Air Pressure and Winds

Chapter 6

Mercury Barometer

Aneroid Barometer

Aneroid Barometer and Barograph

Atmosphere Thickness and

Pressure at Altitude

• 50% below 6km altitude

• 90% below about 18km

• 0.00003% above 100km

Sealevel Pressure = 14.7 lb/in2 or 1013 mb

Orem Pressure =12.5 lb/in2 or 860 mb

Figure 1-20, p. 22

Orem

Pressure Changes

with Altitude

Pressure Variations with Temperature

Adjusting to Sea-Level Pressure

Planes Fly at Constant Air Pressure Level

Isobars

Factors Affecting Wind

Sea Breeze Caused by Pressure Gradient

Coriolis Effect

Geostrophic Wind

Effect of Friction

Gradient Wind

Surface High and Low Pressure Systems

Wind Measurement

Wind VanePrevailing Wind

Cup AnemometerAerovane

Wind Rose

Chapter 6

END