Arizona STEM

Acceleration Project

Weather Essentials for Aviators

Weather Essentials for Aviators

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A 9th grade STEM lesson

Sean Mark

1/30/24

Notes for Teachers

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• After becoming familiar with the factors that affect lift from the previous Flight Basics lesson and going over key weather concepts from this lesson, students will be expected to make a device to demonstrate low levels of wind speed. They will be guided through creating a stand, a balancing arm, and a uniform airfoil. Once these are completed, experiment using changes in weight to determine a scale and measuring device for wind speed.

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List of Materials:

• scissors
• glue
• soda cans
• clothes pins
• masking tape
• toothpicks
• paper clips
• straws
• 8” x 11” paper
• manila file folders

AZ Science Standards

Essential HS.P3U1.6

Collect, analyze, and interpret data regarding the change in motion of an object or system in one dimension, to construct an explanation using Newton’s Laws.

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Essential HS.P3U2.7

Use mathematics and computational thinking to explain how Newton’s laws are used in engineering and technologies to create products to serve human ends.

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Essential HS.P4U3.9

Engage in argument from evidence regarding the ethical, social, economic, and/or political benefits and liabilities of energy usage and transfer.

Plus HS+Phy.P4U2.7

Design, evaluate, and refine a device that works within given constraints to transfer energy within a system.

Essential HS.E1U1.11

Analyze and interpret data to determine how energy from the Sun affects weather patterns and climate.

Essential HS.E1U1.12

Develop and use models of the Earth that explains the role of energy and matter in Earth’s constantly changing internal and external systems (geosphere, hydrosphere, atmosphere, biosphere).

National Science Standards

Content Standard B: Physical Science

• Motions and forces

Content Standard E: Science and Technology

• Abilities of technological design

Content Standard F: Science in Personal and Social Perspectives

• Science and technology in society

Unifying Concepts and Processes

• Evidence, models, and explanation • Constancy, change, and measurement

Objectives:

LEARNING OUTCOMES – Upon completion of this lesson, the students should be able to:

• Describe the composition of the atmosphere.

• Describe how the Sun heats the Earth.

• Explain the various theories of circulation.

• Describe global wind patterns.

• Describe the condensation process.

• Define what precipitation is and give some examples.

• Define an air mass and identify air mass characteristics.

• Define a front and describe the types of fronts.

• Identify the stages of a thunderstorm.

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Agenda (60 minutes)

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What weather conditions affect flight?

Key Weather Concepts:

• atmospheric circulation
• global wind patterns
• humidity, dew point, moisture, systems
• air masses and fronts

Built-In Assessments

Wind Gauge Activity

Intro/Driving Question/Opening

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Ask students how weather elements such as wind, temperature, and pressure affect a pilot and his airplane. These and other weather elements affect aircraft in three ways (according to the Federal Aviation Administration or FAA): reducing visibility, creating turbulence, and reducing aircraft performance. Ask students to share any experiences, as an airplane passenger (commercial or other), that made the flight uncomfortable. Such conditions as turbulence or bumpiness, ear problems, unexpected bad weather, and hard landings can be discussed as having a weather connection.

Weather

The atmosphere

The Atmosphere

• Most “weather” occurs in the troposphere
• Sometimes stratosphere
• Tropopause is categorized by the ozone layer (or 36,089 MSL standard)
• Temperature inversion
• Temperature increases as you climb
• Temperature goes back to decreasing in the stratosphere
• Ozone (O3) is not good for you
• Most planes stay in the troposphere, sometimes tropopause (with ozone scrubber)
• Maybe even the stratosphere

Composition of the Atmosphere

• Standard at sea level
• 15 C (59F) and 29.92 inHg (1013.25mb) at standard sea level
• Air is 78% nitrogen, 21% Oxygen, 1% other
• Other: Carbon dioxide, argon, etc…
• Composition of air is ALWAYS the same regardless of altitude
• Air is still 21% oxygen at 35,000ft
• Air is less dense at high altitude
• i.e. less molecules per given volume

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Atmospheric Circulation

• Weather is caused by uneven heating
• Always trying to reach equilibrium
• Water heats slower than the ground
• Asphalt heats and cools faster than grass
• Heat likes traveling from hot to cold
• Like osmosis, but with energy
• High to low concentration
• Increasing energy in a closed system raises pressure
• Pressure = force per area (PSI)
• Pressure systems like going high to low

Atmospheric Circulation

• Heat and density
• High heat = low density
• Molecules with higher energy move more
• More movement requires more space
• Low density = rising air

