Download Chpt. 23.1 Study guide

Chapter 23, section 1
Atmosphere →
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Characteristics of the Atmosphere
The atmosphere is a layer of gases and tiny particles that surrounds the
earth
Meteorology- study of the atmosphere and of the weather and climate
o Weather- short term conditions of the atmosphere
o Climate- long term conditions of the atmosphere
Composition of the
atmosphere →
The most abundant elements in air are nitrogen (N2) at 78%,
oxygen (O2) at 21%, argon at 0.9%, and carbon dioxide (CO2) at 0.04%
Water vapor is added to the air via evaporation from the oceans and
removed via condensation and precipitation
Water vapor amounts vary from dry (1%) to moist (4%)
Nitrogen cycle →
The nitrogen cycle is the movement of nitrogen from the air to the soil,
and to plants and animals. Some bacteria removes nitrogen from the air
for plants to use, other bacteria release it back to the air
Oxygen cycle →
The oxygen cycle is the movement of oxygen from the air to living things
Atmospheric
X pressure →
Atmospheric pressure (also called air pressure) is the weight of the gas
molecules above. Gravity pulls the air to Earth, so there is more air
pressure at sea-level than there is in the mountains
Atmospheric pressure is measured with an instrument called a barometer
Layers of the
atmosphere →
The atmosphere is divided up into four layers based on temperature
1) The troposphere:
o Atmospheric layer closest to earth’s surface that contains all life
o Layer that has weather
o Temperature decreases with increasing altitude
2) The stratosphere:
o Layer above the troposphere
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Layer that contains the ozone layer- a layer that absorbs harmful
UV radiation
Layer that most jets fly in because there is no weather
Temperature increases with increasing altitude
3) The mesosphere:
o Layer above the stratosphere
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Tropopause →
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Meteors burn up in the layer before reaching Earth
Temperatures decreases with increasing altitude (coldest layer)
thermosphere:
Layer above the mesosphere
Aurora borealis occurs in this layer
Temperatures increase with increasing altitude (hottest layer,
probably more than 2000°C
o This layer blends into outer space
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4) The
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In between each layer there are zones where the temperature remains
constant. These zones are named for the layer below them; the
zone above the troposphere is the tropopause, the zone above the
stratosphere is the stratopause, the zone above the mesosphere is the
mesopause