The Earth's
Atmosphere - Chapter 1
Composition & Structure of the Atmosphere
- The Earth's atmosphere is held in place by gravity.
- The atmosphere is densest at the surface and rapidly thins
upward.
- 97% of the atmosphere is found within 18 miles of the
Earth's surface.
- Gasses that make up the atmosphere
- Changes in atmospheric CO2
- Atmospheric pressure
- measurement units
- 14.7 lbs/inch2 = 1013 millibars =
1 atmosphere = 29.92 inches of Hg = 760mm of Hg
- measuring air pressure
- Vertical Distribution of Atmospheric Pressure
- Ozone
- Thermal Structure of the Atmosphere (from lowest to
highest elevation)
- troposphere
- environmental lapse rate - 3.6oF/1000 feet or
0.65oC/100 meters
- if sea level temperature is 80oF,
at 40,000
feet temperature is -64oF
- at about 48,000 feet, lapse rate remains constant with
elevation increase (tropopause)
- contains water vapor and huge amounts of dust which act
as condensation nuclei
- tropopause height differences (colder air more dense, warmer air less dense, tropopause higher in tropics)
- stratosphere
- temps remain nearly constant to 12 miles (65,000 ft) and then increase rapidly to the stratopause (30 miles (160,000 ft). Max ozone at approximately 25 miles.
- mesosphere
- thermosphere
- Thermal Structure of the
Atmosphere