1. Sunday Morning

2. Sunday Night

3. Monday Morning

4. Monday Evening

5. Tuesday Morning

6. Tuesday Evening

7. Wednesday Morning

8. Wednesday Evening

9. Thursday Morning

10. Thursday Evening

11. February Snowstorm (snowday)

12. Superstorm Sandy

13. Aim: How can we explain wind?

14. Wind Winds are caused by differences in air pressure
Often caused by changing temperature or water vapor content (humidity)

15. Air Pressure Gradient Gradient = change in air pressure distance
The closer the isobars, the higher the pressure gradient
The higher the gradient, the higher the wind speed

16. Gentle gradient 8mb/100 miles Low wind speeds Steep pressure gradient
1028
1008
1012
1024
1016
1020
1020
Steep pressure gradient
12mb/100 miles
High wind speeds
Gentle gradient
8mb/100 miles
Low wind speeds

17. Measuring Wind Anemometers measure wind speed
Measured in mph and knots
1 knot = 1.15 mph

18. Anemometer
Wind Vane

19. Wind Direction Winds are named by the direction from which they blow.
A southerly wind is coming from the SOUTH

21. Wind Movement
Wind moves from areas of HIGH pressure to areas of LOW pressure

22. What do you see? How is the air moving?.

23. Describe what you see in your notes next to the picture.

24. How High and Lows form
Stop! How do you think a low pressure center forms? Think about how there are no clouds and the processes that require evaporation

25. High Pressure Associated with sinking air.
Rotates outward and clockwise in the NH
Cooler air sinks and creates clear skies that we associate with H pressure systems
Called anticyclones

26. Draw the High pressure

27. Low Pressure Warmer, unstable air
Air rises and eventually cools forming clouds
Rotates inward and counterclockwise in the NH
Also called cyclones

28. Draw the L pressure

29. TTYP: why do we get cool winds from the ocean during the day?
Hint, it has to do with pressure

30. Land vs. Sea Breeze

31. Sea Breezes
During day: land is warmer (lower specific heat), water is cooler
high temp = low pressure over land, higher pressure over water.
Winds blow from water to land (sea breeze)

32. Land Breezes
During night: land cools down faster (lower specific heat), water is warmer
Low temp = high pressure over land, lower pressure over water
Winds blow from land to water (land breeze)