Weather, Climate, and the
Atmosphere
Composition of the
Atmosphere
What is weather?
 Weather is the condition of the Earth’s
atmosphere at a particular time and
place.
– Example: What is the weather outside
right now?
– Not an Example – What is North
Carolina weather in the fall?
What is Climate ?
Climate is the general patterns of weather
a place experiences over time.
What Determines Climate
 Temperature
 Precipitation
Factors That Affect Temperature

Latitude: distance north and south of
equator
Areas close to the equator (0˚ latitude),
receive the direct rays of the sun. I57
What type of climate do these areas have?
Where do the lowest average temperatures
occur?
Near the Poles ( 90˚ north or south)
 Elevation (Altitude)
What becomes less dense as elevation
increases?
Less-dense air cannot hold as much heat
as denser air. What does this cause the
temperature to do?
(It decreases)
Ocean Currents
An ocean current is a “river” of water that flows
in a definite path in the ocean. I115
They are either warm or cold currents.
The surface temperature of water affects the
temperature of _____________?
Air above it
Ocean Currents
Currents traveling away from the equator
are warm water currents.
Currents traveling toward the equator are
cold water currents.
Factors That Affect Precipitation
 Prevailing Winds : A wind that blows
more often from one direction than from
any other direction.
Prevailing Winds
 Warm: holds more moisture
Warm air rises and then cools so it cannot
hold the moisture; therefore, it falls to earth
as some type of precipitation.
 Cold: holds less moisture
Cold air sinks and becomes warmer so it can hold
more moisture. Due to this there will be little
precipitation.
Prevailing Winds

Direction from which they blow
determines how much moisture it
carries
1. Land to water (land breeze)
2. Water to Land (sea breeze)
Which kind of wind carries more moisture?
Prevailing Winds
How can the Sahara desert exist near the
Atlantic Ocean and only receive less than
25 centimeters of rainfall? I116
Land and Sea Breezes
Why does land heat up and cool down faster than
water?
Soil and vegetation reflect less solar radiation than
water. The solar radiation heats up the very top of
the land surface. It cannot penetrate the soil at a
deep level.
Vegetation absorbs solar radiation and stores it for
energy.
Land and Sea Breezes
Water will reflect most of the solar radiation
back into the atmosphere. The remainder
can penetrate into the water
Monsoons
What is a monsoon?
The name "monsoon" is derived from the
Arabic word “mausim" which means
"season" or "wind-shift".
Monsoons
Sea and Land breezes over a large region
that changes direction with the seasons are
called monsoons. Page 56I
What is the Atmosphere?
Remember!
Atmos – Vapor
Sphere – Ball
The Atmosphere is a
layer of gasses that
surround Earth or any
planet.
Why is the atmosphere important:
1. We need the gases for survival.
2. It prevents the earth from being hit by
meteoroids
3. Heats the water on earth to keep most of
it in liquid form
4. Protects us from the
What is in our atmosphere?
Gases (dry air)
1. Nitrogen 78% - N2
2. Oxygen 21% - O2
What else is in the atmosphere?
3. Carbon Dioxide less than 1% - CO2
4. Trace Gases – less
than 1% of argon,
helium, methane,
krypton, & hydrogen
What else is in the atmosphere?
 Water Vapor – Water in the form of a gas
 The amount of water vapor varies from 0 –
5%.
 Example – Desert – O%
 Example – Rainforest – 5 %
What else is in the atmosphere?
 Particles
 Examples:
– Dust
– Smoke
– Salt
– Other Chemicals
Is it OK to be dirty?
 YES!! (to a certain degree)
 When water vapor condenses to form
clouds it must have something to stick to in
the atmosphere.
 Natural pollutants are just the thing that
clouds need.
Pollution
What is Pollution?
 Harmful substances in the
air, water or soil.
Is some pollution OK?


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
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YES!!
Salt Spray
Mold
Pollen
Erosion
Forest Fires
Dust Storm
Animal Dander
Volcanic Eruption
 These are all Natural
Pollutants.
BUT SOME IS NOT!!
 Un- natural
Pollution =
Human Activities
 ½ - motor
vehicles
 ¼ - factories and
power plant
 ¼ - farming,
construction,
burning fossil
fuels (wood and
coal)
Smog = Smoke + Fog
 London Smog – coal
particles + Water
Vapor in the humid air
in England
 Photochemical Smog sunlight + chemicals in
the air released by
motor vehicles and
factories
Acid Rain
 Chemicals called
oxides mix with water
in the air to make the
rain acidic (Draw this)
 Precipitation carries
acid from the air to
trees, water sources,
and buildings
NOW WHAT?
 Pollution Restrictions
by US Government
 Higher standards for
clean cars
 More affordable and
reliable Hybrid/electric
vehicles