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Quick quiz

Global Wind Patterns

• Coriolis force
• In the upper hemisphere, wind shifts to the right in the direction of motion
• Due to the earth’s rotation
• PROOF THAT THE EARTH IS NOT FLAT
• Pressure systems move high to low
• High pressure – out, clockwise, down
• Low pressure – in, counterclockwise, up

Global Wind Patterns

• Coriolis causes 3 circulation cells in each hemisphere
• Hadley, Ferrell, and Polar
• Low pressure over the equator
• The boundaries between each cell causes jet streams
• Polar cell retreats north in summer

Global Wind Patterns

• Pressure gradient force
• Differential pressure causes wind
• High to low pressure
• Isobars = areas of same pressure
• Closer isobars = stronger winds
• Further isobars = calmer winds
• Friction
• Winds at the surface are not as strong as winds at high alt. due to friction

Global Wind Patterns

• Coriolis force has greater effect at high alt
• Pressure gradient force has higher influence at low alt
• Friction has higher influence at low alt
• Winds are strong at high alt because low friction

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Local Winds

• Sea breeze
• During warm sunny day
• Air over land heats up and rises
• Air over water cools and sinks
• Air flows from water to land causing a sea breeze
• Land breeze
• At night
• Water warmer than land at night
• Air rises over water
• Air sinks over land
• Wind flows from land to water

Local Wind Patterns

• Valley breeze
• Air is warmed up by the ground and rises up the slope
• Air rises and over the mountain
• Sinking air on other side
• Mountain breeze
• The ground cools faster than the air above the mountain
• Air sinks
• Causes wind down the mountain

Quick Quiz 2

Humidity

• Humidity is water in the air
• Relative humidity: the amount of water air is holding relative to the amount it can hold
• Air can hold more water at higher temps
• Hot air is less dense
• Less dense = more space for water
• Cool air is denser = less room for water
• 60% humidity has more water if it is at 40C than 20C

Dew Point

• What happens when relative humidity reaches 100%?
• 100% humidity = saturation
• Saturation = air cannot hold more water
• Visible moisture forms at 100% humidity
• Dew point = the temperature at which air becomes saturated
• When you cool air, you are essentially squeezing the water out
• A cloud forms when moist air rises up to the dew point

Dew Point and Visible Moisture

• When the surface temperature is within 2C of the dewpoint, expect fog
• Fog is a low altitude cloud
• if the dew point is below freezing, frost will form if the temperature reaches the dew point
• Frost requires the surface to be below freezing

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Atmospheric Stability

• Stability = the ability to resist vertical motion
• Air rising then returning back to its original altitude is STABLE
• Air that continuously rises is unstable
• Lapse rate
• Standard lapse rate = 2C per 1000ft
• Dry adiabatic lapse rate = 3C per 1000ft
• Moist adiabatic lapse rate = 1.1-2.5C per 1000ft
• Moist adiabatic lapse rate is less than dry because when water evaporates, it absorbs energy so the surrounding air heats up slower

Lapse Rate and Stability

• If the lapse rate is less than standard, air is stable
• If lapse rate is normal, air is neutral
• If lapse rate is greater than standard, air is unstable
• Flying in stable air
• Less visibility, smooth, maybe drizzle but consistent precip
• Flying in unstable air
• Bumpy, showery precip, better visibility

Visible Moisture

• Clouds and fog forms when air becomes saturated
• Cumulus and stratus clouds
• Cumulus are big and fluffy
• Stratus do not have vertical development
• Stratus forms in stable air
• Can fly through (flying IFR)
• Can cause continuous drizzle precip
• Stable
• Not really hazardous

Visible Moisture

• Cumulus clouds
• Unstable
• Vertical development
• Has up and down drafts
• Showery precip
• Dangerous to fly in

Thunderstorms

• 3 stages
• Cumulus
• Big towering cloud rising
• updrafts
• Mature
• ‘anvil’ forms
• Start of precipitation
• Start of lightning
• Up and down drafts
• Dissipating
• Downdrafts

Ingredients of Thunderstorms

• Unstable air
• Air with vertical development
• Moist air
• Initial rising action
• Example: Florida and Texas coast

Quick Quiz 3

Air Masses

• Air mass = a body of air that shares the same temperature and pressure characteristics
• Weather is caused by air masses “going to war” with each other
• 4 main air masses in the upper hemisphere
• Cold
• Warm
• Occluded
• Stationary

Cold Front

• Moves the fastest (25-30 mph up to 60)
• Characterized by:
• Showery precip
• Good visibility after passage
• Cumulus clouds
• Unstable
• Showers and cumulus clouds would form while front passes
• Visibility will clear up after passage
• Calm after the storm

