The Atmosphere

1
The Atmosphere
2

• Warm-Up Questions
• CPS Questions 1-2

3
Chapter Overview

• Lesson 1 The Atmosphere
• Lesson 2 Weather Elements
• Lesson 3 Aviation Weather
• Lesson 4 Weather Forecasting
• Lesson 5 The Effects of Weather on
• Aircraft

4
Lesson Overview

• The atmospheres regions
• The roles of water and particulate matter in the
  atmosphere
• The primary causes of atmospheric motion
• The types of clouds
• How the atmospheric layers impact flight

5
Quick Write

• What are some of the advantages to
• using low-tech equipment? What are some of the
  disadvantages?
• (Note to teacher Use Pick a Student button in
  CPS)

Courtesy of NOAA
6
The Atmospheres Regions

• Extends more than 350 miles from Earths surface
• Life on earth is supported by atmosphere, solar
  energy, and magnetic fields
• Nitrogen 78 of the atmospheres gases, oxygen
  21 and argon, carbon dioxide, and traces of
  other gases 1

Reproduced from US Department of
Transportation/Federal Aviation Administration
7
Five Distinct Layers Troposphere

• Lowest layer reaches from sea level to about
  four to nine miles
• Dense stretch of atmosphere where most weather
  takes place
• Boundary layer called tropopause traps moisture
  and weather

8
Stratosphere

• Above the troposphere and extends about 30 miles
• Drier and less dense than troposphere
• Temperature begins to rise again to about 26.6
• Stratopause boundary layer separates it from next
  layer

Reproduced from US Department of
Transportation/Federal Aviation Administration
9
Mesosphere

• Above the stratosphere to about 53 miles
• Temperatures dip as low as -135.4 F
• Chemicals exist in an excited state, they absorb
  energy from sun
• The boundary layer at the top is the mesopause

Courtesy of NASA
10
Thermosphere Exosphere

• Thermosphere starts above the mesosphere and
  extends about 350 miles
• Temperature goes as high as 3,140.6 F
• Chemical reactions occur faster here than on
  Earths surface
• Boundary layer is the thermopause
• ExosphereStretches to the edges of space at
  around 6,200 miles

11
Activity 1 Atmospheric Regions

•  
• Match the atmospheric region to its appropriate
  place on the illustration provided
• Add additional features about each region

12
Roles of Water in the Atmosphere

• Evaporationtransformation of liquid to gaseous
  state
• Sublimationsolid changes to gas without going
  through liquid state

13
Roles of Water in the Atmosphere, cont.

• Condensationchange of water from gaswater
  vaporto a liquid
• Depositiongas changes to solid without going
  through liquid state
• Melting
• Freezing

Courtesy of NASA
14
Evaporation

• Oceans are source of 86 of
• evaporation
• Evaporation requires heat
• Air loses heat when water changes to vapor
• Condensing water forms clouds
• Water in clouds can fall as rain, snow, some
  other form
• Moisture falling seeps into soil and groundwater
  through infiltration

Courtesy of NOAA/Historic NWS Collection
15
Sublimation

• Sublimation takes place in colder climates
• Temperatures can be too cold on a mountaintop to
  melt snow and ice to liquid
• Intense sunlight with strong winds can transform
  snow and ice into water vapor

Courtesy of NASA/Goddard/Sarah DeWitt
16
Humidity and Relative Humidity

•  Humidity - amount of water in atmosphere at a
  given time
• Relative humidity - amount of moisture in air
  compared amount of moisture the air could hold at
  that temperature

17
Dew Point

• Temperature at which air can hold no more
  moisture
• Air becomes saturated, water condenses as fog,
  dew, frost, clouds, rain, hail, or snow

Courtesy of NASA/Ben Smegelsky
18
Particulate Matter

• Water vapor and cloud droplets make up a cloud
• Water vapor clings to particulate matter to
  condense into cloud droplets
• Bits of particulate matter act as nucleusor
  coreof the raindrop

Courtesy of Sean Waugh NOAA/NSSL
19

• Learning Check Questions
•  
• CPS Questions 3-4

20
The Primary Causes of Atmospheric Motion

• Heat causes air to circulate around Earths
  surface
• Rising warm air and heavy, sinking cool air
  results in atmospheres circular motion
• Tilted axis affects atmospheric circulation

Modified from US Department of Transportation/Fede
ral Aviation Administration.
21
Coriolis Force

• How Earths rotation affects the motion of air
• Deflects air to the right in Northern Hemisphere
  and left in Southern Hemisphere
• Breaks up flow of air into three cells at
  different latitudes in each hemisphere

Reproduced from US Department of
Transportation/Federal Aviation Administration
22
Activity 2 Atmospheric Motion

• Read the information in Part 1 and Part 2, and
  answer the questions
• Conduct the experiment outlined in Part 3

23
Types of CloudsLow Clouds

• Near Earths surface up to about 6,500 feet
• Low clouds are stratus, stratocumulus,
  nimbostratus, and fog
• Can make visibility difficult, pilots rely on
  instruments to fly through them

Courtesy of NOAA Photo Library, National Weather
Service (NWS) Collection. Photographer Ralph F.
Kresge.
24
Middle Clouds

• Around 6,500 feet and reach up to about 20,000
  feet
• Made of water, ice crystals, and supercooled
  water droplets
• Middle clouds are altostratus and altocumulus

Courtesy of NOAA Photo Library, National Weather
Service (NWS) Collection. Photographer Ralph F.
Kresge.
25
High Clouds

• Above 20,000 feet, usually form only in stable
  air
• Contain ice crystals, pose no real risk of
  turbulence or icing
• High clouds are cirrus, cirrostratus, and
  cirrocumulus

Courtesy of NOAA Photo Library, National Weather
Service (NWS) Collection, Photographer Captain
Albert E. Theberge Jr.,
26
Cumulus Clouds

• Lots of vertical development
• Flat base that forms in low or middle cloud
  regions
• Cumulus, particularly cumulonimbus clouds, can
  mean turbulent weather ahead
• Can be most dangerous cloud to encounter in
  flight

Courtesy of NOAA Photo Library
27
Activity 3 All About Clouds

• Name and describe some of the features of the
  clouds pictured

28

• Learning Check Questions
•  
• CPS Questions 5-6

29
Atmospheric Layers Impact FlightDensity

• Lower altitudes, density of air increases, higher
  altitudes, density decreases
• Air that is less dense engines and propellers
  are less efficient, take in less air

Courtesy of NASA
30
Pressure

• Increasing altitude affects atmospheric pressure
• Means to measure pressure is standard conditions
• Atmospheres weight at 18,000 feet is half what
  it is at sea level
• Regulations require cabin altitude of 8,000 feet

Reproduced from US Department of
Transportation/Federal Aviation Administration
31
Temperature

• Temperatures drop dramatically with altitude
  drop continues until around 36,000 feet
• Airplanes have systems that regulate temperature
  and heat cabins

Reproduced from US Department of
Transportation/Federal Aviation Administration
32

• Learning Check Questions
•  
• CPS Questions 7-8

33
Activity 4 Atmospheric Factors

• Write a short paper about how aircraft today
  address the effects of air density, pressure,
  and/or temperature
• Conduct and investigate research using the
  sources identified

34
Summary

• The atmospheres regions
• The roles of water and particulate matter in the
  atmosphere
• The primary causes of atmospheric motion
• The types of clouds
• How the atmospheric layers impact flight

35

• Review Questions
•  
• CPS Questions 9-10

36
Next.

• Done the atmosphere
• Next weather elements

Courtesy of Robert Schwemmer/NOAA/NOS/CINMS