The Atmosphere
 Air is a MIXTURE of gases.
 Nitrogen = 78%
 Oxygen = 21%
 Argon = < 1%
 CO2 = .039%
The Atmosphere
 Components of Air
1. Gases
2. Water vapor
a.
b.
Varies 0 – 4%
Depends on location and weather pattern
3.
Aerosols (solids and liquids suspended in air)
4.
Ozone
a.
b.
3 atoms of oxygen bonded together. O3
Ozone layer located at the top of the Stratosphere
Structure of Atmosphere
 Air Pressure
 Decreases as you rise in altitude
 Average = 1013.2 mb (millibars)
 Measured with a barometer
Structure of Atmosphere
 4 layers based on
temperature change.
 Troposphere
 Layer we live in
 Temp. decrease
 Stratosphere
 Ozone layer here
 Temp. increase
 Mesosphere
 Coldest
 Thermosphere
 Space shuttle
 Hubble telescope
 Temp. increase
Atmospheric Heating
 Heating of the Atmosphere from the Sun’s energy.
 3 methods of heat transfer
Energy Transfer
1.
Conduction
a. by contact of molecules
2.
Convection
a. By different densities of
air (hot/cold)
3.
Radiation
a. By electromagnetic
waves
Surface
GREEN HOUSE EFFECT
 Incoming radiation
 Mostly visible light
 Gets absorbed by surface
 Changed to Infrared (heat)
 Greenhouse gases:
 H2O
 CO2
 Absorb Infrared heat and keep air
near surface warm.
 Increase of Greenhouse gases
 Causes increase of heat trapped
 Called Global Warming
Ozone Layer
 Ozone Layer
 O3
 Absorbs UV rays from sun


Changes it to heat
Causes increase temperature in
stratosphere
 Ozone Problem
 O3 layer is getting thinner
 Broken up by CFC’s
(chlorofluorocarbons)
 Causes increase UV rays to reach
surface (increase skin cancer)
Atmospheric Energy Budget
 What happens to the Energy of the Sun as it hits the
atmosphere?
Of the total energy that
strikes our atmosphere:
100%
•Radiation absorbed by
clouds or atmosphere?
20%
•Total scattered and
reflected back to space?
30%
•Absorbed by Earth’s
surface?
50%
Affect of Surface Material
 Albedo: Reflectivity of the surface
 High Albedo = Very reflective, poor
absorber
 Low Albedo = Good absorber, poor
reflector
 Color:
 Darker color = good absorber = Low
Albedo
 Light color = good reflector = High
Albedo
Effect of Surface Material
Land Verses Water




Which heats up the quickest?
Which heats to a higher temperature?
Which will cool down the quickest?
Which will cool to a cooler temperature?
 How does this temperature change affect where you live?
Effect of Surface Material
How does living near the ocean affect the air
temperature?
 Winter?
 Summer?
How does living inland affect the air temperature?
 Winter?
 Summer?
Which location would have a greater change of
temperature during the year?
Moisture in the Atmosphere
 Humidity = Amount of water vapor in the air
 5g H2O/kg of air
 Saturated air = Holding all the water vapor it can hold.
 Capacity = The amount of something it can hold
 When something is filled to CAPACITY it is SATURATED.
Water vapor Capacity or Air
Direct Relationship:
As air temperature INCREASES, its
water vapor capacity INCREASES.
Moisture in the Atmosphere
 Relative Humidity = The amount of water vapor in the
air compared to how much it can hold at that
temperature.
 Given as a % of fullness.
 As the temperature changes throughout the day, so does
the Relative Humidity.
Moisture in the Atmosphere
 Dew-point Temperature: The temperature the air must
cool down to for the water-vapor in the air to condense as
liquid onto objects.
 Usually occurs in the evening as the temperature decreases.
 Relative humidity =
 Air is
%
(holding all the water-vapor it can
hold)
 More humid air = higher dew-point temperature
 What do you call it when the dew-point is below freezing?
Moisture in the Atmosphere
Clouds
 Classified by:
1. Height above
ground



Low
Middle
High
2. Appearance



Layered
Puffy
Wispy
Clouds
 Cloud TYPE roots:
1.
Cirro = curly
2.
Cumulo = puffy(heaped)
3.
Strato = layered
4.
Alto = middle level
5.
Nimbo/bus = rain
Draw here:
Clouds
 Classification of clouds
 Cirro = High and wispy
 Stratus = cover whole sky
 Cumulo = clumpy (puffy)
 Examples:
 Cirrocumulus =
 Altocumulus =
 Cirrostratus =
 Nimbostratus =
 Cumulonimbus =
Description:
Name each cloud type:
Cumulonimbus cloud = Thunderstorms
Thunderstorm:
•Heavy down
pour of rain
•Thunder and
lightning
•Gusty winds
•Hail
•Tornado
possible
Cumulus
clouds
Updraft
builds vertical
Breaks
up