Vertical structure - The atmosphere

Atmosphere can be divided up into well-marked horizontal layers mainly based upon temperature.
1. Troposphere
2. Stratosphere
3. Mesosphere
4. Thermosphere
Troposphere
1. Lowest layer, where turbulence and weather most marked
2. contains virtually all water vapour and 75% molecular mass of the atmosphere
3. general decrease of temp at a rate of 6.5 degrees Celsius/km
4. Tropopause - temp inversion layer which acts like a lid on weather and the troposphere
Stratosphere
1. Second layer, 50km troposphere upwards.
2. contains much of the Ozone
3. maximum temperature occurs at the stratopause (may exceed 0 degrees Celsius)
  1. Temp increase due to the low density of air at this height.
Mesosphere
1. above the stratopause average temps increase to about -90 degrees Celsius - rise again after 80 km due to the Ozone and Oxygen molecules absorbing radiation
  1. This temp inversion is called the mesopause
2. Pressure low here decreasing from 1 mb at 50 km to 0.01 mb at 90km (surface pressure = 1000 mb)
Thermosphere
1. Atmospheric densities very low
2. Molecular and atomic oxygen absorb solar radiation at this point.

Resource summary

	Created by Sharondeep over 11 years ago