Transcript Composition of the Atmos#AC

Composition of the
Atmosphere
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Meteorology- The study of the entire
atmosphere, including its weather.
Weather- The daily condition of the Earth’s
atmosphere.
The atmospheric factors that interact to
cause weather are Winds, Heat Energy,
Moisture, and Air Pressure.
Wind
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What is the name of the scale that relates
wind speed to its effect?
Beaufort Scale
Sometimes the temperature will actually
feel colder than it actually is due to?
Windchill Factor
Cont.
Ex. If the temperature was 25 F and the
wind was blowing at 35 mph, the
temperature would feel like 7 F and there
would be great danger that exposed flesh
would freeze
Heat Energy
• Almost all of Earth’s energy comes from
the Sun. This energy is called radiant
energy. Even though the Earth only
receives about 1/2,000,000,000 of the
suns rays, it is enough to keep it warm.
Cont.
• Sun’s energy – Transferred by
Radiation
• 30% - reflected back into space by
atmosphere or by surface of Earth.
• 19% - absorbed by atmosphere.
• 51% - absorbed by Earth’s surface.
• Some heat is then conducted through the
ground thereby heating the lower layer of
air.
• Through the process of convection, that
lower heated air can then rise as cooler,
heavier air takes its place.
• When the sun’s energy reaches Earth, Much of it
is converted into infrared or heat rays . Infrared
rays cannot pass back out through the
atmosphere. It is held in by CO2, Water Vapor,
and other gases. This is called the Greenhouse
effect because the gases act like the glass that
traps in heat in a greenhouse. The burning of
fossil fuel is constantly adding CO2 to the air.
This causes more infrared rays to be absorbed.
• What could this do to temperatures on Earth?
Go up
• What other problems might it cause?
-Glaciers could melt, raising sea level and
causing flooding; change in rainfall pattern.
Temperature Variations
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If the Earth’s atmosphere is warmed by heat rising
from the surface how can air temperature vary so
much from place to place?
1. Angle of sun’s rays (seasons)
-at equator, rays strike at 90. Since it gets most direct
rays it is hotter.
2. Day and night
-Obviously there is more direct sunlight during day
compared to night.
3. Cloudy and Clear Days
-More sun on clear days
4. Type of Surface
Water heats up slower but cools slower than land.
• Normally, air gets
colder with height in
the troposphere. In
fact, the air usually
cools 1 F for every
160 meters up. This
constant change is
called lapse rate.
• Occasionally, cold air
gets caught under a
layer of warm air.
This upside-down
condition is called a
temperature inversion
Temperature inversions can cause
smoke and other pollutants to get
trapped beneath the warm air. Why do
you think this pollution is especially
harmful in cities in basins (like Los
Angeles) and beside mountain ranges
(like Denver)?
•Because horizontal winds cannot
easily carry the polluted air away.
Air Pollution
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Definition:
– Any substance in the atmosphere that is
harmful to people, animals, plants, or
property.
Main source of air pollution:
– Burning of fossil fuels
Pollutants
• Smog- smoke and fog (air pollution + moist
air)
• Carbon Monoxide- Colorless, odorless,
poisonous gas (from cars)
• Manmade ozone- Nitrogen, oxygen, suns
rays.
• Nitrous Oxide- gas produced to put people
asleep.
• Hydrocarbons- Produced by burning fossil
fuels
Measuring Air Temperature
• Air temperature is
measured with:
– Thermometer
– Bimetal Thermometer
– Thermograph – self
recording
thermometer.