1. Air Pressure and Wind

2. Pressure, Volume, Temperature
If you increase pressure, what happens to Volume and Temperature?
If you increase temperature, what happens to Volume and Pressure?
Write a few sentences in your journal to explain two ways that pressure, temperature and volume are linked when talking about weather changes.

3. Air Pressure – “rules”
Air pressure is exerted in all directions – up, down, sideways.
The pressure balances in all directions equally.
refer to can crushing demo; hot air balloon image in note packet
Standard sea level measurement is millibars = inches of mercury

4. Air pressure and weather
Compare sea level readings to what our weather journals have indicated.
What weather should we expect to see when barometric pressure decreases?
What weather conditions would you predict when barometric pressure increases?
Those are the Low and high pressure systems referred to on weather forecasts
Where does temperature come into play then?

5. the steeper the difference which leads to more/ higher winds
How are the Pressure gradients related to wind? the closer the gradients ____________________.

6. How is temperature related to wind?

7. What is the Low pressure in the Atlantic ocean?

8. How do winds blow around Pressure systems?
Low pressure = “cyclone”, pressure decreases as you travel more toward the center – flow is counterclockwise
High pressure “anti-cyclone” – pressure increases as you travel toward the center – flow is clockwise
Rotation is due to change of pressure and Coriolis effect (more on this soon)
Right/ left hand demo

9. Sketch this in your journal

10. Wind - cause and result
The unequal heating of the earth’s surface creates differences in temperature, which leads to differences in pressure.
Air flows from high pressure to areas of low pressure (this is diffusion – it happens with all molecules and matter, it is what we saw in the convection lab)
Wind is the result of horizontals differences in air pressure.
Solar energy is the ultimate energy source for most wind!

11. 3-D high and low pressure meet
Sketch this

12. Summarize Please write 5 summary sentences, include the following:
how is wind “created”
What is the difference between high and low pressure systems in their motion
What does barometric tell us in a weather report
What kind of weather is associated with high and low pressure systems

14. Factors affecting Wind
1. pressure differences ( caused by? )
2. Coriolis effect ( caused by?)
3. Friction ( between air molecules and earth’s surface features)
Pressure differences – the greater the differences the greater the wind speed

15. Wind symbols

16. Measuring Air Pressure
A student of Galileo, invented a mercury Barometer – as air pressure in the tube increases, mercury rises in tube; as air pressure decreases, the column of mercury does also.
Our weather data measure Barometric pressure in inches, this relates back to the original measurement system.