Air Pressure and Winds
Chapter 6
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
Factors Affecting Wind
Sea Breeze Caused by Pressure Gradient
Effect of Friction
Surface High and Low Pressure Systems
Wind Measurement
Wind VanePrevailing Wind
Cup AnemometerAerovane