Temperature Conversion You may need to use this Chart to complete your Station model

Mapping a Temperature Field Page 8 Isotherms- Station model Lines connecting points of equal temperature 43 Station model Temperature (always in ºF)

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QUESTIONS SE, ISOTHERMS 50°F Page 8 SE, ISOTHERMS 50°F LOWER LATITUDES WARMER TEMPERATURES b/c higher angle of insolation 0.029°F/ km 0.012°F/ km

Mapping a Pressure Field Page 9 Mapping a Pressure Field Isobars- __________________________________________________________________ Isolines that connect points of equal pressure on a weather map

QUESTIONS Page 9

QUESTIONS ??? 0.013 mb/ km 0.003 mb/ km Construct a station model Page 9 ??? 0.013 mb/ km 0.003 mb/ km Construct a station model

Crushing Cans Air Pressure Observe the demonstration Page 10 Air Pressure Observe the demonstration What is happening? Why? Describe it in terms of high and low pressure 8

Pressure and Wind What is the cause of air pressure? Page 10 What is the cause of air pressure? ________________________________ The weight of the Earth’s atmosphere 9

Pressure and Wind Page 10 REVIEW What instrument is used to measure wind Speed? What instrument is used to measure air pressure? Barometer Anemometer 10

Page 10 Normal air pressure @ sea level is 1013.3 millibars or 29.92 inches of mercury

Let’s do some pressure conversions Millibars (mb) Inches of Mercury 1030.0 29.95 29.41 1000.0 28.62 30.42 1014.0 996.0 29.53 969.1 Page 10

What is wind caused by? Page 10 Pressure differences due to the Unequal heating of Earth’s surface ________________________________________________________________________ Examples: Land vs. Water Poles vs. Equator Dark Forest vs. Snow Field __________________________________________________ Winds distribute regions of high pressure to low pressure

Pressure and Wind What instrument is used to measure wind Speed? Page 10 What instrument is used to measure wind Speed? Anemometer 14

Winds are named for the direction ________________________________ Caused by differences in air pressure (horizontal movement of air parallel to Earth’s surface) Page 10 Wind- Winds are named for the direction ________________________________ Example: a. Wind from southwest= ________________________ b. Breeze blowing onshore from sea= _____________ of origin or where they come from south westerly wind Sea breeze

Winds Winds blow from areas of high pressure to areas of low pressure Page 10 Winds blow from areas of high pressure to areas of low pressure

Wind Direction Due to the Earth’s _______________ we experience the _____________________. In the Northern Hemisphere winds are deflected to the _________________ In the Southern Hemisphere winds are deflected to the _________________ Page 10 ROTATION CORIOLIS EFFECT RIGHT LEFT

Consequences of Rotation: the Coriolis effect Page 10

CLOSE ISOBARS= STRONG WINDS A measurement of the change in air pressure over a distance is called pressure gradient. If the gradient is large, air will move faster to try and balance the difference. (This makes the wind blow harder) CLOSE ISOBARS= STRONG WINDS Isobars- Page 10 Lines connecting points of equal air pressure

Example of Isobars on a Weather Map Page 10 Example of Isobars on a Weather Map B C Where will the winds be the Strongest? Weakest ?

Pressure and Density Decrease with ALTITUDE