1. Atmospheric Pressure

2. What is pressure?
The amount of force per unit of area

3. What is atmospheric pressure?
The force caused by the weight of air
15 pounds per square inch (lbs/in2) Or
1 kilogram per square centimeter (kg/cm2)

4. How is air pressure exerted on us at the surface of the earth?
Like this
In ALL directions
Not like this

7. Which weighs more? Dry Air Moist Air O O H H O N N Oxygen (O2)
Atomic Mass = 32
Water
Atomic Mass = 18 N N
Nitrogen (N2)
Atomic Mass = 28

8. What affects the amount of air pressure exerted on the surface of the earth?
Temperature: temperature air pressure
Elevation: elevation air pressure
Moisture content: moisture air pressure
Density: density air pressure

9. Measuring Atmospheric Pressure
Barometer

10. Isobar
                                                                                                                                                                            
Lines on a weather map that connect locations with the same air pressure

11. Atmospheric Heating

12. Convection
The motion or movement of large groups of molecules based on their relative densities or temperatures. (Warm air rises-less dense- and cool air moves in to replace it.)

13. Conduction
Conduction is the direct transfer of energy through direct contact between atoms.

14. Radiation
The method by which the sun's energy reaches the earth. All objects radiate: hotter ones radiate more. Two objects at the same temperature, and the same size do not radiate the same amount of heat.

15. Describe heat transfer in the Earth
Radiant energy from the sun heats the surface of Earth
Through conduction Earth heats the air in contact with it;
Through convection the warm air rises and is replaced by cool air, the warm air cools and sinks back to the surface

16. How does a thermometer work?
The liquid inside expands when heated, rising up the tube
it contracts when cooled and gets lower