we see red and orange
colors because the blue light has been scattered out and
away from the line of sight.
Energy in Earth’s Atmosphere
Materials at Earth's surface reflect different amounts of
energy. How would you use the higher percentages below
to show a bar graph?
Energy in Earth’s Atmosphere
Complete each
sentence with a word
from the Word Bank
to learn what is
happening to the
energy at Earth's
surface and in the
lower atmosphere.
Greenhouse Effect in Earth’s Atmosphere
The greenhouse effect is
a natural heat-trapping
process in which radiated
heat is absorbed by
gases such as methane,
water vapor, and carbon
dioxide.
What is the sequence of
events that causes it to
occur?
Heat Transfer
Temperature is the average amount of energy of motion of
each particle of a substance. We use thermometers to
measure air temperature.
The metric temperature scale is Celsius where 00C is freezing
and 1000C is boiling.
The Fahrenheit scale is the US scale where 320C is the
freezing point and 2120F is boiling point.
How is Heat Transferred?
Winds
Differences in air pressure cause the air to move. Wind is the
movement of the air parallel to Earth’s surface, and always
moves from an area of high pressure to an area of low
pressure.
Most differences in air pressure are caused by the unequal
heating of the atmosphere. Air over heated surfaces expand
and become less dense; cool, more dense air flows underneath
the warm, less dense air.
We measure wind by looking at their direction and speed. Wind
vanes measure direction (north, south, east, west) and
anemometers measure wind speed.
Local Winds
Winds that blow over short distances are called local winds
that are caused by the unequal heating of Earth’s surface
within a small area (typically near bodies of water).
Global Winds
Winds that blow steadily from specific directions over long distances
are global winds. Like local winds global winds are created by the
unequal heating of Earth’s surface, but these occur over a large
area.
Where does the
sun hit Earth
most (M) and
least (L)
directly?
Global Winds
The Coriolis effect causes global winds to rotate in a curve.
Global winds in the Northern hemisphere turn toward the
right and in the southern hemisphere curves toward the left.
Global Wind Belts
The Coriolis effect and other factors combine to produce a
pattern of wind belts and calm areas around Earth. Match the
descriptions of the global winds with their location on the globe.