The document discusses the composition and layers of Earth's atmosphere. It begins by explaining that the atmosphere protects Earth and drives weather patterns. It is composed primarily of nitrogen, oxygen, and traces of other gases. Early atmospheres lacked oxygen but organisms began producing it over billions of years, forming an ozone layer. The atmosphere has five main layers - troposphere, stratosphere, mesosphere, thermosphere, and exosphere - defined by temperature trends. Solar radiation and the greenhouse effect warm the atmosphere, while convection currents driven by temperature differences and the Coriolis effect produce global wind patterns like the trade winds and jet streams that influence weather. Clouds form through condensation in rising air.

2. Solar Energy as Radiation
Figure 1.1
Nearly 150 million kilometers separate the sun and earth, yet solar
radiation drives earth's weather.

3. Earth's Atmosphere
The Atmosphere is a thin layer of air that protects the
Earth’s surface from extreme temperatures and
harmful sun rays
Figure 1.2
Thin Gaseous envelope

4. Composition of Atmosphere
(Mixture of gases, solids, and liquids)
• Early atmosphere was much different than
today
• Volcanoes produced nitrogen and carbon
dioxide, but little oxygen
• More than 2 billion years ago, early
organisms began producing oxygen
• Eventually, oxygen formed an ozone layer
that protected Earth from harmful rays
• Green plants and diverse life forms
developed

5. Atmospheric Gases
(Mixture of gases, solids, and liquids)
• Nitrogen - 78%
• Oxygen - 21%
• Water Vapor – 0 to 4%
• Used for clouds and precipitation
• Carbon Dioxide - .037%
• Keeps Earth warm and is used by
plants to make food
• Argon - .93%
• Traces of neon, helium, methane,
krypton, xenon, hydrogen, and ozone

6. Atmospheric Gases
(Mixture of gases, solids, and liquids)
• Atmosphere is changing with the
introduction of pollutants; increasing
human energy use is increasing the
amount of carbon dioxide
• Pollutants mix with oxygen and other
chemicals to form smog
• Aerosols include solids such as
dust, salt, and pollen
• Liquids include water droplets and
droplets from volcanoes

7. Five Layers of the Atmosphere

8. Atmospheric Layers
8 layers are defined by constant trends in
average air temperature (which
changes with pressure and
radiation), where the outer
exosphere is not shown.
1. Troposphere
2. Tropopause
3. Stratosphere
4. Stratopause
5. Mesosphere
6. Mesopause
7. Thermosphere
8. Exosphere

9. Atmospheric Layers
Figure 1.7
Troposphere – Temp decrease w/
heightMost of our weather occurs in this
layerVaries in height around the globe,
but Averages about 11 km in height.
Tropopause separates Troposphere
from Stratosphere. Generally higher in
summerLower in winter.

10. The troposphere is the lowest major atmospheric layer, and is located from the
Earth's surface up to the bottom of the stratosphere. It has decreasing temperature
with height (at an average rate of 3.5° F per thousand feet (6.5 ° C per kilometer);
whereas the stratosphere has either constant or slowly increasing temperature with
height. The troposphere is where all of Earth's weather occurs. The boundary that
divides the troposphere from the stratosphere is called the "tropopause", located at
an altitude of around 5 miles in the winter, to around 8 miles high in the summer,
and as high as 11 or 12 miles in the deep tropics. When you see the top of a
thunderstorm flatten out into an anvil cloud, like in the illustration above, it is usually
because the updrafts in the storm are "bumping up against" the bottom of the
stratosphere

11. Atmospheric Layers
Figure 1.7
Stratosphere - Temperature inversion
in stratosphere. Ozone plays a major
part in heating the air at this altitude

12. Atmospheric Layers
Figure 1.7
Mesosphere
Middle atmosphere – Air thin, pressure
low, Need oxygen to live in this region.
Air quite Cold -90°C (-130°F) near the
top of mesosphere

13. Atmospheric Layers
Figure 1.7
Thermosphere
“Hot layer” – oxygen molecules
absorb energy from solar Rays
warming the air. Very few atoms
and molecules in this Region.

14. The Stratosphere and Ozone Layer
Above the troposphere is the stratosphere, where air flow is mostly horizontal. The thin ozone layer in the
upper stratosphere has a high concentration of ozone, a particularly reactive form of oxygen. This layer is
primarily responsible for absorbing the ultraviolet radiation from the Sun. The formation of this layer is a
delicate matter, since only when oxygen is produced in the atmosphere can an ozone layer form and prevent
an intense flux of ultraviolet radiation from reaching the surface, where it is quite hazardous to the evolution of
life. There is considerable recent concern that manmade flouro carbon compounds may be depleting the
ozone layer, with dire future consequences for life on the Earth.
The Mesosphere and Ionosphere
Above the stratosphere is the mesosphere and above that is the ionosphere (or thermosphere), where many
atoms are ionized (have gained or lost electrons so they have a net electrical charge). The ionosphere is very
thin, but it is where aurora take place, and is also responsible for absorbing the most energetic photons from
the Sun, and for reflecting radio waves, thereby making long-distance radio communication possible.

