Transcript 1.1 Earth*s Atmosphere Supports Life

1. WEATHER is the condition of the
atmosphere at certain place and time
a
layer of air that surrounds the
Earth
 Supports
 Has
and protects life
gases that keep the Earth warm
and transports energy
 Gases:
N 78%; O 21% and
trace gases [CO2, Argon and
others (less than 1%)]
 Tiny solid particles-dust and sand
 Water Vapor-can vary due to
weather (how much it rains)
◦ Condenses to form clouds also
 The
Carbon Cycle (Plants CO2
from us and we get O2 from
them)
 The Nitrogen Cycle
 The Water Cycle (evaporatecloud-rain-evaporate)
The atmosphere is a system that interacts
with other systems like the ocean
(hurricanes) and can add pollution to the
air.
 Volcanic
Eruptions
 Forest Fires
 Dust Storms
1.
2.
3.
Air has mass and therefore it has other
properties such as density and (air) pressure.
There is column of air above everything that
has mass (*since air has mass and has volume
, it affects density)
Barometer: Measures air pressure in
a. Mercury Barometer-measures in inches
b. Aneroid Barometer-”without liquid”; millibars
4. Altitude-distance above sea level
 air becomes thinner as altitude increases.
It affects both air pressure and density
 Pressure decreases as altitude increases (as
we go up pressure goes down-less air mass)
 Density (mass/volume) decreases as altitude
increases because of fewer molecules in air
1. Troposphere-means to “turn over”; Air is
constantly circulating as warm air rises-cools and
falls
a. 0-12 km
b. Temperature decreases with altitude can get
as cold as -60 º C
c. 80% of total atmosphere mass-most water
vapor
d. Weather occurs in this layer
e. contains all life
f. Airplanes fly here
2.
Stratosphere
a. 10-50 km
b. Drier
c. Contains the ozone layer which protects
life from harmful UV rays (concern that
we are destroying the ozone layer)
-Ozone absorbs energy from the Sun and
it makes temperature rise
d. It is warmer than troposphere because air
is thinner and closer to Sun
e. Fast-moving air called jet stream
f. Weather balloons
3.
Mesosphere
a. 50-90 km
b. very thin air
c. most meteors enter this layer and burn up
d. Very cold because there are very few air
molecules
4. Thermosphere
a. 90+ km
b. less dense as it approaches space
c. very hot because it absorbs more of the Sun’s
radiation but still feels cold because molecules are
spread out
d. Two sub-layers
1.
2.
Ionosphere-Auroras occur here because the close
contact with Sun’s rays “charges” air molecules making
them ions
Exosphere-extends out into space; very thin; satellites
1.
2.
3.
Air Pollution-Harmful materials that are
added to the air
It can be moved around by wind
Types


Gases-carbon monoxide, methane, ozone,
sulfide oxide, nitrogen oxide
Particulates-solids like dust, pollen, etc.
4. Effects of pollution: irritated eyes, nose, throat
and lungs causing damage; can make it very hard
to breath; can stick to surfaces and cause damage
to plants buildings and other objects
4. Sources of Pollution
 Human
 Fossil Fuels-fuels from the
remains of animals and plants
 Smog-combination of smoke and
fog; bad in big cities
 Farming: fertilizers and pesticides
 Construction
 Factories
 Natural-volcanoes, forest fires,
dust, dirt, pollen
Greenhouse Gases are mixed layers of CO2,
methane, water vapor , nitrous oxide and
other gases which absorb and emit infrared
radiation creating the greenhouse effect (a
warming of the Earth) are increased by
human activities
***See pg. 25 in text
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