The Atmosphere

Warm-Up Questions CPS Questions 1-2 Chapter 2, Lesson 1

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 Aircraft Chapter 2, Lesson 1

Lesson Overview  The atmosphere’s 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 Chapter 2, Lesson 1

Quick Write What are some of the advantages to using low-tech equipment? What are some of the disadvantages? using low-tech equipment? What are some of the disadvantages? (Note to teacher: Use “Pick a Student” button in CPS) Chapter 2, Lesson 1 Courtesy of NOAA

The Atmosphere’s Regions  Extends more than 350 miles from Earth’s surface  Life on earth is supported by atmosphere, solar energy, and magnetic fields  Nitrogen 78 % of the atmosphere’s gases, oxygen 21 %; and argon, carbon dioxide, and traces of other gases 1% Chapter 2, Lesson 1 Reproduced from US Department of Transportation/Federal Aviation Administration

Five Distinct Layers Troposphere 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 Chapter 2, Lesson 1

Stratosphere  Above the troposphere and extends about 30 miles  Drier and less dense than troposphere  Temperature begins to rise again to about 26.6 ⁰  Stratopause boundary layer separates it from next layer Chapter 2, Lesson 1 Reproduced from US Department of Transportation/Federal Aviation Administration

Mesosphere  Above the stratosphere to about 53 miles  Temperatures dip as low as ⁰ F  Chemicals exist in an excited state, they absorb energy from sun  The boundary layer at the top is the mesopause Chapter 2, Lesson 1 Courtesy of NASA

Thermosphere Thermosphere —Exosphere  Thermosphere starts above the mesosphere and extends about 350 miles  Temperature goes as high as 3,140.6 ⁰ F  Chemical reactions occur faster here than on Earth’s surface  Boundary layer is the thermopause  Exosphere—Stretches to the edges of space at around 6,200 miles Chapter 2, Lesson 1

Activity 1: Atmospheric Regions  Match the atmospheric region to its appropriate place on the illustration provided  Add additional features about each region Chapter 2, Lesson 1

Roles of Water in the Atmosphere  Evaporation—transformation of liquid to gaseous state  Sublimation—solid changes to gas without going through liquid state Chapter 2, Lesson 1

Roles of Water in the Atmosphere, cont.  Condensation—change of water from gas— water vapor—to a liquid  Deposition—gas changes to solid without going through liquid state  Melting  Freezing Chapter 2, Lesson 1 Courtesy of NASA

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 Chapter 2, Lesson 1 Courtesy of NOAA/Historic NWS Collection

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 Chapter 2, Lesson 1 Courtesy of NASA/Goddard/Sarah DeWitt

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 Chapter 2, Lesson 1

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 Chapter 2, Lesson 1 Courtesy of NASA/Ben Smegelsky

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 nucleus—or core—of the raindrop Chapter 2, Lesson 1 Courtesy of Sean Waugh NOAA/NSSL

Learning Check Questions CPS Questions 3-4 Chapter 2, Lesson 1

The Primary Causes of Atmospheric Motion  Heat causes air to circulate around Earth’s surface  Rising warm air and heavy, sinking cool air results in atmosphere’s circular motion  Tilted axis affects atmospheric circulation Chapter 2, Lesson 1 Modified from US Department of Transportation/Federal Aviation Administration.

Coriolis Force  How Earth’s 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 Chapter 2, Lesson 1 Reproduced from US Department of Transportation/Federal Aviation Administration

Activity 2: Atmospheric Motion  Read the information in Part 1 and Part 2, and answer the questions  Conduct the experiment outlined in Part 3 Chapter 2, Lesson 1

Types of Clouds—Low Clouds  Near Earth’s 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 Chapter 2, Lesson 1 Courtesy of NOAA Photo Library, National Weather Service (NWS) Collection. Photographer: Ralph F. Kresge.

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 Chapter 2, Lesson 1 Courtesy of NOAA Photo Library, National Weather Service (NWS) Collection. Photographer: Ralph F. Kresge.

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 Chapter 2, Lesson 1 Courtesy of NOAA Photo Library, National Weather Service (NWS) Collection, Photographer: Captain Albert E. Theberge Jr.,

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 Chapter 2, Lesson 1 Courtesy of NOAA Photo Library

Activity 3: All About Clouds  Name and describe some of the features of the clouds pictured Chapter 2, Lesson 1

Learning Check Questions CPS Questions 5-6

Atmospheric Layers Impact Flight—Density  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 Chapter 2, Lesson 1 Courtesy of NASA

Pressure  Increasing altitude affects atmospheric pressure  Means to measure pressure is standard conditions  Atmosphere’s weight at 18,000 feet is half what it is at sea level  Regulations require cabin altitude of 8,000 feet Chapter 2, Lesson 1 Reproduced from US Department of Transportation/Federal Aviation Administration

Temperature  Temperatures drop dramatically with altitude; drop continues until around 36,000 feet  Airplanes have systems that regulate temperature and heat cabins Chapter 2, Lesson 1 Reproduced from US Department of Transportation/Federal Aviation Administration

Chapter 2, Lesson 1 Learning Check Questions CPS Questions 7-8

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 Chapter 2, Lesson 1

Summary  The atmosphere’s 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

Chapter 2, Lesson 1 Review Questions CPS Questions 9-10

Next….  Done – the atmosphere  Next – weather elements Chapter 2, Lesson 1 Courtesy of Robert Schwemmer/NOAA/NOS/CINMS