16. The Ozone Layer
above your head, lies an
atmospheric layer called the
ozone layer.
• Within the stratosphere, about 19 km to 48 km
• Ozone is made of oxygen.
• Although you cannot see the
ozone layer, your life depends on
it.

17. The Ozone Layer
• An ozone molecule is made up of three oxygen atoms
bound together.
• The ozone layer contains a high concentration of ozone
and shields you from the Sun's harmful energy.
• Ozone absorbs most of the ultraviolet radiation that enters
the atmosphere.
• Ultraviolet radiation is one of the many types of energy
that come to Earth from the Sun.

18. CFCs
• Evidence exists that some air pollutants are destroying the
ozone layer.
• Blame has fallen on chlorofluorocarbons (CFCs), chemical
compounds used in some refrigerators, air conditioners, and
aerosol sprays, and in the production of some foam packaging.
• Chlorofluorocarbon molecules destroy ozone.
• When a chlorine atom from a chlorofluorocarbon molecule comes
near a molecule of ozone, the ozone molecule breaks apart.
• One of the oxygen atoms combines
with the chlorine atom, and the rest
form a regular, two-atom molecule.

19. •Some of the Sun’s
energy coming
through Earth’s
atmosphere is
reflected or absorbed
by gases and/or
clouds in the
atmosphere.

20. Greenhouse Effect
•Solar energy that is
absorbed by the Earth’s
land and water is
changed to heat that
moves/radiates back
into the atmosphere
(troposphere) where
gases absorb the heat,
a process known as the
greenhouse effect.

21. Greenhouse Animation

22. Energy is transferred between fast-
moving molecules and slower-moving
molecules
• CONDUCTION – transfer of energy
when molecules collide
• CONVECTION – occurs when warm
air rises and cool air sinks; it’s the
transfer of heat, usually in liquids or
gases

23. Air Movement
• Wind: Movement of air from one temperature or
pressure area to another
• Different areas of Earth receive different
amounts of the Sun’s energy
• Equator’s warm air, being less dense, is
pushed upward by denser, colder air
• Poles’ cold air, being more dense, sinks and
moves along Earth’s surface
• CORIOLIS EFFECT: spinning of the
Earth causes moving air to turn to the
right in the northern hemisphere and to
the left in the southern hemisphere

24. Global Winds
• Wind patterns, caused by convection currents combined
with the Coriolis effect, of Earth that affect the world’s
weather
• Near equator, very little wind and daily rain patterns
called the doldrums
• Surface winds:
• Between equator and 30 degrees N and S latitude
are steady trade winds
• Between 30 and 60 degrees N and S latitude, the
westerlies blow in opposite direction from the trade
winds.
• The polar easterlies blow from northeast to
southwest near the north pole and from southeast
to northwest near the south pole

25. Global Winds
Equatorial doldrums
TRADEWINDS
TRADEWINDS

26. The Weather Highways
• The rotation of the
earth creates the
Coriolis effect.
• The Coriolis effect
causes the air and
water to be
deflected to the
right north of the
equator.
• This creates global
weather highways

27. The Westerlies
• Because of our
latitude, most
of our weather
comes from
the west
• Looking at the
weather map,
what type of
weather might
we expect?
• What type of
weather might
we expect in a
few days?

28. After the atmosphere is warmed by
radiation and conduction, the heat is
transferred throughout the atmosphere by
convection.
• Since warmed air
has more space
between the
molecules, it’s
less dense and
rises
• Cooled air is more
dense and tends
to sink
• In general, air
near the equator
tends to rise and
air near the poles
tends to sink

29. Take a look at this!

30. Why do you think there is this band
of clouds near the equator?

31. Notice the band of
clouds around the
equator ?
This is the ITCZ or inter
tropical convergence zone

32. Clouds
• Form when air rises, cools to its dew point, and
becomes saturated
• Shape and height of clouds vary with temperature,
pressure, and water vapor in atmosphere
• Warm, moist air in the
tropics rises
• Cold air can hold less
moisture than warm air
• As the moist air rises, it
condenses and forms clouds!
Did you figure it out?

