Physical Geography 101
Temperature Structure of the Atmosphere
Temperature and Elevation
Lower atmosphere: increased elevation = decreased temperature.
Temperature decreases at constant rate:
Lapse Rate 6.4°C/1000 meters
Structure of the Atmosphere
Troposphere
0-14 km
Lower atmosphere
- Contains most of the weather that affects us
- significant amounts of water
- abundant aerosols (fine liguid and solid particles)
Tropopause
approx. 14 km (varies in elevation with seasons)
Level at which temperature stops decresing with altitude and begins increasing
Stratosphere
14 - 50 km
High altitude air mass - low water and dust content
Ozone layer is found in this layer
Mesosphere 50-85 km
Thermosphere 85-500 km
Exosphere >500 km
Air Density
Increased elevation results in decreased air density
Temperature Inversion
Temperature increases with increasing elevation.
Occurs when:
- ground loses radiation to the air
- ground is colder than the air
Annual Temperature Cycle
Temperatures vary annually - based on variations amount of insolation (axial tilt).
Land vs. Water Temperatures
Coastal areas:
- Generally cooler than inland areas
- Lower annual and daily variations
Four thermal properties of water and land explain why.
1) Penetration
2) Specific Heat
3) Convection
4) Evaporation
Inland vs. Coastal Temperatures
Coastal areas: Less variation in daily and annual temperature.
Inland areas: More variation in daily and annual temperature.