Upcoming SlideShare
×

# Weather Theory Part I (Group C)

• 399 views

Weather Theory Part I (Group C)

Weather Theory Part I (Group C)

More in: Education
• Comment goes here.
Are you sure you want to
Be the first to comment
Be the first to like this

Total Views
399
On Slideshare
0
From Embeds
0
Number of Embeds
0

Shares
7
0
Likes
0

No embeds

### Report content

No notes for slide

### Transcript

• 1. Weather TheoryPart I. The Atmosphere
Group C: Second Year
• 2. Essential Questions
?
?
What is the atmosphere and what is its lowestlevel?
How does atmospheric circulation work? What factors manipulate this circulation?
What is the Coriolis Effect?
What is atmospheric pressure? What factors effectit?
What are standard atmosphere conditions?
How does altitude relate to aircraft performance? The human body?
• 3. Important Terms
Density – mass of something per volume
Pressure – force of something per volume
Coriolis Effect – the modification of air circulation patterns due to Earth’s rotation
• 4. Section I. Atmosphere
Body of air that surrounds the Earth
Always striving to achieve equilibrium – always in motion due to unequal heating of Earth’s surface
High/low pressure
Supports all forms of life on Earth
• 5. Composition of the Atmosphere
78% nitrogen, 21% oxygen, 1% other
Water demo
Troposphere
Surface to 20,000 feet MSL
Possesses most weather activity
-2°C per 1,000 feet of altitude
-1 inch of Hg per 1,000 feet of altitude
Tropopause traps most weather inside troposphere
• 6. Atmospheric Circulation
Warm air is thin (less dense) and has lower pressure, therefore it rises
Cool air is thick (more dense) and has higher pressure, therefore it sinks
Water/oil demo
Unequal heating is due to Earth’s curved surface and that it rotates on a tilted axis
Air is heated at equator, rises to pole, cools, and sinks back to equator – process repeats itself
• 7. Balloon Activity 1
Step 1. Put the balloon into the top of the bottle without dropping it. Seal the top of the bottle with the lip of the balloon.
Step 2. Cover the hole and try to inflate the balloon.
Step 3. Uncover the hole and try to inflate the balloon.
What’s the difference? What happened during each trial?
• 8. Atmospheric Pressure
The force exerted by the weight of air molecules
Atmospheric circulation also affects atmospheric pressure
A column of air would weigh more at sea level than at 18,000 feet
Pressure can be affected by altitude, temperature, and density
Pressure conditions affect aircraft performance, such as takeoffs, rates of climb, and landings
Generally, most high pressure exists over polar regions and most low pressure exists over equatorial regions because of difference in temperature
• 9. Balloon Activity 2
Step 1. Blow up your balloon.
Based on the previous slide, what can you conclude about the differences in air pressure?
• 10.
• 11. Section II. Coriolis Effect
Pattern of air circulation is modified by rotation of Earth, called coriolis effect
Northern Hemisphere:
Air deflected to right
Air rotates clockwise around high pressure areas
Air rotates counterclockwise around low pressure areas
Southern Hemisphere:
Air deflected to left
Air rotates counterclockwise around high pressure areas
Air rotates clockwise around low pressure areas
• 12. Section II. Coriolis Effect
Coriolis deflects more closer to the equator and less closer to the poles
• 13. Section III. Measurement of Atmosphere Pressure
Measured in inches of mercury (Hg) by a barometer
Atmospheric pressure also called barometric pressure
Pressure of atmosphere pushes on a column of Hg that is advanced up a glass tube on a scale
ISA – International Standard Atmosphere
Standard pressure = 29.92’’ Hg (at sea level)
Standard temperature = 15°C (59°F)
• 14. Section III. Measurement of Atmosphere Pressure
Mercurial Barometer
• 15. Section IV. Altitude and Atmospheric Pressure
Atmospheric pressure decreases as altitude increases
Pressure decreases by 1’’ Hg per every 1,000 feet
Pressure decrease = density decrease
Air density is changed by temperature which changes pressure
• 16. Section V. Altitude and Flight
Takeoff/landing distances and climb rates increase at higher altitudes due to decreased atmospheric pressure
More speed is required to takeoff if air is thinner (less of it exists in the same area)
Propellers are also less efficient at higher altitudes – reduced rates of climb
• 17.
• 18. Section VI. Altitude and the Human Body
Hypoxia
Less oxygen exists at higher altitudes, even though concentration stays constant
Hypoxia generally begins around 10,000 feet but can begin as low as 5,000 feet
Cabin oxygen systems allow some planes to fly at very high altitudes
• 19. Water Activity
• 20. O
6
33%
N
12
67%
N
6
67%
O
3
33%
:Gas:
:Quantity:
:Concentration:
N
O
N
O
Box A
Box B
Quantity vs. Concentration
• 21. Quiz Time!!!
How does a barometer work?
Atmospheric pressure exerts force on mercury which advances up a glass tube.
• 22. Quiz Time!!!
Explain the difference between quantity and concentration.
Quantity is the actual total amount of something within a given area, whereas concentration is the amount of that something in relation to the whole.
• 23. Quiz Time!!!
How much does pressure decrease as altitude increases?
1’’ Hg per 1,000 feet of altitude
• 24. Quiz Time!!!
What are standard atmosphere conditions?
29.92’’ Hg
15°C (59°F)
• 25. Quiz Time!!!
Why is the atmosphere always in constant motion?
It strives to achieve equilibrium by replacing low pressure with high pressure until the pressures are equal.
• 26. Quiz Time!!!
What happens to warm air? What happens to cool air?
Warm air: less dense/thinner, rises
Cool air: more dense/thicker, sinks
• 27. Quiz Time!!!
What is the composition of the atmosphere?
78% nitrogen
21% oxygen
1% other
• 28. Essential Questions
?
?
What is the atmosphere and what is the bottom-most level?
How does atmospheric circulation work? What factors manipulate this circulation?
What is the Coriolis Effect?
What is atmospheric pressure? What factors change it?
What are standard atmosphere conditions?
How does altitude relate to aircraft performance? The human body?
• 29. Questions?
www.centennialaviationclub.com
logan@centennialaviationclub.com