Atmosphere
Chapter 14
Earths Atmosphere
Section 14.1
What is the composition of the Earths Atmosphere?
Composition of the Atmosphere
Atmospheric Gases (clean, dry)
Nitrogen --------------78%
Oxygen ---------------21%
Argon -------------------0.93%
Carbon Dioxide --------0.03%
Others -------------------0.04
Composition of the Atmosphere
Atmospheric Gases (cont.)
water varies from 0 to 4%
Composition of the Atmosphere
Atmospheric Solids And Liquids
Dust
Salt
Ice
Liquid water
Give the layers of the Earths Atmosphere.
Structure of the Atmosphere
Troposphere -------Temperature decreases
Stratosphere -------Temperature increases
Mesosphere --------Temperature decreases
Thermosphere -----Temperature increases
Structure of the Atmosphere
Weather in Troposphere
Ozone layer between Stratosphere and Mesosphere; adds energy to those layers
Ionosphere ionized layer in the thermosphere that affects radio transmission
Atmospheric Pressure
Weight of Air = Atmospheric Pressure
Less Air above you with altitude less pressure
Atmospheric pressure at sea level
14.7 lb/in2
760 mm of mercury
29.92 inches of mercury
Atmospheric Pressure
Which air is heavier: dry or humid?
Atmospheric Pressure
H2O
H - 1X2 = 2
0 - 16
Total = 18
N2 - 28
O2 - 32
CO2 - 44
Atmospheric Pressure
Water molecules weigh less than air molecules. Thus humid air weighs less than dry air and has less
pressure.
Temperature in the Atmosphere
Hot air low pressure
Cold air high pressure
What is Ozone?
What is Ozone?
Molecule containing 3 atoms of oxygen. Most oxygen molecules have 2 atoms.
Why is the Ozone layer important?
Why is the Ozone layer important?
Blocks harmful Ultraviolet radiation which can cause cancer.
What causes the hole in the Ozone Layer?
What causes the hole in the Ozone Layer?
CFCs (Chlorofluorocarbons) destroy ozone molecules
Energy from the Sun
Section 14.3
Energy Transfer in the atmosphere
Radiation electromagnetic waves
Conduction molecules bump into one another
Convection flow of a heated material
Energy Transfer in the atmosphere
30% reflected back into space
70% insolation(incoming solar radiation)
20% absorbed by clouds and atmosphere
50% absorbed by earths surface
5% reflected by surface
25% reflected by clouds and atmosphere
Our Unique Atmosphere
Convection Currents transfer energy around our atmosphere
The Water Cycle
Evaporation
Condensation
Precipitation
Runoff or groundwater
Movement of air
Section 14.4
Wind Formation
Wind horizontal movement of air caused by differences in pressure
Wind Formation
Coriolis Effect
Deflects wind to right in northern hemisphere and left in the southern hemisphere
Temperature difference
Length of day
Angle of sun
Pressure difference
Wind blows from a high to a low pressure
Global Pressure Systems
Equatoral Low Equator
Subtropical high 30o
Subpolar low 60o
Polar high - Poles
Global Surface Wind Systems
Doldrums Equator
Trade Easterlies 30o to Equator
Horse Latitudes 30o
Westerlies 30o to 60o
Polar Easterlies Poles to 60o
High-Altitude Winds
Jet streams upper level wind systems
Daily and Seasonal Winds
Sea Breeze afternoon
Land Breeze early morning(night)
Mountain Breeze afternoon
Valley breeze early morning(night)
Daily and Seasonal Winds
Monsoons
Summer rainy
Winter - dry
Wind Systems