33. Types of Clouds
As to Shape:
1. Stratus-smooth, even sheets or layers at low
altitudes
2. Cumulus-puffy, white clouds, often with flat
bases
3. Cirrus-high, thin, white feathery clouds made
of ice crystals
4.Nimbus - clouds are dark and so full of water
that sunlight can’t penetrate them
As to Height:
a. Cirro – high clouds
b. Alto – middle-elevation clouds
c. Strato – low clouds

34. Stratus
•Clouds formed at
medium or low
elevation; spread out
layer upon layer
covering a large area
•As stratus clouds
thicken, precipitation
usually occurs over
that area.

35. Cumulus
· Clouds formed at
medium or low elevation.
· Cumulus clouds are
puffy with flat bottoms.
· When cumulus clouds
are white they often signal
fair weather, but when
they are darker, they may
signal rain or
thunderstorms.

36. Cirrus
•Clouds formed at high elevations; wispy clouds usually
consisting of ice crystals that signal fair weather or may also
signal an approaching warm front.

37. Nimbus
· clouds are dark and so full of water that sunlight can’t
penetrate them

41. • Rain & Drizzle- most
common type of
precipitation.
• Freezing Rain- drizzle from
stratus clouds.
• Freezing Rain- raindrops
freeze when they hit the
ground.
• Sleet- raindrops that freeze
before they hit the ground.

42. •snow- as ice grows and
merges into clouds they
form snowflakes.
•hail- is the largest type
of precipitation.
• Lumps or balls of ice
that fall from
cumulonimbus clouds in
warm weather.

44. What is Weather?
• State of the atmosphere at a specific time and place
• Includes such conditions as air pressure, wind,
temperature, and moisture in the air
• Temperature is a measure of air molecule movement
• Sun’s energy causes air molecules to move
rapidly; temperatures are high and it feels warm
• When less of the Sun’s energy reaches air
molecules, they move less rapidly and it feels cold

45. • The average weather conditions over an extended
period of time.
• Weather may change from day to day or week to
week, but the climate of a location doest not change
so much.
• It describes the averages, totals and the extremes for
weather factors over long periods of time.
What is CLIMATE?

46. ELEMENTS of CLIMATE
TEMPERATURE & PRECIPITATION – the most important elements
of climate
Factors that determine that the Temperature and Climate :
1.LATITUDE
2.ELEVATTION
3.PREVAILING WINDS
4.BODIES OF WATER
5.MOUNTAIN RANGES

47. Anemometer- A tool used to measure
wind speed in miles per hour.
Wind vane
· A tool used to measure wind direction.
· Sometimes referred to as a
wind-weather vane or a wind sock.
· Wind direction is described by the
direction from which the wind is blowing.
Thermometer - A tool used to measure air
temperature in degrees Fahrenheit or
Celsius.

48. Sling Psychrometer-
•A two-thermometer
instrument also referred to
as a wet-dry bulb used to
measure relative humidity
(the amount of water
vapor in the air).
• Temperatures readings
are converted using a
relative humidity table.
Weather Instruments Video 1 15:01
Weather Instruments Video 2 19:41

49. Barometer- A tool used to
measure air pressure in
inches of mercury or
millibars (mb).
Rain gauge- A tool used for
measuring the amount of
precipitation in inches or
centimeters.

51. MENU

52. Reading a weather map
• ISOBAR=
connects areas
of equal
pressure.
• “BAR” comes
from
BARometric
pressure

53. Reading a weather map...
• Isotherm:
Connects areas
of equal
temperature;
“therm” means
temperature

54. Satellites
· Satellite images are used for seeing cloud
patterns and movements.
· For example, hurricane clouds and movement
can be observed using satellite images.
Radar
· Radar images can be used to detect cloud cover,
rainfall or storm location, intensity, and movement,
as well as the potential for severe weather (for
example, hurricanes or tornadoes).

55. Severe Weather
• Thunderstorms occur inside warm, moist
air masses and at fronts
• Warm, moist air is forced rapidly
upward, where it cools and condenses
• Strong updrafts of warm air and
sinking, rain-cooled air cause strong
winds

56. Lightning
• Movement of air inside a storm cloud causes
parts of the cloud to become oppositely
charged
• Current flows between the regions of
opposite electrical charge, forming a lightning
bolt
• Thunder – lightning superheats the air,
causing it to expand rapidly and then
contract, forming sound waves

57. Tornado
• Violent, whirling wind that moves in a narrow path
over land

58. Hurricane
• Large, swirling,
low-pressure
system that
forms over
tropical oceans
• Heat energy
from moist air is
converted to
wind that can
reach speeds of
250 km/h

59. Blizzard
• A winter storm with strong winds, cold temperatures,
and low visibility, that lasts more than three hours