and the Impact on Living Things Earths Atmosphere The gases that surround Earth and other planets make up the atmosphere These gases are like an envelope that protects us from the radiation that is caused by the suns ID: 490551
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Slide1
Composition of the Atmosphere Through Time
and the Impact on Living ThingsSlide2
Earth’s Atmosphere
The gases that surround Earth (and other planets) make up the atmosphere
These gases are like an envelope that protects us from the radiation that is caused by the sun’s raysThe functions of the atmosphere include protection from the sun, maintaining temperature, and supplying gases necessary for breathing.Slide3
Layers of the Atmosphere
The atmosphere is divided into
four
layers based on
temperature, air pressure, and other
properties
.
Troposphere (closest to Earth)
StratosphereMesosphereThermosphere (ionosphere and exosphere)Slide4
Layers of the AtmosphereSlide5
The Thermosphere
The
thermosphere
is the uppermost layer with temperatures that increase as altitude increases.
Made up of the ionosphere and exosphere
auroras happen in the ionosphere
sattelites orbit in the exosphere
Hottest of the layers
Air is very thin (the air is only about 0.001 percent as dense as the air at sea level) Slide6
The Mesosphere
The
mesosphere
is between the thermosphere and stratosphere.
Temperatures decrease as altitude increases
.
Coldest layer
Meteoroids begin to burn up in the mesosphere
.Radio waves deflected back to Earth in this layerSlide7
The Stratosphere
The
stratosphere
is between the mesosphere and troposphere.
Temperatures generally increase as altitude increases.
Ozone
(O
3
) in the stratosphere absorbs ultraviolet radiation from the sun, which warms the air.Jets fly in this layerJet streams (“rivers of air”) are found in this layerSlide8
The Troposphere
The
troposphere
is the lowest layer of the atmosphere.
Temperature generally decreases as altitude increases. Temperatures near the surface vary greatly.
The troposphere contains 80 percent of the atmosphere’s total
mass.
All
weather happens in the troposphere.Slide9
QUIZ TIMESlide10
What are the layers of the atmosphere?
How do temperatures differ with altitude in the atmosphere?Slide11
EXOSPHERESlide12
MESOSPHERESlide13
THERMOSPHERESlide14
TROPOSPHERESlide15
STRATOSPHERESlide16
THERMOSPHERE
OR THE IONOSPHERESlide17
MESOSPHERESlide18
Atmosphere Over Time
The composition of the atmosphere has changedSlide19
Earliest/First Atmosphere
It is
hypothesized that the earliest atmosphere was composed of mainly H2 and HeMost
likely these gases were lost to
spaceAs this is a hypothesis, percentages are unknownBased on this hypothesis, living things did not existSlide20
Represent with a Graph
Scatter two different colored M&Ms on your pie chartSlide21
Second Atmosphere
There is evidence to suggest that the gases that made up the second atmosphere were
H2O, CO2, SO2, CO, S
2
, Cl2, N2, H2, NH
3 (ammonia), and CH4 (methane) These gases were caused by early volcanoesThis atmosphere contained approximately 90% CO2, 5% N
2, and 2% - 5% trace gases Slide22
Second Atmosphere’s Impact on Living Things
As Earth cooled over time,
oceans formed Oceans are made of H2O (water) This
allowed for the first life
forms -- bacteria These ancient bacteria survived because they used CO2 (carbon dioxide) to photosynthesize
One of the products of photosynthesis is O2 (oxygen gas)Slide23
Represent with a Graph
90% (carbon dioxide)
5% (nitrogen gas)2-5% (trace gases)Slide24
Today’s Atmosphere
Our atmosphere contains approximately
78% N2, 21% O2, and
1% trace gases
N2 remains from the second ancient atmosphereCO
2 levels decreased to approximately 0.03%.CO2 (along with other gases) levels have a large impact on our climate because of its ability to trap heatWithout CO2, the Earth would be approximately 0
oFSlide25
Impact on Living Things
Plants and animals maintain the balance of
CO2 and O2 through the processes of photosynthesis
and
cellular respirationThis allows for the production of oxygen and the consumption of carbon dioxide Slide26
Represent with a Graph
78% (nitrogen gas)
21% (oxygen gas)1% (trace gases)Slide27
What Happens Next?
We will be looking at how human’s have impacted our atmosphere and therefore Earth.
Topics:Global WarmingGreenhouse Effect