The document discusses the composition, structure, and properties of Earth's atmosphere. It describes how the atmosphere forms the basis of weather and climate. Weather is defined as short-term atmospheric conditions averaged over days, while climate refers to averaged conditions over decades. The atmosphere is composed primarily of nitrogen, oxygen, and argon. It also contains greenhouse gases like carbon dioxide and water vapor that trap heat and influence Earth's temperature. Solar energy interacts with the atmosphere through reflection, absorption, and the greenhouse effect. Uneven heating of the atmosphere due to Earth's tilted axis drives global wind patterns and local breezes that influence weather conditions around the world.

1. The Atmosphere

2. BIG Idea:
• The composition, structure, and
properties of Earth’s
atmosphere form the basis of
Earth’s weather and climate.

3. Who studies atmospheric
conditions?
•Meteorologists…that’s who!

4. • How would you describe the
difference between
WEATHER and CLIMATE?

6. I. Characteristics
of the Atmosphere
• Weather = day-to-day changes
in atmospheric conditions.
•These conditions include:
•Temperature
•Air movements
•Moisture content

7. • Climate = general weather
conditions averaged over
many (about 30) years

8. A. Composition of the
Atmosphere
• 78% Nitrogen
• 21% Oxygen
• 0.9% Argon
• 0.1% Other

9. • Ozone – protects us
from harmful UV
(ultraviolet) rays
Damaged by CFCs
(poisons in ACs
and refrigerators)
Ozzy Ozone

10. B. Properties of the
Atmosphere
1)Temperature
2)Air Pressure
3)Humidity

11. 1. Temperature
• measure of the
average kinetic
energy of particles in a material
• more energy = moving faster =
higher temperature
• measured with a thermometer

12. 2. Atmospheric (Air)
Pressure
• the ratio of the force of the
air to the area of the surface
on which it presses
• the weight of the atmosphere
pressing down on Earth’s
surface

13. BAROMETER
• an instrument that measures
atmospheric pressure

14. a. Mercurial Barometer

15. b. Aneroid Barometer
• Aneroid = ‘without liquid’

16. 3. Humidity
• the amount of water vapor in
the atmosphere at a given
location on Earth’s surface

17. C. Layers of the
Atmosphere
- Based on temperature
differences, scientists
identify four layers of
Earth’s atmosphere
- Each layer is separated by a
“pause”

20. 1. Troposphere: all weather
occurs here
• Layer closest to Earth’s surface

21. 2. Stratosphere: where most
of the ozone is

22. 3. Mesosphere: coldest layer
(-90°C )
4. Thermosphere: hottest
layer (over 2000°C); nitrogen
and oxygen atoms absorb
solar energy

24. II. Solar Energy
A. Radiation: all
forms of energy
that travel
through space
as waves

26. What happens to solar energy
that reaches Earth’s surface?

27. 1.reflected (sent in a new
direction), or
2.absorbed

29. • Why does the
inside of a
closed parked
car heat up,
while the
windows stay
cool?

32. B. Greenhouse Effect:
atmosphere traps (long) infrared
rays
• The Sun’s energy
is trapped
inside.

34. • What are the ‘greenhouse
gases’ that trap heat within
our atmosphere?

35. 1. Water vapor
2. Carbon dioxide
 produced by humans
 burning of fossil fuels (oil,
gas, coal)

38. C. Heat Energy Transfer

39. 1. Convection: transfer of heat
energy in gases or liquids due
to density differences.

40. 2. Conduction: transfer of heat
energy through matter from
particle to particle;
most effective in
solids.

41. 3. Radiation: waves that directly
transport energy through
space; brings
HEAT to our
planet.

42. III. Winds
• Created by uneven heat
distribution at Earth’s surface
–The amount of energy
reaching any given point on
Earth’s surface is controlled
by the angle of sunlight
striking the surface

43. • What causes the amount
of energy to vary?

45. • Our tilt!
• Where on Earth will you
receive more of the sun’s
energy per unit area?
• Where will you receive
less?

48. • The Coriolis Effect: Earth’s rotation
causes winds to deflect (curve) to
the right in the Northern
Hemisphere and to the left in the
Southern
Hemisphere.
• Same with water

50. A. Global Winds
Winds are named according to the
direction FROM which they flow!
1. Trade Winds (Tropical Easterlies) –
winds in both hemispheres
flowing towards the equator
 between 30° (N and S) and 0°
latitude

51. a. Doldrums – weak and
unpredictable air mix, 5° N and S
of the equator
*winds CONVERGE here to form an
area of LOW pressure
b. Horse Latitudes – very weak air
movement 30°- 35° N and S

52. 2. Westerlies – between 30° and 60°
N and S.
3. Polar Easterlies – weak winds at
60° N and S that flow away from
the poles.

54. 4. Jet Stream – bands of high-
speed high-altitude westerly
winds.

55. B. Local Winds / Breezes

56. 1. Sea Breeze – in the daytime,
winds from cooler water replace
warm rising land air

57. 2. Land Breeze – at night, winds
from cooler land replace warm air
over the water

58. 3. Valley Breeze – in the day
warm air rises UP the valley

59. 4. Mountain Breeze – at night, cool
air sinks DOWN the mountain

60. What causes weather?
• uneven heating by the
Sun due to Earth’s axis
tilt
• energy transfer between
Earth’s surface and the
atmosphere