1. Pressure Changes with Altitude
State the relationship between height (altitude) and pressure
Pressure reduces in half for each ______ km 5

2. 1% of the atmosphere
10% of atmosphere

4. Air Pressure Is Proportional to Density (density is how “packed” the molecules are per unit area)
At HIGH altitudes, the air is “thin”,
Pressure is less
At LOW altitudes, near the surface, there are more air molecules, so pressure is greater.

5. Factors that Affect Air Pressure
Density (altitude or elevation)
Temperature
Humidity (water vapor))
Weatherbug graph activity

7. Pressure Changes with Temperature
Warm air molecules have a lot of energy, are widely spaced apart – less dense, and exert less, LOW pressure.
Cold air contains slow moving molecules that are packed closely together (very dense) and exert HIGH pressure.

8. Air Pressure and Aviation
Altimeter: measures altitude by detecting change in air pressure

9. Temperatures vary due to UNequal heating of earth’s surface
Earth’s seasonal orbit around the Sun
Thickness of Earth’s atmosphere
Angle of the sun
23.5 degree tilt on axis

10. Temperature changes with Humidity (water vapor in the air)
Increase in water vapor (humidity) causes…
Air: N2 _____ and O2 _______
14 x x 2 = 60
Water vapor: H2O
2 Hydrogen ____ Oxygen ______
1 x = 18
air to be LESS dense = less, LOW pressure

11. Relative Humidity and air Pressure

12. Upper atmosphere winds (Jet Stream)

13. Upper Air-flow patterns cause Surface High and Low pressure
WGN explains

14. Convergence and Divergence
Air converges, piles-up and
is forced upward.
More air in a taller column
Causes vertical clouds and precipitation
Cold air sinks, and is forced to spread-out at the surface.
No clouds form – clear, fair weather

15. http://darktimeschronicle. wordpress

17. Cyclone
Anticyclone

18. What direction is this cyclone rotating?

19. in the Northern and Southern Hemispheres
Cyclonic Circulation
in the Northern and Southern Hemispheres