Warm Front

• Not fast moving
• Stable air
• Stagnant air
• Bad visibility
• Stratiform clouds
• Drizzly continuous precipitation

Stationary Front

• “a front detached from the jet streams”
• A mix of warm and cold front
• Continuous drizzle
• not really stable, but not really unstable
• Gloomy weather that sticks around
• Can stick around for up to a week

Occluded Front

• A warm front sandwiched between two cold fronts
• 2 types
• Cold occluded
• Warm occluded
• Cold occluded
• The cool air behind is cooler than the cold mass in front
• More severe weather most of the time
• Steep gradient
• Stormy weather

Occluded

• Warm occluded
• Air behind is not as cold as the air in front
• Still stormy not good weather
• Typically, better than cold occluded
• EXCEPT if the air is unstable
• Unstable warm occluded is WORSE than cold occluded

Final quiz

Hands-On Activity: Wind Gauge Experiment

After constructing a simple wing device (see #7 in Additional Resources), Using a blow dryer on low setting, determine the mass that your Airfoil will lift. You do this by adding weight to the Airfoil side pan until you have an easy leveling process.

• Add one more mass beyond the level position. This confirms that you had the maximum weight lift for that airspeed.
• Record the maximum mass in grams that your foil could lift.
• Increase the dryer speed to the middle level and continue collecting your data as you did before. Record.
• Finally, increase the dryer to its top speed and collect your data. Record.
• Graph these three points.

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The Analysis

1. Based on your observations and your data, what do you think will happen as you increase the mass and not the airspeed?�
2. Based on your observations and your data, what do you think will happen as you increase the airspeed and not the mass?�
3. What do you predict will happen if you blow across the Trailing Edge of the wing section?�
4. List other wing shapes that you think might work better and tell how you would test your predictions.

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• data

Data Table:

Assessment

Quick Quizzes (throughout lesson):

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What are the names of the layers of the atmosphere?

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Why does heat rise and cool air sink?

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What direction does the Coriolis Force act in the upper hemisphere?

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What is pressure gradient force?

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Where do jet streams occur?

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How do clouds/fog form?

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What are the stages of a thunderstorm?

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What is stable air?

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Final Check for Understanding:

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What is an air mass?

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What are the characteristics of each air mass?

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What is the composition of the atmosphere?

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Why is dry adiabatic lapse rate greater than moist adiabatic lapse rate?

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What does a cumulus cloud look like and what are its properties?

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Extension/Enrichment

1. Additional activities on Atmosphere and Weather provided by National Earth Science Teachers Association’s “Windows to the Universe” website at http://www.windows2universe.org/php/teacher_resources/activity.php#3.

2. Information and quizzes about the atmosphere at: http://www.geography4kids.com/files/atm_intro.html.

3. View incredible photos of earth, earth’s atmosphere and weather at http://science.nationalgeographic.com/science/earth/earths-atmosphere.

4. Video that shows an experiment that forms a cloud in a bottle at http://vimeo.com/13582249. Clouds form when water vapor cools down. Warm moist air in the atmosphere rises and the pressure reduces as it goes higher. As pressure reduces it gets colder. Eventually the water vapor cools enough to form clouds.

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Additional Resources

Additional Resources (cont.)

5. A website with information and a video demonstrating the Coriolis force by rolling a ball across a merry-go-round is at http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/fw/crls.rxml.

6. “The Top Ten Practical Considerations for Mountain Flying” from AV Web (World’s Premier Independent Aviation News Resource) is at http://www.avweb.com/news/airman/184273-1.html.

7. Wind gauge activity at http://www.grc.nasa.gov/WWW/k-12/problems/Lorri/wind_gauge_act.htm#RETURN.

8. More about temperature scales and math from PBS at http://www.pbs.org/teachers/mathline/concepts/weather/activity1.shtm

9. The types of clouds are explored in this interactive and visually stimulating activity. Low, middle, and high level clouds are presented by NASA and S'COOL (Student Cloud Observations Online) giving a complete guide to cloud identification: http://asd-www.larc.nasa.gov/SCOOL/tutorial/clouds/cloudtypes.swf.

10. Online interactive severe weather games from the Weather Channel at http://www.theweatherchannelkids.com/flash/games/severe-weather-challenge/ .

Differentiation

1. The quick quizzes can be done in a variety of ways to meet your students’ needs. Small group, whole class, vary the ways students are answering, etc.

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2. The hands-on activity can be in carefully chosen groups to ensure that all students have access to the activity.

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Remediation Ideas